description
stringlengths 2.98k
3.35M
| abstract
stringlengths 94
10.6k
| cpc
int64 0
8
|
|---|---|---|
This is a continuation application Ser. No. 07/068,223 filed June 29, 1987 and now U.S. Pat. No. 4,834,786.
BACKGROUND OF THE INVENTION
This invention relates to a method of manufacturing an optical fiber-preform, and more particularly to a method of manufacturing a preform for an asymmetrical optical fiber.
As used herein, the term "asymmetrical optical fiber" is defined to mean that type wherein a common glass cylindrical cladding contains a plural fibers prepared from the glass having different properties from the cladding glass; all the fiber act as core, or some of them function as stress-applying parts; all the glass fibers are integrally embedded in the cladding; and at least one of the plural glass fibers is positioned apart from the central axis of the cladding. In contrast, as shown in FIG. 1, the conventional single mode optical fiber contains only one core 20 extending along the central axis of cladding 10.
Description may now be made with reference to FIGS. 2A to 2C of an asymmetrical optical fiber FIG. 2A or 2B represents a first example of an asymmetrical optical fiber. Throughout the figures set forth, reference numeral 10 denotes a cladding. Two cores 20 are lengthwise embedded in cladding 10. Core 20 is formed of the glass having a larger refractive index than that of cladding 10 so as to cause light beams transmitted through core 20 to perform a substantially total reflection at an interface between cladding 10 and core 20. Two cores are positioned apart from the central axis of cladding 10.
Referring to the above-mentioned twin-core type optical fiber, the type of FIG. 2A wherein two cores 20 are as spaced from each other as to prevent light beams passing therethrough from interfering each other can be applied as a sensor, if two cores 20 are made to have different properties. When external environmental factors such as atmospheric temperature and pressure are applied to the optical fiber, changes appear in the state of light transmitting through cores 20. If cores 20 are let to have different properties in advance, it is possible to detect the magnitude of received external environmental factors from the difference between the state of light in one core and that in the other core.
If two cores 20 are positioned near to each other as shown in FIG. 2B, then light transmitted therethrough can be coupled together. Therefore, the twin-core type optical fiber can be applied as a coupler or isolator.
A second example of asymmetrical optical fiber shown in FIG. 2C is referred to as "a polarization-maintaining optical fiber." In the second example of FIG. 2C, only one core 20 extends along the central axis of cladding 10. Two stress-applying parts 30 are embedded lengthwise in cladding 10. Stress-applying parts 30 are prepared from glass material having a larger thermal expansion coefficient than cladding 10.
The above-mentioned polarization-maintaining optical fiber is characterized in that even when light is transmitted while the fibers are warped, the polarization at the input end can be sustained even though light is transmitted through a long distance. Therefore, said polarization-maintaining optical fiber can be applied in a wide field including a sensor like a fiber gyroscope and coherent optical communication based on only a particular polarization of light.
In obtaining an asymmetrical optical fiber, a preform which is previously manufactured by the method described below is elongated to have the predetermined diameter.
The conventional method of manufacturing a preform for an asymmetrical optical fiber involves the rod-in-tube method or pit-in-tube method. Description may now be made of these prior art methods.
As illustrated in FIG. 3A, cladding-mother rod 11, core-mother rod 21, stress-applying-mother rods 31 are provided in advance Mother rods 11, 21, 31 can be produced by the widely known processes such as VAD (vapor-phase axial deposition), OVPO (outside vapor phase oxidation) and MCVD (modified chemical vapor deposition).
Thereafter, holes 14 for insertion of core-mother rod 21 and stress-applying-mother rod 31 are perforated in cladding-mother rod 11 by means of drill 40. Each hole 14 is mentioned as "drilled-pore" hereinafter. Later as shown in FIG. 3C, core-mother rod 21 and stress-applying-mother rod 31 are inserted into corresponding drilled pore 14.
Later as indicated in FIG. 3D, heating is externally applied to cladding-mother rod 11 by means of, for example, flames 44 of burner 42. Thus, the boundaries between the inserted mother rods 21, 31 and cladding-mother rod 11 are fused together, thereby providing a perfectly integrated transparent preform 90.
The preform for the twin-core type optical fiber shown in FIGS. 2A and 2B is fabricated in the same manner as mentioned above.
The conventional rod-in-tube process and pit-in-tube process are accompanied with the under mentioned difficulties. First, limitation has to be imposed on the size of a preform to be obtained. If it is attempted to obtain a long preform, a necessarily long drilled-pore 14 will have to be perforated in cladding-mother rod 11. However, any present technique cannot perforate such a long drilled pore through a glass rod, thus imposing a certain limitation on the length of a preform to be fabricated.
Secondly, impurity contamination or scratches tend to appear on the inner wall of drilled pore 14 or the surface of core-mother rod 21 and stress-applying mother rod 31. Therefore, when the preform is drawn to provide an optical fiber, an impurity may diffuse into the core or bubbles will appear in the fiber. These events lead to the transmission loss of light passing through the core.
SUMMARY OF THE INVENTION
This invention has been accomplished in view of the above-mentioned circumstances and is intended to provide a method of manufacturing a preform for an asymmetrical optical fiber, which can resolve the aforementioned difficulties accompanying the conventional process and ensure the manufacture of a long asymmetric optical fiber and can obtain low transmission loss.
To attain the above-mentioned object, the present invention provides a method of manufacturing a preform for an asymmetric optical fiber which comprises:
(a) the step of fixing a plurality of transparent glass rods in parallel relationship;
(b) depositing glass soot around said fixed glass rod, thereby providing a single porous glass layer having the predetermined shape so as to wrap the plural glass rods; and
(c) thermally fusing the porous glass layer, thereby fabricating an entirely integrated transparent preform.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the structure of the ordinary symmetrical optical fiber;
FIGS. 2A to 2C respectively set forth the various asymmetrical optical fibers;
FIGS. 3A to 3D show the conventional method of manufacturing a preform for an asymmetrical optical fiber;
FIGS. 4A to 4C indicate the sequential steps of manufacturing a preform for the polarization-maintaining optical fiber of FIG. 2C representing the present invention;
FIG. 5A to 5C set forth the sequential steps of fabricating a core-mother rod involved in the preform for asymmetrical optical fiber used in the embodiment of FIG. 4A to 4C;
FIGS. 6A and 6B indicate the refraction index profile across the core-mother rod and stress-applying-mother rod used in the embodiment of FIG. 4A to 4C.
FIG. 7 is an enlarged view of burner 66 indicated in FIG. 4C;
FIG. 8A and 8B illustrate the manner in which glass soot is deposited in FIG. 4C;
FIG. 9 shows the heating process for converting the porous preform obtained in FIG. 4C into a transparent preform;
FIGS. 10 and 11 set forth the sectional view of a polarization-maintaining optical fiber obtained from the preform manufactured by the method of this invention;
FIGS. 12 and 13 indicate the method for applying the present invention to the manufacture of a preform for a twin-core type optical fiber; and
FIG. 14 is a sectional view of a twin-core type optical fiber obtained from a preform manufactured by the method illustrated in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 4A to 4C collectively show a method of manufacturing a preform for a polarization-maintaining optical fiber of FIG. 2C, embodying the present invention. According to this embodiment, core-mother rod 21 and two stress-applying-mother rods 31, 31 are first provided These mother rods are arranged parallel as illustrated in FIG. 4A, and securely set by means of a pair of disc-shaped fixing jigs 58. Three rod-inserting holes 60 are perforated in a line in disc-shaped paired fixing jigs 58. Core-mother rod 21 is taken into the central rod hole, and stress-applying-mother rods 31, 31 are inserted into two rod holes formed on both sides of the central hole. Mother rods 21, 31, 31 are securely set in place by bolt 62 threadedly inserted radially into disc-shaped jig 58.
Above-mentioned core-mother rod 21 and stress-applying-mother rods 31, 31 can be manufactured by the previously described known processes VAD, OVPO, and MCVD.
It is desired for the reason given below that the core-mother rod 21 contains predetermined thickness of cladding portion integrally wraps core portion. Description may now be given with reference to FIGS. 5A to 5C of the VAD process of forming core rod 21.
Referring to 5A, reference numeral 46 represents a burner for core soot. Raw gas 48 of core soot is supplied to burner 46. The core soot resulting from the reaction of the raw gas is sprayed and deposited on a support plane (not shown) which constitutes the distal end face of a quartz rod, thereby providing core-soot deposited rod 22a. Reference numeral 50 is a burner for ejecting cladding soot. Burner 50 is supplied with raw gas. The cladding soot generated by the reaction of raw gas is sprayed and deposited on the surface of rotating core-soot deposited rod 22a, thereby providing cladding soot deposited layer 22b. A deposited mass of glass soot is thermally dehydrated in a furnace by applying a proper dehydrant such as SOCl 2 . Heating temperature applied at this time is defined to be lower than that level at which core soot and cladding soot are fused to render deposited layers 22a, 22b are vitrified. Later, the preliminarily heated mass is held in tubular furnace 54 provided with heating means 56 (FIG. 5B). In this tubular furnace, the whole mass is turned into a transparent glass-like state A glass bar produced in tubular furnace 54 is elongated to the predetermined diameter, thereby providing core-mother rod 21 (FIG. 5C).
FIG. 6A indicates the refraction index profile across core rod 21 and glass composition thereof As seen from the illustration, the refraction index (1.4643) of the core portion is made larger than that (1.457) of the cladding portion in order to ensure the prescribed property of an optical fiber. To attain the above-mentioned distribution of refraction index, the core portion is prepared from fused silica doped with germanium, and the cladding portion is composed of pure fused silica.
The cladding portion of core-mother rod 21 has a function of preventing the OH group released during the steps later described with reference to FIGS. 4B and 4C from approaching near the core portion. The reason why the intrusion of the OH group should be prevented is that the polarization-maintaining optical fiber is generally applied in the single mode. Namely, in the single mode, the cladding near the core also takes part in assisting the transmission of light beams If, therefore, the OH group is retained in the neighborhood of the above-mentioned cladding near the core, light beams is noticeably absorbed, resulting in a large transmission loss. The aforementioned dehydration of the glass soot structure during the fabrication of core-mother rod 21 is intended to exclude the OH group from core-mother rod 21.
The cladding portion of the core-mother rod should have a certain thickness in order to fully exhibit its function. If the cladding portion is made underly thick, the undermentioned difficulties will arise. When an optical fiber shown in FIG. 2C is fabricated, an asymmetrical stress exerted by stress-applying parts 30 does not reach core 20, thus failing to ensure a full polarization effect. If, therefore, this fact is taken into account, it is preferred that cladding portion should have such a thickness as corresponds to about 4 times the diameter of core portion.
Stress-applying-mother rod 31 can also be prepared by the aforementioned VAD process However, stress-applying parts 30 should have a larger thermal expansion coefficient than cladding 10. Further, as seen from the refractive index profile of FIG. 6B, stress-applying-mother rod 30 should have a smaller refractive index than cladding. When, therefore, cladding is formed of pure fused silica, and stress-applying rod 31 is prepared from fused silica, then it is advised to apply dopants capable of reducing the refractive index, for example, boron or fluorine. In this invention, the dopant concentration is defines to the about 15-20 mol % in the case of boron and about 2 mol % in the case of fluorine. Further, if required, germanium, too, may be applicable as a dopant The dopant concentration of germanium is defined to be about 5-6 mol %, under the condition in which the refractive index does not become larger than in the case of pure silica.
An assembly of mother rods fixed in the aforementioned manner is fitted to glass lathe 64 shown in FIG. 4B. While the assembly is rotated in the direction of the indicated arrow, the surface of rods 21, 31 is cleaned by flame polishing involving the application of burner 66. Flames should advisably be formed of a mixture of oxygen and hydrogen or high frequency plasma. If the surfaces of rods 21, 31 are considerably soiled, it is advised to add gases containing fluorine or chlorine to the flames, thereby to ensure the etching effect.
Later as shown in FIG. 4C, glass soot 12 for cladding is sprayed around rods 21, 31, while the rod assembly is rotated in the direction of the indicated arrow. As a result, single porous cladding 91 is provided to wrap rods 21, 31. No limitation is imposed on the process of generating glass soot 12. In the VAD process, for example, it is possible to apply multi-layer-burner 66. FIG. 7 is an enlarged view of the multi-layer-burner 66. Reference numeral 71 denotes a central tubular member; reference numeral 72 shows a second tubular member; reference 73 indicates a third tubular member; and reference 74 represents a fourth or outermost tubular member. Raw gas is supplied through the tubular members to produce glass by the CVD (chemical vapor deposition) process.
The deposition of porous cladding 91 by aforementioned multi-layer-burner 66 is performed, for example, under the following conditions.
______________________________________(Types of raw gas and flow rate):Central or first tube: SiCl.sub.4 130 cc/minAr (carrier) 200 cc/minSecond tube H.sub.2 8000 cc/minThird tube Ar 700 cc/minFourth tube O.sub.2 8000 cc/min(Burner traverse rate) 100 cc/min(Rotation speed of rod assembly) constant(Measurements of rods)Core rod length 450 mmDiameter of core-mother rod 21 12 mmDiameter of stress-applying-mother rod 10 mm(Density of porous cladding 91) 0.45 (upper limit)(Time required 11 hrdeposition of glass soot)(Diameter of final preform) 52 mm (upper limit)______________________________________
In the above-mentioned embodiment, the rotation of the rod assembly for the deposition of glass soot was set at the constant speed. However, the rotation need not be limited to the uniform speed, depending on the sectional shape of the intended optical fiber.
Namely, if it is intended to preform an optical fiber which finally assumes a substantially circular section, the rod assembly is rotated at a reduced speed when occupying the position of FIG. 8A, and at an elevated speed when set as indicated in FIG. 8B, thereby enabling glass soot 12 to be deposited in a large amount in an interspace between core rod 21 and stress-applying rod 31. Nor it is necessary to rotate the rod assembly all the time, but the glass soot may be deposited in the lengthwise direction with the rotating mother rod assembly brought to rest at the predetermined point This process actually consists of the steps of rotating the rod assembly for a little while, and then stopping the rod rotation and depositing glass soot a second time in the lengthwise direction. This method is applicable where it is intended to prepare an optical fiber having various sectional shapes, and more effective in the case of a circular section.
The mother rod assembly wrapped with porous cladding 19 illustrated in FIG. 4C can be converted into a transparent preform by being heated in the furnace. During this process, the paired fixing jigs 58 (FIG. 4A) which have supported rods 21, 31 up to this point are removed. Then as shown in FIG. 9, the porous preform is held in furnace 76, while core-mother rod 21 exposed at the center of the porous cladding 91 is suspended by wire 78. It is advised that wire 78 be prepared from a material such as platinum which is possessed of high resistance to heat and corrosion The reason why wire 78 is demanded to have high corrosion resistance is that where necessary, a corrosive gas of the chlorine or fluorine base may sometimes be supplied into furnace 76. The process (FIG. 9) of holding the porous preform in the furnace with paired jigs 58 removed has to be taken for the undermentioned reason.
Porous cladding 91 has a density of about 0.15-0.5 g/cm 3 . When entirely converted into transparent glass by fusing, porous cladding 91 has its volume reduced to 1/6-1/2 of the original one. Since, however, porous cladding 91 is prevented from being shrinked in the lengthwise direction by embedded mother rods 21, 31, it is necessary for the porous cladding 91 to retain a degree of freedom for shrinkage in the radial direction. Unless, therefore, heating is applied without removing paired jigs 58, the obtained transparent preform has its section converted into an elliptic shape after vitrification (FIG. 10).
Nevertheless, the elliptic shape of FIG. 10 itself offers the undermentioned merits When polarization-maintaining optical fibers are spliced together, it is necessary to be informed in advance of the polarizing plane in the transmitted light. In the case where a fiber has a circular section, an optical method has to be applied in order to define polarization axis. Since, however, in the case of the elliptic sectional shape of FIG. 10, shorter axis 81 and longer axis 82 coincide with the polarizing plane of transmitting light, the operation of splicing polarization-maintaining optical fibers is advantageously facilitated.
The properties of a polarization-maintaining optical fiber obtained by drawing the transparent preform obtained in the aforementioned embodiment in accordance with the conventional process of fabricating an optical fiber are show below:
Transmission loss:
0.25 dB/km (measured wave length 1.55 microns)
Cross-sectional shape:
as illustrated in FIG. 11
Beat length between the orthogonal modes
4 mm
Since, as mentioned previously, the conventional polarization-maintaining optical fiber is applied in a single mode, limitation is imposed on a relation between the core diameter and relative refraction index difference. When, therefore, the polarization-maintaining optical fiber is applied in a greater length than several meters, the undermentioned formula (1) has to be satisfied in order to guarantee the substantial single mode. ##EQU1##
Consequently, deposited glass porous cladding 91 (FIG. 4C) should have its thickness so defined as to cause the finally obtained optical fiber to satisfy the above-mentioned condition.
Referring to the above formula (1), ξ represents the operating wavelength; a means the radius of a core; n denotes the refractive index of the core; and Δ shows a relative refraction index difference.
Description may now be made of a method embodying the present invention for the preforming of a twin-core type optical fiber The process described with reference to preforming a polarization-maintaining optical fiber is almost equally applied in the preforming of a twin-core type optical fiber In this preforming process, however, the mother rod assembly has no member 21 to be connected to suspending wire 78 shown in FIG. 9 central projecting.
Consequently, the undermentioned processes may be selectively applied as occasion demands. The first process comprises, as shown in FIG. 12, the step of securing setting transparent glass bar 13 prepared from the same material as cladding glass at midpoint between two core-mother rods 21. Thereafter two core-mother rods 21 and a transparent glass bar 13 are securely fixed to jig 58, the same type of glass soot as previously described is deposited on the above-mentioned mother rod assembly. The resultant porous preform can be suspended in the furnace as in FIG. 9 by connecting wire 78 to transparent glass bar 13.
The second process comprises the step of suspending two core-mother rods by wires 78 as shown in FIG. 13. A twin-core type optical fiber obtained by either of the above-mentioned two preforming processes was drawn by the customary method Determination was made of the properties of the samples of the twin-core type optical fiber, the results being set forth below.
______________________________________Transmission loss 0.55 dB/km (core 1)(measured wavelength: 1.3 microns): 0.60 dB/km (core 2)Sectional shape and refraction as shown in FIG. 14indices of the various portionsof the core assembly:______________________________________
Unlike the conventional rod-in-tube method, the present invention can manufacture the preform for an asymmetrical optical fiber without perforating a drilled-pore, and consequently no limitations are imposed on the length of the preform.
In the present invention, the dimensional precision of the obtained preform depends on that of the mother rod assembly shown in FIG. 4A. Improvement in the dimensional precision of the mother rod assembly of the present invention can be realized more easily than in the perforation precision demanded of the conventional method. Therefore, the preform with high dimensional precision can be obtained
Further, in the present invention, since a diffusion of impurity or a scratch can be excluded from an interface between cladding and core, the preform with low transmission loss can be obtained.
|
Disclosed is a method of manufacturing a preform for an asymmetric optical fiber which comprises the steps of (a) fixing plural transparent glass rods involving at least one core-mother rod functioning as the core in said optical fiber in parallel relationship, (b) depositing glass soot around an assembly of said plural parallel fixed glass rods, thereby providing a single porous cladding bearing the predetermined shape, and (c) vitrifying the porous cladding by thermal fusion, thereby providing the entirely integral transparent preform. The above method does not involve any process of perforating a drilled-pore which is needed inevitably in conventional method. Therefore, it is possible to obtain a long preform with high dimensional precision, and to fabricate the optical fiber with low transmission loss.
| 2
|
BACKGROUND
[0001] Bowfishing is a method of fishing that uses a specialized arrow having a string tethered to the arrow and to a reel mounted on the bow. The string is used to pull or reel in the fish after it is struck by the arrow so the fish can be retrieved or landed. Bowfishing arrows use a “fish point” with barbs that diverge outwardly and rearwardly to the hold or grip the fish and prevent it from coming off the arrow as it is being pulled or reeled in.
[0002] Once the fish is landed, the arrow must be removed from the fish. It should be appreciated that pulling the arrow back through the fish with the barbs extended would be difficult and it would tear and mutilate the flesh of the fish in the process. Accordingly, depending on the type of fish point being used, the barbs either need to be reversed or collapsed or the fish point must be removed from the end of the arrow so the arrow can be pulled back through the fish. Thus, if the arrow does not penetrate all the way through the fish when it is shot, conventional fish points require the bowfisherman to force the arrow all the way through the body of the fish so the fish point projects through the side of the fish in order to reverse or collapse the barbs or to remove the fish point from the end of arrow. Attempting to force the arrow through the fish and then attempting to remove the fish point or attempting to reverse or collapse the barbs while a fish is struggling is difficult and typically requires the bowfisherman to set down his bow so he can use both hands. It is also time consuming and can result in injury to the bowfisherman.
[0003] Accordingly, there is a need for an improved bowfishing arrow which solidly holds the fish until it is landed, but which also allows the arrow to be quickly and easily removed from the fish after it is landed, does not require the fish point to be forced through the fish in order to collapse or reverse the barbs, and which can be accomplished using only one hand so the bowfisherman does not need to set down the bow to remove the arrow from the fish.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a perspective view of an embodiment of the bowfishing arrow in the shooting position.
[0005] FIG. 2 is a perspective view of the bowfishing arrow of FIG. 1 in the locked position.
[0006] FIG. 3 is a perspective view of the bowfishing arrow of FIG. 1 in the unlocked position.
[0007] FIG. 4 is a partial cross-sectional view of an embodiment of a bowfishing arrow when in the shooting position.
[0008] FIG. 5 is a partial cross-sectional view of the bowfishing arrow of FIG. 4 when in the locked position.
[0009] FIG. 6 is a partial cross-sectional view of the bowfishing arrow of FIG. 4 when in the unlocked position.
[0010] FIG. 7 is a partial cross-sectional view of another embodiment of a bowfishing arrow when in the shooting position.
[0011] FIG. 8 is a partial cross-sectional view of the bowfishing arrow of FIG. 7 when in the locked position.
[0012] FIG. 9 is a partial cross-sectional view of the bowfishing arrow of FIG. 7 when in the unlocked position.
[0013] FIG. 10 is an enlarged view of one embodiment of the barbs cooperating with a locking pin and showing the barb in the shooting position.
[0014] FIG. 11 is an enlarged view of the barb and locking pin of FIG. 10 and showing the barb in the locked position.
[0015] FIG. 12 is an enlarged view of the barb and locking pin of FIG. 10 and showing the barb reversed and in the unlocked position.
DESCRIPTION
[0016] Referring to the drawings wherein like reference numerals indicate the same or corresponding parts throughout the several views, FIG. 1 illustrates one embodiment of a bowfishing arrow 10 . The arrow 10 is comprised of a shaft 12 having nock 14 at a proximal end a fish point 16 at its distal end. An aperture 18 is located near the nock 14 for tethering the string (not show) to the arrow 10 . It should be appreciate that the aperture 18 may be sized to receive a stop screw (not shown) for the Safety Slide® system available from AMS LLC, 1064 Hemlock Lane, Stratford, Wis. 54484, as well known to those of skill in the art.
[0017] The shaft 12 is comprised of a main stem 20 with an outer sleeve 30 which is movable with respect to the main stem 20 . In one embodiment as shown in FIGS. 4-6 , the main stem 20 may be a conventional solid shaft arrow as is typically used for bowfishing which is typically made of fiberglass or carbon, but other suitable materials, such as wood, aluminum or other materials may also be used. A solid core main stem 20 may be desirable for the added weight and stiffness provided by solid core shafts to minimize planing of the arrow when it enters the water and for more hitting power to punch through the scales or tough flesh of the fish.
[0018] In the embodiment of FIGS. 4-6 , the distal end of the main stem 20 has a central bore 22 . The central bore 22 receives a coil spring 24 and a slidable locking pin 26 . An alignment peg 28 projects outwardly from the locking pin 26 and through an oblong opening 32 near the distal end of the main stem 20 and a mating oblong opening 34 in the rearward shank 44 of the fish point 16 such that the slidable locking pin 26 is moveable with respect to the main stem 20 and fish point 16 as described in more detail later.
[0019] The outer sleeve 30 has a length that extends over the main stem 20 from the end of the fish point 16 toward the nock 14 , but terminates a short distance before the aperture 18 near the nock 14 on the main stem 20 , such that the outer sleeve 30 is capable of moving longitudinally with respect to the main stem 20 . An aperture 36 is provided in the outer sleeve 30 to receive the alignment peg 28 projecting from the locking pin 26 and extending through the oblong apertures 32 , 34 in the main stem 20 and rearward shank 44 . It should be appreciated that when the outer sleeve 30 is moved longitudinally with respect to the main stem 20 , the alignment peg 28 projecting through the aperture 36 causes the locking pin 26 to move with the outer sleeve 30 such that the alignment peg moves longitudinally within the bore 22 of the main stem 20 , the purpose for which will be described in more detail later.
[0020] The fish point 16 includes a cylindrical body 40 with a conical tip 42 and a rearward shank 44 . The conical tip 42 may be integral with the cylindrical body 40 or the conical tip 42 and cylindrical body 40 may have mating internal and external threads such that the tip 42 is threadably removable and replaceable as is well known to those of skill in the art.
[0021] The rearward shank 44 has a central bore 46 sized to receive the distal end of the main stem 20 which is securely fixed therein. It should be appreciated that a length of the distal end of the main stem 20 which is inserted into the central bore 46 may have a stepped-down outer diameter, so that when the distal end of the main stem 20 is fully inserted into the central bore 46 , the outer diameter of the main stem 20 and the outer diameter of the rearward shank 44 are flush, providing a smooth transition between rearward shank 44 and the main stem 20 . However, it is not necessary for the main stem 20 to have a stepped-down outer diameter because a slight step at their transition will not affect sliding of the outer sleeve 30 , since the transition between the end of the rearward shank 44 and the main stem 20 is sufficiently rearward of the end of the outer sleeve that there is no chance for the outer sleeve to catch on the slight stepped transition even when the outer sleeve 30 is moved to its most rearward position.
[0022] The cylindrical body 40 has an outer diameter substantially the same as the outer diameter of the outer sleeve 30 . Thus, the transition from the larger diameter cylindrical body 40 to the smaller diameter rearward shank 44 results in a shoulder 48 (see FIG. 6 ). The shoulder 48 has a height substantially the same as the thickness of the wall of the outer sleeve 30 . Thus, when the distal end of the outer sleeve abuts the shoulder 48 , the outer diameters of the cylindrical body 40 and the outer sleeve are flush creating a smooth transition from the fish point 16 to the outer sleeve 30 as the arrow penetrates the fish.
[0023] A slot 49 extends through the cylindrical body 40 to pivotally receive opposing barbs 50 , 52 which pivot about pivot pin 54 extending through the cylindrical body 40 as illustrated in FIGS. 4-6 . FIG. 4 shows the barbs 50 , 52 in the shooting position. FIG. 5 shows the barbs 50 , 52 in the locked position. FIG. 6 shows the barbs 50 , 52 in the unlocked position.
[0024] FIGS. 7-9 illustrate an alternative embodiment of the arrow 10 A which utilizes a hollow shaft for the main stem 20 A. Hollow shaft arrows are well known in the art and are typically made of aluminum or carbon but may be made of any other suitable materials. In this embodiment, the construction of the arrow 10 A is substantially the same as previously described, except it should be appreciated that because the main stem 20 A is hollow, the central bore 22 for receiving the spring 24 and locking pin 26 is provided by inserting a plug 25 to serve as the backstop for the coil spring 24 and the locking pin 26 . Thus, as in the previous embodiment, the alignment peg 28 projects outwardly from the locking pin 26 and through an oblong opening 32 near the distal end of the main stem 20 A and a mating oblong opening 34 in the rearward shank 44 of the fish point 16 such that the slidable locking pin 26 is moveable with respect to the main stem 20 and fish point 16 as described in more detail later.
[0025] The outer sleeve 30 has a length that extends over the main stem 20 A from the end of the fish point 16 toward the nock 14 , but terminates a short distance before the aperture 18 near the nock 14 on the main stem 20 A, such that the outer sleeve 30 is capable of moving longitudinally with respect to the main stem 20 A. An aperture 36 is provided in the outer sleeve 30 to receive the alignment peg 28 projecting from the locking pin 26 and extending through the oblong apertures 32 , 34 in the main stem 20 A and rearward shank 44 . It should be appreciated that when the outer sleeve 30 is moved longitudinally with respect to the main stem 20 A, the alignment peg 28 projecting through the aperture 36 causes the locking pin 26 to move with the outer sleeve 30 such that the alignment peg moves longitudinally within the bore 22 of the main stem 20 A, the purpose for which will be described in more detail later.
[0026] In the embodiment of FIGS. 7-9 , the fish point 16 is the same as described in connection with the previous embodiment. The distal end of the main stem 20 A is received within the rearward shank 44 as previously described. The distal end of the main stem 20 A may have a stepped-down length as previously described for insertion into the central bore 46 or the entire length of the main stem 20 A may have the same diameter resulting in a slight step between the transition of the rearward shank 44 to the main stem 20 A. As previously described, a slight step at the transition of these two components will not affect sliding of the outer sleeve 30 , since the transition between the end of the rearward shank 44 and the main stem 20 is sufficiently rearward of the end of the outer sleeve that there is no chance for the outer sleeve to catch on the slight stepped transition even when the outer sleeve 30 is moved to its most rearward position.
[0027] Also as in the previous embodiment, the cylindrical body 40 has an outer diameter substantially the same as the outer diameter of the outer sleeve 30 . Thus, the transition from the larger diameter cylindrical body 40 to the smaller diameter rearward shank 44 results in a shoulder 48 (see FIG. 6 ). The shoulder 48 has a height substantially the same as the thickness of the wall of the outer sleeve 30 . Thus, when the distal end of the outer sleeve abuts the shoulder 48 , the outer diameters of the cylindrical body 40 and the outer sleeve are flush creating a smooth transition from the fish point 16 to the outer sleeve 30 as the arrow penetrates the fish.
[0028] Also as in the previous embodiment, a slot 49 extends through the cylindrical body 40 to pivotally receive opposing barbs 50 , 52 which pivot about pivot pin 54 extending through the cylindrical body 40 as illustrated in FIGS. 7-9 . FIG. 7 shows the barbs 50 , 52 in the shooting position. FIG. 8 shows the barbs 50 , 52 in the locked position. FIG. 9 shows the barbs 50 , 52 in the unlocked position.
[0029] For clarity, FIGS. 10-12 show an enlarged view of only one of the barbs 50 as it cooperates with the locking pin 26 , in each of the respective shooting, locked and unlocked positions applicable in both embodiments described above. It should be appreciated that opposing barb 52 has the same configuration as the barb 50 and cooperates with the locking pin 26 in the same way, except it would be a mirror image to the cam 50 shown in FIGS. 10-12 . The barb 50 includes an eccentric lobe 56 with a central aperture 58 through which the pivot pin 54 extends and about which the barb 50 pivots. The eccentric lobe 56 has a small radius edge surface 60 , an abrupt edge surface 62 which defines a cam 64 and a large radius surface 66 .
[0030] In use, the barbs 50 , 52 are moved to the shooting position as shown in FIGS. 1, 4 and 10 or as shown in FIGS. 1, 7 and 10 , depending on the embodiment. When in the shooting position, the locking pin 26 engages the small radius edge 60 of the lobe 56 , loosely holding the barbs in the shooting position due to the bias of the coil spring 24 . When shot, the arrow 10 will typically penetrate all the way through the body of the fish such that the fish point 16 will be located on the opposite side of the fish's body. Once the bowfisherman begins to pull on the string tethered to the arrow, the fish will begin to slide down the shaft 12 toward the barbs 50 , 52 . Once the fish's body makes contact with the barbs 50 , 52 , the barbs are forced outwardly to the locked position as shown in FIGS. 2, 5, and 11 or FIGS. 2, 8 and 11 depending on the embodiment, clamping the locking pin 26 between the cams 64 . It should be appreciated that even if the arrow does not penetrate through the fish, the resistance from the flesh of the fish as the arrow is being pulled by the string will cause the barbs to be forced outwardly to the locked position and clamping the locking pin 26 between the cams 64 .
[0031] As best illustrated in FIG. 11 , it should be appreciated that the cam 64 prevents the barbs 50 , 52 from further rotating outwardly because the abrupt edge 62 abuts the spring biased locking pin 26 . Likewise, the body of the fish pressing against the barbs 50 , 52 prevents the barbs from rotating back toward the shooting position. Thus, the barbs 50 , 52 will remain in the locked position until the fish is landed and it is desired to remove the arrow from the landed fish.
[0032] To remove the arrow from the fish, a simple one-handed maneuver is all that is required as explained step-by-step below. The bowfisherman simply grabs the outer sleeve 30 of the arrow with one hand to lift the fish above the ground a short distance. By gripping only the outer sleeve 30 , the entire weight of the fish is carried by the barbs 50 , 52 of the fish point 16 which binds the locking pin 26 between the cams 64 . While continuing to grip only the outer sleeve 30 , the bowfisherman than gives a single quick and forceful downward thrust on the arrow, immediately followed by an upward thrust. This action generates a momentum that multiplies the force or weight of the fish acting on the barbs 50 , 52 . When the fish's added weight (due to the momentum) hits the locked barbs, it is sufficient to overcome the clamping force of the cams 64 acting on the locking pin 26 permitting the locking pin to move upwardly within the bore 22 compressing the spring 24 . As the locking pin 26 moves upwardly within the bore, the peg 28 received within the aperture 36 permits the sleeve 30 to move upwardly relative to the main stem 20 , 20 A and fully retracting the locking pin from between the cams 64 . With the locking pin 26 fully retracted, the barbs 50 , 52 pivot about the pivot pin 58 from the locked position to the unlocked position as shown in FIGS. 3, 6 and 9 due to the weight of the fish acting on the barbs. With the barbs in the unlocked position, the fish simply slides off the end of the arrow over the fish point 16 .
[0033] To move the barbs back to the shooting position, the bowfisherman simply forces the barbs rearwardly with the fingers of his bowhand without needing to set down the bow. With the barbs in the shooting position, the bowfisherman is ready to shoot another fish.
[0034] Various embodiments of the invention have been described above for purposes of illustrating the details thereof and to enable one of ordinary skill in the art to make and use the invention. The details and features of the disclosed embodiments are not intended to be limiting, as many variations and modifications will be readily apparent to those of skill in the art. Accordingly, the scope of the present disclosure is intended to be interpreted broadly and to include all variations and modifications coming within the scope and spirit of the appended claims and their legal equivalents.
|
A bowfishing arrow and method of bowfishing. The bowfishing arrow includes a shaft having a main stem. A locking pin is slidably movable within a bore of the main stem. A fish point with a pair of pivoting barbs is secured to the distal end of the main stem. An outer sleeve is longitudinally movable with respect to the main stem and the locking pin is engaged with the outer sleeve to move with the outer sleeve. The barbs pivot between a shooting position, a locked position, and an unlocked position. When in the locked position, an end of the locking pin is clamped between cams preventing the barbs from pivoting to toward the unlocked position and the shooting position until the fish is landed. A one-handed maneuver is all that is required to release the arrow from the fish after it is landed.
| 0
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements in combustion chambers and a more particularly, but not by way of limitation to a multi-stage combustion chamber for producing gases and super heated steam in combination for creating power in a fuel efficient manner and substantially fuel free manner.
2. Description of the Prior Art
At the present time, oils, such as fossil fuels, are widely used as an energy source to produce gases for use in rocket engine and other aerial propulsion mechanism, and in turboprop and turbojet engines in aircraft, and the like. Natural gases, artificial gases, coals and oils are also being utilized as an energy source for the heating of waters in boilers to produce saturated steam and in superheating boilers to produce dry high temperature super heated steam. These present day methods of producing power have certain disadvantages in that the fuel consumption is frequently high in relation to the power produced, and the burning of the fuels in the usual manner may create pollution in the surrounding atmosphere. In the present day energy crisis and with the current concern with air pollution, these disadvantages are augmented, and any means of reducing fuel consumption while increasing the power output, and alleviating the pollution problem, is of considerable importance.
SUMMARY OF THE INVENTION
The present invention contemplates a novel gas and steam generator which has been particularly designed and constructed for overcoming the foregoing disadvantages and which combines the gases, such as produced for use in rockets, with the super heated steam, as produced by the boilers, to provide a mixture of gases and steam as a power source. Gases, either natural or artificial, coals, oils, magnesium, hydrogen, borax and borons or the combination of one or more may be utilized in the novel device. The novel generator comprises a plurality of combustion chamber assemblies secured in interconnected relationship, with the combustion chamber of each assembly being in communication with the combustion chamber of the preceding and succeeding assemblies through restrictive orifice means. The temperature and velocity of the gases at the restrictive orifices is considerable, and water, steam and combustible materials are introduced simultaneously at the orifices for ignition of the combustible materials and heating of the water to produce saturated or superheated steam in combination with the gases of combustion as a power source. The high temperatures and pressures maintained within each combustion chamber by the restrictive outlet thereof produces a great burning efficiency for the combustible materials and, in addition, the ratio of water to fuel is relatively high as, for example, 90% water and 10% fuel, thus resulting in the production of high velocity exhaust gases and steam in combination for a power source utilizing a minimum of fuel consumption, and with a minimum of unburned fuel escaping into the atmosphere. The novel apparatus is simple and efficient in operation and economical and durable in construction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional elevational view of a gas or steam generator embodying the invention.
FIG. 2 is a view taken on line 2--2 of FIG. 1.
FIG. 3 is a schematic diagram of a power generator system embodying the invention.
FIG. 4 is a view similar to FIG. 3 illustrating a modified power generator system embodying the invention.
FIG. 5 is a view similar to FIGS. 3 and 4 illustrating still another power generator system embodying the invention and particularly for burning hard to ignite fuels.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, reference character 10 generally indicates a gas or steam generator apparatus comprising a plurality of interconnected combustion chamber assemblies 12, 14, 16, and 18. It is to be noted that, whereas four combustion chamber assemblies are shown in FIG. 1, substantially any desired number of the chamber assemblies may be utilized as will be hereinafter set forth. The chamber assembly 12 comprises a jacket 20, preferably constructed from a suitable thermal insulating material, such as ceramic or the like, and having a combustion chamber 22 provided therein. A sectional housing 24-26 surrounds the jacket 20 and is preferably constructed from a suitable metallic material, but not limited thereto. A first helical groove 28 is provided around the outer periphery of the jacket 20 and has one end in communication with a passageway or bore 30 extending radially through the housing section 26, and the opposite end in communication with an internal passageway 32 and a suitable mixer valve 34. The valve 34 extends through the jacket 20 and is in open communication with the chamber 22. A second helical groove 36 is provided around the outer periphery of the jacket 20 and has one end in communication with a passageway or bore 38 (FIG. 2) extending radially through the housing section 26, and preferably in diametrically opposed relation to the bore 30. The opposite end of the groove 36 is in communication with a second internal passageway 40 of the mixer valve 34. Both the bores 30 and 38 are open to the exterior of the housing section 26 for a purpose as will be hereinafter set forth.
The mixer valve 34 is disposed at one end of the chamber 22 and the opposite end of the chamber 22 is open through a restriction or restrictive orifice 42, which restricts the discharge of fluid from the chamber 22 and thus creates a considerably high pressure and temperature in the chamber during operation of the device 10. A bore 44 extends through the sidewall of the jacket 20 to provide communication between the chamber 22 and a bore 46 provided in the housing section 24. The bore 46 is enlarged at 48 for receiving a suitable igniter 50, such as a spark plug or the like. The bore 48 is in substantial axial alignment with a bore 52 provided in an end plate 54 which bears against the outer end of the housing section 24 as particularly shown in FIG. 1, and for a purpose as will be hereinafter set forth. The bore 52 provides access to the igniter 50 for facilitating installation thereof, removal thereof, or the like, as is well known.
A first passageway 56 extends through the housing section 26 into communication with a bore 58 provided in the sidewall of the jacket 20 and terminating at the orifice 42. A second passageway 60 similar to the passageway 56 and diametrically opposite with respect thereto extends through the housing section 26 into communication with a bore 62 provided in the jacket 20 and terminating in the orifice 42 opposite disposed with respect to the bore 58. The passageways 56 and 60 are both open to the exterior of the housing section 26 as particularly seen in FIG. 1. The orifice 42 is open to a second combustion chamber 64 which is provided in the assembly 14.
The assembly 14 comprises a sectional insulating jacket 66-68 surrounding the combustion chamber 64 and encased in a sectional housing 70-72 secured in end-to-end abutting relation with the housing 24-26 in a manner as will be hereinafter set forth. As hereinbefore set forth, one end of the chamber 64 is in communication with the chamber 22 through the orifice 42, and the opposite end thereof is provided with a restrictive orifice 74, which restricts the discharge of fluid from the chamber 64 in order to create a considerable pressure within the chamber 64 during operation of the apparatus 10. A first bore 76 extends through the sidewall of the jacket section 68 for providing communication between the orifice 74 and a passageway 78 provided in the housing section 72. A second bore 80 extends through the sidewall of the jacket section 68 in substantially diametrically opposed relation to the bore 76, and provides a communication between the orifice 74 and a passageway 82 provided in the housing section 72. The passageways 78 and 82 are both open to the exterior of the housing section 72 for a purpose as will be hereinafter set forth. As will be more particularly seen in FIG. 1, it is preferable that the volume or cross-sectional area of the combustion chamber 64 be greater than the volume or cross-sectional area of the combustion chamber 22.
The orifice 74 is open to a third combustion chamber 84 which is provided in the assembly 16. A sectional insulating jacket 86-88 surrounds the chamber 84 and is encased in a sectional housing 90-92 which is secured in end-to-end abutting relation with the housings 24-26 and 70-72 as will be hereinafter set forth. It is preferable that the volume or cross-sectional area of the chamber 84 be greater than the volume or cross-sectional area of the chamber 64. Whereas one end of the chamber 84 is open at the orifice 74, the opposite end is also provided with a restriction or orifice 94 which restricts the discharge of fluid from the chamber 84 in order to build up pressure within the chamber 84 during operation of the apparatus 10. A first substantially radially extending bore 96 is provided in the sidewall of the jacket section 88 and extends from the orifice 94 into communication with a passageway 100 provided in the housing section 88. A second bore 102 extends substantially radially through the sidewall of the jacket section 88 and is preferably diametrically opposed with respect to the bore 96, but not limited thereto. The bore 102 extends from the orifice 94 into communication with a passageway 104 provided in the housing section 88. The passageways 100 and 104 are open to the exterior of the housing section 88, and the orifice 94 is open to a chamber 106.
Generally speaking, the temperature within the chamber 106 is not as great as the temperature generated within the chambers 22, 64, and 84, and, as a result, it is considered that the use of an insulating jacket is not required around the chamber 106. As a result, the housing section 92 is preferably axially extended and is provided with a recess 108 therein, which forms a portion of the inner periphery of the chamber 106. The outer end of the recess 108 is open, and a flanged sleeve 110 is disposed against the outer end of the housing 92 and is provided with a recess 112 therein of a size generally complementary to the size of the recess 108 and cooperates therewith to form the remaining portion of the inner periphery of the chamber 106. A centrally disposed discharge port 114 is provided in the sleeve 110 which communicates between the chamber 106 and the exterior of the sleeve 110 for a purpose as will be hereinafter set forth. The sleeve 10 and outer portion of the housing section 88 cooperate to form the assembly 18.
The sleeve 110 is preferably provided with an outwardly extending circumferential flange 116 extending around the outer periphery thereof. The outer diameter of the flange 116 is preferably substantially the same as the outer diameter of the plate 54, and the flange 116 is provided with a plurality of circumferentially spaced apertures 118 disposed in substantial axial alignment with a plurality of circumferentially spaced bores 120 provided in the end plate 54. A rod member 122 extends through and between each of the associated pairs of aligned bores 118 and 120 and is secured therein by means of suitable nuts 124, which may be securely tightened whereby the sleeve 110 is constantly urged in a direction toward the end plate 54, thus securely retaining the housing sections 24-26, 70-72, and 90-92 in end-to-end abutting relationship. Of course, it will be apparent that any other suitable means of securing the housings together may be utilized, and it may be preferable to provide suitable sealing means between the housing.
Referring now to FIGS. 3, 4 and 5, schematic arrangement for a plurality of uses of the device 10 are shown. FIG. 3 shows a system which may be efficiently utilized when burning fuels which are relatively readily ignitable with the usual spark plugs or standard igniters. These fuels are preferably oils, natural gas, artificial gases, alcohols, and the like. In this system, it is preferable that only two stages or two combustion chambers, such as the chamber 22 and the chamber 106, be utilized, with the chamber 22 being the first stage combustion chamber and the chamber 106 being the second stage combustion chamber. The igniter 50 is operably connected with a suitable source of power (not shown) in any well known manner (not shown) to provide an ignition or spark within the chamber 22 when required. The passageway 30 is operably connected with a source of air or oxygen (not shown) for directing an oxygen supply into the mixer valve 34 for discharge into the chamber 22, and the passageway 38 is suitably connected with a source of a suitable fuel, such as hereinafter set forth, and supplied the fuel to the mixer valve 34 for discharge into the chamber 22. The oxygen (or air) and fuel are delivered to the respective helical grooves 28 and 36 and are directed simultaneously to the interior of the mixing valve 34, and the valve 34 injects the fuel and oxygen simultaneously into the chamber 22 through a plurality of ports 35 (FIG. 2) at a great velocity, and the fuel and oxygen are efficiently mixed for ready ignition in the chamber 22 by the ignitor 50. The gases of the combustion within the chamber 22 will be forced through the restrictive orifice 42 to build up pressure in the chamber 22 in excess of the pressure of the end product in the outlet 114 shown in FIG. 1.
As hereinbefore set forth, stage two of the system shown in FIG. 3 is the combustion chamber 106, and is the saturated or superheating chamber area. It is preferable that the volume of the chamber 106 be approximately sixty percent larger than the volume of the chamber 22 of stage one. Inlets 56 and 60 represent the inlets for water or recycled steam which is metered through the orifice 42. The steam or water is heated or reheated to form usable saturated or superheated steam in the chamber 106 and outlet 114. The product present at the outlet 114 is a combination of gases and steam from the combustion chambers 22 and 106. The product or mixture moves from the outlet 114, through a conduit means 130, and to a steam turbine 132, or the like. The fluid stream then passes to a suitable cold water pump 136 to cool superheated steam down to saturated steam which then travels through conduit means 136 for return to the reservoir 126. Passage of the fluid stream from the reservoir 126, through a conduit means 128, and the inlet means 56 completes the recycling of saturated steam.
Referring to FIG. 4, a modification of the invention is shown which may utilized in the handling of materials which are not readily ignitable by spark plugs, and the like. For example as is well known, liquified coals with water or oil are substantially impossible to ignite. In this embodiment or system, only three stages may be necessary, with stage one being the combustion chamber 22, which functions in the same manner as hereinbefore set forth in connection with the system shown in FIG. 3. The chamber 62 shown in FIG. 1 is the second stage, and the chamber 106 shown in FIG. 1 is the third stage for the system shown in FIG. 4. The hot products of the combustion in the chamber 22 emitting from the orifice 42 become the ignitor for the combustion chamber 64. In this system, the passageway or inlet 60 is in communication with the fuel, such as liquified coal, and the liquified coal is pumped through the inlet 60 and metered into the orifice 42. The inlet 56 is in communication with a source of oxygen or air and the compressed air is metered into the restrictive orifice 42. The air and liquified coal are ignited by the heat from the chamber 22 and the combustion thereof takes place in the chamber 64. The gases of the combustion in the chamber 64 pass through the restrictive orifice 74 and into the combustion chamber 106 (third stage). The chamber 106 is the heating chamber for water or saturated steam or superheated high pressure, high temperature dry steam. Inlet 76 is in communication with a recycle fluid reservoir 138 through conduit means 140 and the inlet 82 is also in communication with a source of water or saturated steam or superheated steam and the water or saturated steam or superheated steam is metered into the restrictive orifice 74 and heated to saturated steam or superheated steam. Gases from the combustion chambers 22 and 64 will heat the water or saturated steam or superheated high pressure, or dry high temperature steam and gases within the chamber 106. The steam and gases are released through the orifice 114 and pass through a suitable solid waste trap means 142 wherein solid particles are removed from the fluid stream. The gases and steam then move to a turbine 144, or the like, and return to the recycle reservoir 138 through conduit means 146 whereby the saturated steam may be recycled through conduit means 140 to passageway 76.
FIG. 5 illustrates a modification of the invention which may be utilized in the burning of materials which create great heat but are difficult to ignite, such as magnesium, aluminum, boron, borox, or the like. In this system, all four stages or combustion chambers 22, 64, 84 and 106 are preferably utilized, with the chamber 22 being the first stage, chamber 64 being the second stage, chamber 84 being the third stage, and chamber 106 being the fourth stage. The chamber 22 is utilized in substantially the same manner as hereinbefore set forth. The burned gases in the chamber 22 being forced through the restrictive orifice 42 create a build up of pressure which exceeds the pressure at the orifice 114. In the second stage chamber 64, the inlet 60 is in communication with a supply of water liquified magnesium, or the like, which is pumped and metered into the restrictive orifice 42, and the inlet 56 is in communication with a source of water which is also pumped and metered into the orifice 42. Heat from the combustion chamber 22 will ignite the magnesium to burn with the oxygen. The magnesium will then burn all of the oxygen from the steam, leaving hydrogen to be burned in the third stage chamber 84. The burning ratio of magnesium is: H 2 O--MgO 2 =4 parts of hydrogen to one part of magnesium.
The combustion gases from stages one and two will be forced through the restrictive orifice 74 into the third stage chamber 84, including the hydrogen which did not burn in the combustion chamber 64. Compressed air (or oxygen) is metered through the inlets 76 and 82 and through the orifice 74 and is forced into the chamber 84 by the superhot gases, thus igniting and burning the hydrogen in the chamber 84. The fourth stage chamber 106 is again the heating chamber to heat the water or saturated steam or superheated steam and is used in the same manner as in the systems of FIGS. 3 and 4. Water is pumped and metered through the inlets 100 and 104 into the restrictive orifice 94 and heated or reheated to saturated steam or superheated steam, and is forced through restrictive orifice 114. Gas and steam will be forced through a solid waste trap 148 as a source of energy that can be used to drive a steam turbine 154, or the like. The steam will be recycled from the turbine 154 through line 156 to a suitable recycle reservoir 150 and back through a conduit means 152 to the inlets 100 and 104, thus completing the recycle operation.
This use of magnesium as an energy source is particularly important when it is considered that magnesium is the most plentiful resource for fuel on this planet, but has never before been utilized to produce steam for a power source. Thus, not only is a previously untapped source utilized, but also the system of the invention is substantially pollution free and is economically feasible in construction and operation.
From the foregoing it will be apparent that the present invention provides a novel gas and steam generator wherein gases and steam are utilized in combination to provide a power source for a work operation. The apparatus comprises a multi-stage combustion chamber assembly wherein fuels of relatively ready ignition or fuels of difficult ignition may be utilized for an efficient creation of power for a work operation. Water is added to the fuels to to provide oxygen for combustion of the fuel to produce the steam and the steam is combined with the gases of combustion of the fuels in a manner that greatly conserves the quantity of fuel necessary for the power output.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.
|
A gas and steam generator having at least two interconnected combustion chambers wherein water in combination with combustible materials is utilized for creating power for a work operation, each combustion chamber being provided with a reduced nozzle-type outlet for creating great pressures and temperatures within the respective chambers, and each combustion chamber being arranged for receiving combustible materials therein for burning thereof. The initial combustion chamber preferably receives a fuel-oxygen mixture at the inlet end thereof for ignition, with the products of the combustion being maintained at a high pressure and temperature by the restrictive nozzle-type outlet of the chamber. Steam and additional combustible materials are introduced at the nozzle outlet of the chamber for ignition and passage into a next stage combustion chamber whereby additional heat and force is produced for ultimate delivery of great power for a work operation. The water/fuel ratio is relatively high, which results in a reduction of fuel for fuel efficiency in the production of power for the work of operation.
| 5
|
BACKGROUND OF THE INVENTION
TECHNICAL FIELD
This invention relates to internal combustion engines, which are employed in model aviation airplanes or other applications that can utilize two-stroke or four-stroke internal combustion engines. The four-stroke internal combustion engines are more desirable for their quietness of operation and high torque ability at lower Revolutions Per Minute. The four-stroke internal combustion engines that are currently available are heavier than desired and require constant maintenance and adjustment of the gears, cams, valves, valve seats, push rods, rod bearings, springs, rocker arms, bolts, lock nuts and various other parts.
REFERENCE CITED
United States Patents
U.S. Pat. No. 968,200 August 1910 Scott . . . 123/73
U.S. Pat. No. 1,165,135 December 1915 Seitz . . . 123/78
U.S. Pat. No. 3,418,993 December 1968 Scheiterlein et al . . . 123/195
U.S. Pat. No. 4,907,544 March 1990 Burrahm . . . 123/26
BRIEF SUMMARY OF THE INVENTION
The present invention provides a four-stroke internal combustion engine with means for the injection of a fuel and air mixture into the combustion chamber of the engine using stationary port placement and synchronized port rotation using gears. An Important feature of the present invention is that it requires no cams, push rods, rocker arms, springs or valves.
DESCRIPTION OF THE DRAWINGS
Other objects and attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein,
FIG. 1 is a view of a preferred embodiment of the instant invention,
FIG. 2 is a view showing the relationship of the intake and exhaust passages of the instant invention,
DESCRIPTION OF THE INVENTION
Referring to the drawings, wherein like numerals indicate like or corresponding parts, a preferred embodiment of the four-stroke internal combustion engine is generally shown at 10 of FIG. 1 .
The engine includes a hollow crankshaft 12 , which is disposed in the engine housing or block 14 the same as a two-stroke internal combustion engine. The piston rod 16 connects the hollow crankshaft 12 to the piston 18 . The power gear 20 is mounted to the hollow crankshaft 12 so as to rotate with it. The ported gear 22 with the port 24 is rotably mounted in the engine housing 14 and engaged with the power gear 20 so as to rotate one-half of a rotation every time the hollow crankshaft 12 and power gear 20 rotates one whole revolution.
The gear cover 56 is mounted on the engine housing 10 and contains the port 28 , channel 30 , port 38 , channel 40 and gear bearing 58 .
As the hollow crankshaft 12 rotates counter-clockwise from the position shown in FIG. 1, the crankshaft intake port 44 in the hollow crankshaft 12 is positioned to close with respect to the engine housing port 42 in the engine housing 14 , thereby sealing the crankshaft housing chamber or crankcase 26 and compressing the air-fuel mixture inside the crankshaft housing chamber 26 , the chamber 32 , channel 30 and port 28 . As the piston 18 continues downward, the power gear 20 rotates the ported gear 22 causing the port 24 to present itself to the port 28 allowing the compressed air-fuel mixture to enter the passage 34 and into the cylinder compression chamber 48 when the piston 18 clears the port 34 as shown in FIG. 2 . This completes the first downward stroke.
As the hollow crankshaft 12 continues to rotate in the counterclockwise direction, the piston rod 16 forces the piston 18 upward, passing the passage 34 therefore closing off the cylinder compression chamber 48 and compresses the air-fuel mixture. At this point the crankshaft intake port 44 presents itself to the engine housing port 42 in the engine housing 14 and allows the passage of air into the crankshaft housing chamber 26 along with aspirated fuel, and continues to allow the intake into the crankshaft housing chamber 26 until the piston 18 reaches the upper limit of its travel at the top. This completes the second stroke. The check valve 50 restricts any back flow into the crankshaft-housing chamber 26 during the second stroke.
The compression caused by the piston 18 heats the air-fuel mixture in the cylinder chamber causing the heating element in the glow plug 54 to ignite the air-fuel mixture, forcing the piston 18 into a downward power stroke. As the piston 18 passes the port 36 , the expanded gasses pass through the port 36 on their way out of the engine. The port 24 in the ported gear 22 comes into position allowing the gasses to pass on through the port 38 , the channel 40 , and out to the atmosphere. The piston 18 is now at the extreme downward end of the third stroke. The crankshaft intake port 44 has been closed with respect to the engine housing port 42 throughout the complete third stroke and the air-fuel mixture has again been compressed in the crankshaft housing chamber 26 , the chamber 32 , channel 30 and port 28 .
The port 24 in the ported gear 22 is still in position to allow any remaining burnt gasses to pass through the port 36 to the port 38 and from the cylinder chamber through the bypass 46 between the engine housing and the sleeve 52 .
As the piston 18 starts its upward motion, it forces what remaining burnt gasses that are in the cylinder compression chamber 48 to pass out through the bypass 46 in the engine housing and the sleeve 52 . The crankshaft intake port 44 is again in position with the engine housing port 42 to allow the air-fuel mixture to again fill the crankshaft housing chamber 26 , while the check valve 50 restricts any back flow. This completes the fourth stroke.
|
A four-stroke engine constructed using a gear with a port synchronized to the crankshaft by a power gear, and channels to direct the intake gases from the crankshaft housing into the combustion cylinder and to direct the exhaust gases out of the combustion cylinder into the atmosphere.
| 5
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 11/687,151 filed Mar. 16, 2007, and commonly assigned.
BACKGROUND
Field
[0002] The invention generally relates to valve arrangements for vehicle exhaust systems. More specifically, the present teachings pertain to passive flapper valves for exhaust conduits.
[0003] Many exhaust systems have attempted to use both active and passive valve assemblies to alter the characteristics of exhaust flow through a conduit as the exhaust pressure increases due to increasing engine speed. Active valves carry the increased expense of requiring a specific actuating element, such as a solenoid. Passive valves utilize the pressure of the exhaust stream in the conduit with which the valve is associated.
[0004] Traditionally, even passive valves at their lower expense give rise to problems of unwanted back pressure when the valve is open. There is seen to be a need in the art for a passive valve arrangement which may be utilized totally inside a conduit, which is relatively inexpensive, and is capable of assuming a fully open position which minimizes unwanted back pressure.
SUMMARY
[0005] Accordingly, an exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit includes a valve flap having first and second arcuate edges substantially conforming to curved portions of the exhaust conduit, and first and second linear edges extending between the first and second arcuate edges and providing clearance between the valve flap and an inner surface of the conduit. An axle adapted to pivotally couple the valve flap to the exhaust conduit about a longitudinal axis of the axle is coupled to the valve flap between the first and second arcuate edges such that unequal surface areas of the valve flap lie on either side of the axle. The axle further includes a protrusion at one end thereof adapted to be positioned exteriorly of the exhaust conduit. A bias element is adapted to be coupled between the exhaust conduit and the axle protrusion and is operative to bias the valve flap toward a closed position wherein the first and second arcuate edges of the valve flap contact curved portions of the exhaust conduit. Exhaust pressure may be of a magnitude overcoming a bias force of the bias element to force the valve flap to a fully opened position within the conduit wherein the first and second linear edges of the valve flap contact an inner surface of the valve conduit and are substantially parallel to the longitudinal axis of the conduit.
[0006] In a further aspect of the disclosed teachings, a muffler for an internal combustion engine exhaust system includes a housing having an outer shell, input and output headers closing opposite ends of the shell and a partition inside the housing dividing it into first and second chambers. The partition has at least one aperture therethrough providing for fluid communication between the first and second chambers. A through pipe extends through the input and output headers and the partition and has a first plurality of perforations enabling fluid communication between the through pipe and the first chamber and a second plurality of perforations enabling fluid communication between the through pipe and the second chamber. A valve assembly having a valve flap is positioned inside the through pipe between the first and second pluralities of through pipe perforations. The valve flap rotates about an axle pivotally coupled to the pipe between a fully closed position wherein a first peripheral portion of the valve flap is in contact with an inner surface of the through pipe and a fully opened position wherein a plane of the valve flap is substantially parallel to a longitudinal axis of the through pipe and a second peripheral portion of the valve flap is in contact with an inner surface of the through pipe.
[0007] In still a further aspect of the disclosed teachings, a fluid flow pressure actuated valve assembly for placement inside a tubular conduit includes a valve flap having a first peripheral portion adapted to be in contact with an inner surface of the conduit when the flap is in a full closed position and a second peripheral portion in contact with the inner surface of the conduit in a full open position. An axle is adapted to pivotally couple the valve flap to the conduit about a longitudinal axis of the axle, the axle coupled to the valve flap asymmetrically with respect to a surface area of the valve flap, the axle including a protrusion adapted to be positioned outside the conduit. A bias element is adapted to be coupled between the conduit and the protrusion and is operative to urge the valve flap toward the full closed position.
BRIEF DESCRIPTION OF THE DRAWING
[0008] The objects and features of the disclosed teaching will become apparent from a reading of the detailed description, taken in conjunction with the drawing, in which:
[0009] FIGS. 1A , 1 B are respective side and end views of a valve controlling fluid flow through a conduit, the valve being in a closed position and arranged in accordance with the disclosed teachings;
[0010] FIGS. 2A , 2 B are respective side and end views of the valve of FIGS. 1A , 1 B in a 15° open position;
[0011] FIGS. 3A , 3 B are respective side and end views of the valve of FIGS. 1A , 1 B in a 30° open position;
[0012] FIGS. 4A , 4 B are respective side and end views of the valve of FIGS. 1A , 1 B in a fully open position;
[0013] FIGS. 5A , 5 B are respective side and end views of a first valve axle arrangement in accordance with the present teachings;
[0014] FIGS. 6A , 6 B are respective side and end views of a second valve axle arrangement in accordance with the present teachings;
[0015] FIG. 7 is an end view of the valve of FIGS. 1A and 1B with the pipe contacting the valve flap altered to achieve substantially full blockage of the pipe when the valve is placed in the fully closed position; and
[0016] FIG. 8 is a side cross-sectional view of an exhaust muffler arranged with the valve of FIGS. 1A , 1 B in accordance with the present teachings.
DETAILED DESCRIPTION
[0017] With reference to FIGS. 1A-4B , side and end views of a valve assembly with a valve flap in various operative positions is shown in side and end views of the conduit in which the valve assembly is positioned. Identical elements among these Figures carry the same last two designation numerals.
[0018] An exhaust conduit 102 contains a snap-action valve 100 which includes a spring anchor 104 , a valve spring 106 , an external lever arm 108 , a valve flap 110 , a valve support shaft or axle 112 and a spring attachment arm 114 protruding from axle 112 .
[0019] Valve flap 110 has first and second arcuate edges substantially conforming to an interior arcuate surface of conduit 102 . Flapper 110 additionally has linear side edges 116 and 118 which provide clearance 120 , 122 between flapper 110 and an interior surface of conduit 102 when the flap is in the closed position shown in FIGS. 1A and 1B . Bias element or spring 106 extends between an anchor point 104 on conduit 102 and attachment point 114 of external lever arm 108 . Spring 106 biases flapper 110 toward the closed positioned shown in FIG. 1A . When in the fully closed position, flap 110 resides at an angle other than 90° to a plane extending normal to the longitudinal axis of conduit 102 . The angle of the flap with respect to a cross-sectional normal plane of conduit 102 is designated A.
[0020] In operation, exhaust pressure is incident on flap 110 from the left as viewed in FIGS. 1A-4B . When the exhaust pressure is sufficient to overcome the bias force of spring 106 , the flap 110 will start to rotate about axle 112 . The torque on valve flap 110 is determined by the bias spring force multiplied by the distance d which is the distance d between the axis of the spring and axle 112 . The spring force increases as the valve flap opens and the spring 106 stretches. However, d gets shorter as the valve continues to open resulting in the torque approaching zero as the longitudinal axis of the spring approaches an “over-center” position—i.e., as it approaches intersection with a longitudinal axis of the axle 112 . This nearly over-center positioning of the valve flap as shown at 410 in FIG. 4A and FIG. 4B results in a substantially horizontal position of the flap when in the fully open position. This positioning, in turn, minimizes back pressure in the conduit when the valve is in the fully open position. Additionally, it is to be noted that the conduit itself supplies the stop mechanism for the valve flap in both its fully closed and fully opened positions. In the fully closed position, the arcuate edges of flap 114 contact the interior surface of conduit 102 to define that position. Conversely, when in the fully opened position, as shown in FIGS. 4A and 4B , flap 410 utilizes its lateral linear edges ( 116 and 118 of FIG. 1B ) to come into contact with the inner surface of conduit 402 to thereby provide a stop position for the fully opened position of flap 410 .
[0021] Rotating the valve flap such that the spring approaches the over-center condition also results in an easier maintenance of the valve in the fully opened position.
[0022] FIGS. 5A and 5B show a first axle arrangement suitable for use with the valve assembly disclosed herein. Valve flap 510 rotates within conduit 502 about axle 512 which is placed asymmetrically with respect to the plane of flap 510 . A bias spring 506 extends between anchor point 504 and an attachment point 514 on lever arm 508 . As seen from FIG. 5B , axle 512 which is journaled to conduit 502 via appropriate apertures, extends only so far at its leftmost end as shown in FIG. 5B so as to provide clearance between the axle 512 and spring 506 . With this clearance, the spring goes to near over-center and holds that position until the exhaust flow pressure is reduced significantly. At that point, the valve flap snaps to the closed position. Lever arm 508 protrudes from axle 512 either as a separately attachable element or as an integral protrusion of axle 512 .
[0023] FIGS. 6A and 6B depict an alternative axle arrangement for use with the valve assembly disclosed. In this arrangement axle 612 extends outwardly of the conduit for a distance sufficient that it intersects the ultimate location of spring 606 when in its fully extended position. Hence, in this arrangement, spring 606 will contact axle 612 and wrap around it when the fully opened position is achieved. With this arrangement, since spring 606 wraps around axle 612 , the spring will pull the flap 610 to the closed position as soon as the exhaust flow pressure is reduced to a level unable to overcome the spring force.
[0024] FIG. 7 depicts one approach to achieving nearly full closure of the exhaust conduit by the disclosed valve assembly when the valve flap is put in its fully closed position. As seen from FIG. 7 , clearance areas such as 120 and 122 of FIG. 1 B are substantially eliminated by flattening sides of conduit 700 such that it conforms more nearly to the overall peripheral shape of valve flap 710 . Section 724 and section 726 are flattened areas of conduit 700 to more nearly parallel the linear first and second edges of valve flap 710 . Of course it will be apparent to those skilled in the art that some clearance between the linear edges of valve flap 710 and conduit walls 724 and 726 must be present to prevent jamming of the valve flap upon rotating.
[0025] An exemplary application of the disclosed valve assembly is for an automotive exhaust system muffler, such as that shown in FIG. 8 .
[0026] Muffler 800 has a housing comprised of a substantially cylindrical outer shell 818 closed at input and output ends by an input header 810 and an output header 812 . A partition 814 is attached to outer shell 818 at a position to define muffler chambers 824 and 826 on either side thereof. Partition 814 additionally includes at least one aperture 820 , 822 enabling fluid communication between the chambers 824 and 826 inside muffler 800 . Optionally, sound absorbing material 816 may be placed in one or both interior muffler chambers.
[0027] Extending through muffler 800 by passing through input header 810 , partition 814 and output header 812 is a through pipe 802 . Pipe 802 includes a first plurality of perforations 806 enabling an input section of pipe 802 to have fluid communication with the muffler chamber 824 surrounding it. Pipe 802 has a second plurality of perforations 808 at an output end enabling fluid communication from the chamber 826 surrounding it to pipe 802 .
[0028] Positioned between the first and second set of perforations of pipe 802 is a valve assembly 100 arranged as previously described in conjunction with FIGS. 1A-4B . Hence, in the closed position of valve assembly 100 , exhaust will enter muffler 800 at the input end 828 of pipe 802 as seen in FIG. 8 and will flow through perforations 806 into the sound absorbing material 816 surrounding the pipe in chamber 824 . The exhaust then flows from the first chamber 824 to the second chamber 826 via apertures 820 , 822 in partition 814 . Finally, the exhaust flows from the second chamber 826 through perforations 808 in through pipe 802 and out an exit end 830 of the pipe 802 as seen from FIG. 8 .
[0029] When the exhaust pressure is high enough to overcome the force of bias spring 106 , the valve flap 110 will open to a nearly horizontal position within pipe 802 to essentially have most of the exhaust gas bypass the first and second chambers and their associated sound absorbing material. Since the flap 110 will be substantially horizontal in FIG. 8 in the fully open position, back pressure in muffler 800 is minimized.
[0030] The invention has been described in conjunction with a detailed description of embodiments disclosed for the sake of example only. The scope and spirit of the invention are to be determined from an appropriate interpretation of the appended claims.
|
A passive, exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit is pivotally mounted to an off-center axle for rotation between fully closed and fully opened positions. A bias element forces the valve flap toward the fully closed position. The valve flap is shaped in a manner enabling use of the interior surface of the exhaust conduit to define stops at the full closed and full opened positions. The valve flap shape, in conjunction with the bias element arrangement, enables the flap to lie substantially parallel to a longitudinal axis of the conduit in the fully opened position, which provides for minimum back pressure in the conduit.
| 5
|
FIELD OF THE INVENTION
The present invention relates to the field of ice making. The invention is useful, for example in the making of snow, ice islands and in other large scale ice making processes.
DESCRIPTION RELATIVE TO THE PRIOR ART
In U.S. Pat. No. 4,200,228 there is disclosed a method for the making of snow whereby microorganisms are included in droplets that are sprayed into the air. The microorganisms that are used are of the type which are known to promote ice nucleation. As a result, snow can be made at temperatures that are much higher than are ordinarily possible. A typical microorganism that is useful in this method is a Pseudomonad and particularly Pseudomonas syringae.
In U.S. Pat. No. 4,637,217 there is disclosed a method for accelerating the freezing of sea water. Ice nucleating microorganisms are added to the water source, in this case sea water. The sea water is then distributed, such as by spraying, to make large ice structures. These ice structures are useful for oil drilling platforms in the polar regions. In this application of the ice nucleating microorganisms, the conditions of spraying are adjusted to promote the formation of ice on the surface rather than snow in the air. In addition to spraying, the patent also discloses other methods of distributing the ice nucleated sea water. For example, an area that is surrounded by a dam can be flooded by the nucleated sea water and allowed to freeze.
In these methods, the ice nucleating microorganism is introduced into the water supply prior to distribution of the water for freezing. In a typical snow making method for example, the water that is used is from an on site source such as a pond or stream. The water is pumped up the ski slope to the snow guns using large pumps. These pumps are inside enclosures in order to protect them from the weather and to facilitate maintenance.
The ice nucleating microorganism is usually delivered to the site in dried form. The microorganism is then resuspended in an aqueous medium, typically just water, in a concentrated form. This concentrate is mixed in a tank in the structure that contains the pumps for distributing the water to the ice making system. Since only a small amount of the microorganism is needed to nucleate the source water, only a small amount of this concentrate needs to be injected into the water supply. In a typical installation, a 100 liter suspension of microorganism having a microorganism concentration of 3 g/L will nucleate about 380,000 liters of water and will last for about 10 hours before the tank will need to be refilled with new suspension.
We found that the effectiveness of the ice nucleating microorganism was much greater for a fresh suspension than the suspension that was being used at the end of the 10 hour period. This meant that the amount of suspension that was needed to nucleate the source water increased over time even though the ice making conditions did not change. This increased usage of the microorganism suspension increases the cost. It is this problem that the present invention seeks to solve.
SUMMARY OF THE INVENTION
The present invention provides a method for making ice using ice nucleating microorganisms. The method comprises the steps of:
(a) forming an aqueous suspension of ice nucleating microorganisms;
(b) introducing the suspension into a water source to form an ice nucleated water source;
(c) distributing and freezing the ice nucleated water source.
The improvement is that the suspension of ice nucleating microorganisms is maintained throughout at a temperature below about 13° C.
In the prior art process, the ice nucleating suspension was made using cold source water. The tank is housed in the enclosure with the source water pumps and thus is very warm due to the heat generated by the equipment. Thus, while the outside temperature might be below freezing, the pump house temperature is typically between 20° and 30° C. Thus, even though the ice nucleating suspension is made with cold, e.g. 4° C., water, the temperature in the tank rapidly reaches the pump house temperature. At this temperature, we found that ice nucleating activity (INA) was rapidly lost.
If the temperature of the suspension is allowed to reach the pump house temperature, as much as about 70% of the INA is lost during the 10 hour holding period. In contrast, if the temperature of the suspension is kept at 13° C. or lower, we found that less than about 35% of the initial INA is lost.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with particular reference to the snow making embodiment. It will be understood however, that the invention is equally applicable to other ice making embodiments, such as making ice for load bearing ice structures described in the U.S. Pat. No. 4,637,217 mentioned above and for other uses.
Ice nucleating microorganisms that can be used in the method of the present invention are well known in the art. Any microorganism that has ice nucleation activity can be used in the method. Suitable microorganisms include Pseudomonads such as P. syringae and P. fluorscens, P. coronafaciens and P. pisi. Other microorganisms that are useful in the present invention include Erwina herbicola. The presently preferred microorganism is P. syringae ATCC No. 53543 deposited on Sept. 23, 1986 in accordance with the Budapest Treaty with the American Type Culture Collection in Rockville Md., USA.
Fermentation of the microorganism can be carried out using conventional fermentation techniques. Particularly preferred methods and media are described in copending, commonly assigned patent applications U.S. Ser. No. 910,600 filed Sept. 23, 1986; Ser. No. 944,120 filed Dec. 22, 1986; and Ser. No. 21,949 filed Mar. 6, 1987.
The ice nucleating microorganism is recovered in a dry form. The microorganism from the fermentation can be prepared in dried form in a number of ways. Spray drying and freeze drying are typical examples. Any drying process will reduce the INA to a certain extent. One preferred method that preserves a large amount of the INA that is produced in the fermentor is the process that is described in copending, commonly assigned U.S. patent application Ser. No. 910,552, filed Sept. 23, 1986 entitled "Recovery of Microorganisms Having Ice Nucleating Activity" of Lindsey. In this process, the medium is cooled, concentrated, run into a cryogenic liquid to form pellets and then the pellets are freeze dried at relatively low temperature.
At the time that the ice nucleating microorganisms are to be used, an aqueous suspension of the dried microorganism is prepared. In a typical preparation, 100 g of the dried microorganism is suspended in 100 L of water in a suitably sized tank. The tank can be equipped with a recirculation pump which is run for a period of time to insure that the microorganism is thoroughly suspended. About 15 minutes for the tank of the above illustration is sufficient. The concentration of the microorganism in the tank is not critical. Usually, the concentration is between about 1 and 15 g/L.
According to the present invention, the suspension in this tank is maintained at a temperature of 13° C. or less and preferably 10° C. or less. The suspension is kept at this temperature by a variety of conventional means such as recirculating the suspension through a heat exchanger or refrigerating the tank containing the suspension.
Where the suspension is made from the source water that is to be used to make the ice or snow, the water, as noted above, will typically be quite cold. In such a situation, we have found that the suspension can be maintained in the desired temperature range for long periods by simply insulating the tank containing the suspension. For the 100 L tank described above, closed cell foam insulation having a thickness of about 1.9 cm has been found to be sufficient where the ambient temperature is up to about 25° C.
From the tank holding the suspension, the suspension is injected into the water source that is used to make the ice. The suspension is metered into the source water in a conventional amount to form a nucleated water supply. Under typical snow making conditions, the suspension is metered at a rate such that the final concentration of nucleator in the source water is about 79 μg/L. The nucleated water is then distributed to the ski area by spraying with a snow gun using conventional methods.
In the example presented below, the INA is calculated using conventional techniques. The INA is determined by placing a plurality of microorganism containing water droplets (10 μl) on paraffin coated aluminum foil. The foil is maintained at -5° C. by placing it on a constant temperature bath. Details regarding this procedure are found in the literature, for example, Vali, Quantitative Evaluation of Experimental Results on the Heterogeneous Freezing of Supercooled Liquids, J. Atoms Sci., 28, 402-409 (1971). The INA data that was used for the examples is the INA that is found in the suspension after it has been made from the dried microorganism.
The following examples are submitted for a further understanding of the invention.
EXAMPLES 1-4
Several 6 g samples of dried Pseudomonas syringae were placed into several metal containers, each of which contained 2 liters of water. The starting temperature of the water was 6° C. The microorganisms were suspended by recirculating the contents of the containers using a Serfilco® pump. The resulting suspensions were placed in a variety of constant temperature locations. At various times, samples of the suspensions were tested for ice nucleating activity as described above and for temperature. (The temperature measured for the suspension was sometimes slightly higher than the nominal ambient temperature because of slight variations in the actual ambient temperature and the errors in temperature measurement.) The INA was compared to the INA of the starting suspension. The results are shown in Table I below. Examples 4 and 5 are comparative examples.
TABLE I______________________________________% INA Remaining and Suspension Temp.Ambient TEx. °C. 3.5 hrs °C. 24 hrs °C. 48 hrs °C.______________________________________1 5 93.3 5.5 58.9 5 52.5 52 10 75.9 11 47.9 10.5 33.9 10.53(c) 15 58.9 13.5 12.3 16 0 164(c) 21 44.7 18.5 0 23 0 21______________________________________
The results show a significant improvement in the amount of INA that remains in the suspension if the temperature of the suspension is maintained according to the invention.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
|
The method comprises the steps of:
(a) forming an aqueous suspension of ice nucleating microorganisms;
(b) introducing the suspension into a water source to form an ice nucleated water source;
(c) distributing and freezing the ice nucleated water source.
The improvement is that the suspension of ice nucleating microorganisms is maintained throughout at a temperature below about 13° C.
| 5
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to flow meters employed for the measurement of fluid flow through a fluid pipe line or conduit.
2. Description of the Prior Art
Many approaches to measuring the flow of fluid through a pipe line are employed in the prior art. Typical flow meters employ either a spinning element or a ball in a track. In the meters employing a spinning element the element usually includes several paddles that interact with fluid flowing through the meter causing rotation of the element. This rotation is then measured. Such a prior art arrangement is difficult to assemble and is subject to continual maintenance requirements due to the complexity of the element's structure and its low friction mounting in the housing.
The meters that employ a ball bounded within a track direct all or a portion of the fluid flow through a tangential inlet in the valve allowing the fluid to impinge upon the ball causing the ball to rotate within the track. This rotation is then measured in order to determine the flow rate through the meter. One of the difficulties in using this prior art meter is that due to the centrifugal force of fluid passing through the meter, the fluid can experience a pressure drop and a sharp increase in fluid velocity depending on the arrangement of the inlet and outlet in the meter. These changes in the fluid can substantially reduce the accuracy of the meter.
One prior art procedure for preventing a pressure drop and a sharp increase in fluid velocity is to employ a tangential outlet in the meter. In this manner, once fluid enters the meter, it is directed to a circular track whereupon the fluid flows around the track until it encounters the outlet. Since the fluid does not change its direction of flow in entering the tangential outlet, smoother flow of the fluid out of the valve results avoiding a large pressure drop and a sharp increase in fluid velocity. In addition, the tangential positioning of the outlet allows the centrifugal force of the fluid that is developed as it flows around the track to assist rather than hamper the exit of fluid through the outlet, thus further limiting the pressure drop and the increase in fluid velocity.
The employment of a tangential outlet in combination with a tangential inlet, however, results in a meter that is less compact and necessitates a change in the direction of the fluid line in order to be installed. Moreover, this construction prevents the measurement of fluid flow in a bidirectional manner thus limiting its use to one way flow.
To overcome some of these problems related to tangentially positioned outlets, some prior art meters incorporate a set of vanes adjacent an axial outlet to direct fluid from the interior of the meter to the outlet. Such a meter is disclosed in U.S. Pat. No. 3,805,609. These meters, however, employ a tangential object and are incapable of measuring bidirectionally and of being mounted in-line with the fluid line.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a new and improved meter for measuring fluid flow in a fluid line.
Another object of the present invention is to provide a new and improved meter that may be mounted within a fluid line without displacement in the alignment of the fluid line.
A further object of the present invention is to provide a new and improved fluid flow meter that may be employed to measure bidirectional fluid flow.
Briefly, the above and other objects and advantages of the present invention are achieved by providing an improved flow meter including a housing with a fluid inlet and a fluid outlet that are coaxially defined on opposite sides of the housing. The inlet and outlet are adapted to be connected to a fluid line and are in fluid communication with a chamber defined within the housing. Mounted to the housing and within the chamber are a pair of vane assemblies including a first set of vanes secured to the chamber adjacent to and surrounding the fluid inlet and a second group of vanes secured to the chamber adjacent to and surrounding the outlet.
The first group of vanes functions to direct flow from the inlet to an annular track defined between the outer periphery of the vane assembly and the inner periphery of the chamber. The second group of vanes functions to direct fluid flow from the track to the outlet of the meter.
Mounted within the track is a rotary element intended to interact with the fluid flow through the meter. The rotary element is preferably a ball of a density substantially equal to the fluid in the fluid line and of a smaller dimension than the track. In this manner, fluid flow introduced to the inlet of the meter flows through the first vane assembly into the track causing the ball to move within the track. The fluid is then directed by the second group of vanes to the outlet. The velocity of the fluid causes the ball to rotate within the track at substantially the same velocity as the fluid flow. The rate of rotation of the ball within the track may be measured by an assembly that may include a light emitting diode and a detection device coupled to an appropriate circuit to measure the number of rotations of the ball over a period of time.
In addition, due to the coaxial alignment of the inlet and outlet, fluid flow through the meter may be reversed with equally efficient measurement of the flow rate.
BRIEF DESCRIPTION OF THE DRAWING
The present invention together with the above and other objects and advantages will best appear from the following detailed description of an illustrative embodiment of the invention shown in the accompanying drawing, wherein:
FIG. 1 is a partially cut-away, perspective view of a fluid flow meter constructed in accordance with the present invention;
FIG. 2 is a cross sectional view on a reduced scale of the fluid flow meter of FIG. 1; and
FIG. 3 is a partially cut-away view taken along line 3--3 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Having reference now to the drawing, there is illustrated a fluid pipe line designated as a whole by the reference numeral 10. The pipe line 10 includes pipes 12 and 14 that are employed to conduct fluid from a fluid source such as a water supply to a device such as a water softener. In order to measure and record the flow rate and volume, the fluid line 10 includes a bidirectional flow meter generally designated by the reference numeral 16.
The meter 16 is intended to be mounted in-line with the pipes 12 and 14 in a manner such that the pipes 12 and 14 need not be misaligned to be coupled to the meter 16. In addition, the meter 16 is adapted to measure and record flow bidirectionally thereby eliminating the possibility of improper installation as a result of reversing the meter 16. The bidirectional capability of the meter 16 also allows reverse flow in the line 10, if so desired, once the meter 16 has been installed. Further, the meter 16 is constructed such that the operation and response of the flow meter 16 is linear over a wide range of fluid flow rates thereby enhancing the reliability of the meter 16.
To accomplish these objectives the meter 16 includes a substantially symmetrical housing 18 including a first 20 and a second 22 substantially identical housing portions. Each housing portion 20 and 22 includes a port 24 and 26, respectively, that is adapted to be coupled to one of the pipes 12 and 14. In the illustrated embodiment, the port 24 is coupled to the pipe 12 and is the inlet port and the port 26 is coupled to the pipe 14 and is the outlet port. In addition, once the housing 18 is assembled, the ports 24 and 26 are coaxial. To assemble the housing 18, the housing portions 20 and 24 are secured together by several fasteners 28 and an O-ring or a similar device such as a gasket 30 is mounted at the interface of the joined housing portions 20 and 22 to prevent leakage.
In order to measure the rate of fluid flow, the meter 16 includes a ball 32 that is positioned within an annular track 34 defined by the housing portions 20 and 22. The ball 32 is of a smaller diameter or transverse dimension than the same dimension of the track 34. In this manner, as fluid is introduced into the meter 16, the ball 32 is less likely to be hung up by an accumulation of debris between the ball 32 and track 34. Furthermore, the ball 32 may be fabricated of a material having a density substantially equal to the density of the fluid in the line 10 thus reducing the vibration of the ball 32 within the track 34 during fluid flow.
Some of the problems experienced in prior art meters due to an axial outlet such as outlet 26 are the loss of pressure and the increase in velocity of the fluid as it flows through the meter. In accordance with the present invention, these problems are solved by providing a smooth fluid flow path from the track 34 to the outlet 26. In addition, an axial inlet such as inlet 24 is also a problem in the prior art meters since the direction of fluid from the inlet to the track 34 cannot be imparted to the fluid in a sufficiently smooth manner to avoid pressure loss and an increase in velocity.
To overcome these problems the meter 16 includes a first vane assembly 36 molded on the first housing portion 20 adjacent to and surrounding the inlet 24, and a second vane assembly 38 molded on the second housing portion 22 adjacent to and surrounding the outlet 26. The first and second vane assemblies 36 and 38 are separated by an impervious plate or disc 40 that serves to prevent direct axial flow through the meter 16. The plate 40 may be fabricated from rubber or a similar resilient material.
The first vane assembly 36 serves to direct the fluid flow in a spiral manner from the inlet 24 to the track 34. The fluid flow, in this manner, has both a tangential and radial flow component as it enters the track 34. To accomplish this physical alteration in the direction of the fluid flow, the first vane assembly 36 includes several vanes 42. The vanes 42 are of a curvilinear configuration that begin adjacent to the inlet 24 and gently curve in a radial or spiral direction terminating adjacent to the track 34. In this manner, fluid flowing through the inlet 24 is uniformly directed by the vanes 42 to several different locations in the track 34. Accordingly, the entire flow of fluid does not directly impinge on the ball 32 but, rather, the fluid flow is along a toroidal path about the track 34 resulting in a tangential impingement by part of the fluid against the ball 32. Additionally, since fluid is introduced in front of and behind the ball 32, the ball 32 experiences a pushing force from the fluid behind it and a pulling force due to a venturi or negative pressure effect from the fluid flowing in front of and around the ball 32. This push-pull effect induces the ball 32 to rotate even at very low flow rates through the meter 16 thereby enhancing the meter's utility.
The second vane assembly 38 serves to direct fluid in a spiral manner from the track 34 to the outlet 26 such that the flow has both radial and tangential flow components. This is accomplished in a gradual or smooth manner thereby minimizing pressure loss and velocity increase of the fluid. To provide this smooth direction change the second vane assembly 38 includes several vanes 44 molded onto the housing portion 22 and oriented in a direction opposite to the vanes 42. In this manner, fluid is introduced into the inlet 24 and is directed by the vanes 42 into the track 34 whereupon the ball 32 is rotated within the track 34 under the influence of the fluid. As the fluid flows within the track 34, it interacts with the vanes 44 and is spirally directed from the track 34 to the outlet 26.
The outer periphery of the vane assemblies 36 and 38 as defined by the vanes 42 and 44 with the inner periphery of the housing 18 further define the track 34 along which the ball 32 rotates.
Since the vanes 42 and 44 are molded onto the housing portions 20 and 22, the orientation of the vanes 42 and 44 relative to each other may be altered by rotation of one of the housing portions 20 or 22 relative to the other prior to positioning the portions together. This provides the installer of the meter 16 with the ability to adjust the various flow characteristics of the meter 16.
Moreover, due to the employment of the vane assemblies 36 and 38 in the manner described, the inlet 24 and the outlet 26 are coaxially defined on the housing 18. Consequently, the meter 16 may be mounted in the fluid line 10 without the necessity of displacing the pipes 12 and 14 in order to accomodate ports that are not coaxial such as, for example, tangential ports as employed in prior art meters.
It should also be noted that the vane assemblies 36 and 38 have been described as including vanes 42 and 44, respectively, that are molded on the corresponding housing portions 20 and 22; however, the vanes 42 and 44 could be molded on the plate 40 or positioned within the housing 18 as separate units.
As flow is introduced into the meter 16 as described, the ball 32 is rotated within the track at a rate that is proportional to the rate of fluid flow through the fluid line 10. Since flow is introduced at several locations around the entire track 34 and also exits at several locations around the entire track, some of the flow actually bypasses the ball 32 yet accurate readings are still obtained. This bypass capability further assists in preventing a change in pressure and velocity of the fluid in the line 10 due to the employment of the meter 16.
The rate of rotation of the ball 32 can be measured and displayed thus providing a reading as to the flow rate within the line 10. This measuring and display function is accomplished through the employment, in the preferred embodiment, of an opto-electric pick-up assembly 46. The assembly 46 serves to establish a beam of light across the track 34 that is broken by the ball 32 during each revolution. This action may be counted and recorded by an appropriate assembly well known in the art.
More specifically, the assembly 46 includes a mounting yoke 48 of a configuration that allows it to be mounted on the housing 18. The yoke 48 includes a photo-transistor 50 that is mounted in a passage 52 defined in the yoke 48. The passage 52 is aligned with a passage 54 that extends through the housing 18 and intersects the track 34. A light emitting diode 56 is diagonally mounted on the yoke 48 in a passage 58 defined also in the yoke 48. The passages 52, 54, and 58 are aligned such that light is emitted by the diode 56 and received by the transistor 50.
An appropriate power source is coupled to the diode 56 and the transistor 50 and the output of the transistor 50 is coupled to a counting device. In this manner, as the ball 32 rotates in the track 34, it will break the beam of light emanating from the diode 56 during each revolution. This break in the beam of light is counted and displayed as a function of flow through the line 10.
While the pick-up assembly 46 has been described as of the opto-electric type, other types of pick-ups may be employed. For example, magnetic, resistance, capacitive or ball contact sensing assemblies may be used; particularly, if the fluid in the line 10 is opaque.
While the invention has been described with reference to details of the illustrated embodiment, it should be understood that such details are not intended to limit the scope of the invention as defined in the following claims.
|
A flow meter including a housing with a coaxial inlet and outlet is disclosed. The housing of the flow meter defines an inner chamber including a pair of vane assemblies surrounding the inlet and outlet. A track is defined between the vane assembly and the housing. The meter further includes a fluid responsive member positioned in the track and rotated therein by fluid flow through the meter. The rate of rotation of the member is measured by an assembly mounted on the housing.
| 6
|
BACKGROUND OF INVENTION
[0001] 1. Technical Field
[0002] The present invention related to crocheted balls and, more particularly, relates to crocheted balls having an embroidered portion thereof.
[0003] 2. Related Art
[0004] The utilization of spherical crocheted objects for toys, games and recreations have been increasingly popular over the past several years. Initially, crocheted balls were made and sold as toys through many retailers. Now crocheted balls have many additional uses in sports and recreational activities because they are soft, colorful and inexpensive to produce. Crocheted balls and bags have become very popular for use in sports that utilize soft balls including footbag, juggling, toss ball, kick ball, dodge ball and others. Thus, due to their popularity and wide distribution, spherically crocheted objects make an excellent item for advertising and promotional purposes.
[0005] One of the more popular utilizations of the spherical crocheted objects is for the game of footbag. An originating patent, U.S. Pat. No. 4,151,994, for the game was issued in May 1979 to Robert J. Stahlberger, Jr. the inventor of the game of footbag (Hacky Sack™). The original ball that was used for this game was a leather paneled style of ball shaped like a baseball. Years later, this original invention was improved upon with the introduction of several newer styles of footbags that touted improved characteristics for the playing of the game. These improved characteristics included a softer style of ball and low bounce characteristics that allowed for greater control and ease of use by the footbag players, who enjoyed the ability to “catch” the ball with the foot and perform a much wider array of athletic footbag tricks. One of the more popular ball types for the game has become the crocheted footbag.
[0006] Crochet is a fabric construction that utilizes needlework consisting of the interlocking of looped stitches formed with a single thread and a hooked needle. The popular crocheted ball is a successful implementation of crochet stitching in a round form. Thread types used include cotton, rayon, dacron, polyester or a combination of several thread types. The thread used is of varying degrees of thickness. Depending on the thickness and type of the thread, a crocheted ball will contain larger or smaller stitches which give the ball an appearance of being fuzzier, thicker or rougher. Crocheted balls are made of varying sizes, weights and looseness based on the game played, preference of the participants of the sport, durability and cost. All spherical crocheted objects can be woven by machine or by hand.
[0007] Spherical crocheted objects are woven such that rows contain increasing numbers of stitches expanding outward in a spiral form. Thus, the start of a crocheted ball (the “bottom”) starts with a single stitch; which is added to in a spiral pattern. This spiral construction soon forms a round disc. The spherical shape forms as the disc construction expands and the stitches are tightened to create a curvature. In the middle of the crocheted ball, the rows contain their maximum number of stitches and determine the diameter of the crocheted ball. For instance, if there are 10 stitches per inch then a ball 8 inches in diameter will contain 80 stitches.
[0008] As a crocheted sphere is woven, and after it reaches its maximum diameter, the number of stitches per row is reduced. Thereafter the reduction of each successive row gives the ball its shape and the stitches get tighter and closer together. Before the crocheted sphere weaving is completed, a small hole remains. Before the final closure, the ball is filled with a filling type, which is often plastic resin pellets, bird seed or other types of small or inert filling; then the crocheted object is sealed shut with the final crocheted weave and tied off in a knot. A spherical crocheted object is usually seamless and durable with the final sewing termination.
[0009] The filling of a crocheted ball determines its characteristics: slackness, feel and the best utility.
[0010] Manufacturers have chosen many different filling types and sizes. Crocheted balls are quite durable, seldom rupture and thus can be used in the most active and aggressive games with little chance of breaking open.
[0011] The simplicity and low production cost of the crocheted ball is ideal for many applications in games, sports and toys. Crocheted balls are superior for the purpose of game balls because they are very durable while being malleable and soft at the same time. This offers a longevity not found with paneled balls which tend to break open at the seams. The stresses on the fabrics during the use of crocheted balls are dissipated throughout the stitches of the ball as compared to that of a paneled ball which have limited stitches.
[0012] Prior to this invention, spherical crocheted objects have been limited in their ability to purport messages. Previous utilizations were predominantly limited to fabricating crocheted balls with designs built entirely into the crocheted construction. Thus, the primary method has been to directly crochet images into the actual weaving by means of changing the colors of the threads on each individual stitch, usually by hand, to create the necessary contrast to create such images. Although images and logos implemented on existing crocheted balls can be quite complicated and intricate, the fact remains that crocheted balls are limited by the number of stitches per inch inherent in the manufacture of such balls, usually 10 stitches per inch or less, depending on the thickness of the thread used.
[0013] Alternative utilizations applied to crocheted balls for the purpose of creating a more useful advertising medium have included other attempts to modify their construction. One known attempt has been the addition of a round panel of fabric sewn into the crocheted ball. This panel, which can be of imitation suede or another durable material, is suitable for screen printing and other suitable advertising purposes; however, there are problems with this incarnation. The basic strength of the ball is dubious due to a fixed fabric seam that is incapable of handling the stresses of hard play, and has been known to come undone. Additionally, the fabric is less flexible than the original crocheted stitches so the ball does not function as well for the preferred active sports that require a softer ball.
[0014] Still other manufacturers have attempted variants on crocheted balls to enhance the ability to purport messages or logos. Directly dyeing the crocheted threads is a less successful method of applying words, logos or advertising messages since it is often messy and unprofessional in outcome. Further still, a panel of fabric has been sewn to the exterior of crocheted balls as a means of applying a logo or message. This application is also limited because the size of these fabric pieces must be very small and do not stick well to spherical objects when glued or sewn.
[0015] In summary, spherical crocheted objects are inexpensive and mass-produced items used for various sporting, recreational and advertising purposes. To date, the several known attempts to extend the message-carrying functionality of these crocheted objects have had limited success.
SUMMARY OF INVENTION
[0016] The invention changes the procedure and method by which a spherical crocheted object is made. The spherical object no longer contains the limits of low quality or low resolution graphics for the purpose of adding an image, a message, logo, words, name or motif. Utilizing our specific production process allows for the inclusion of an embroidery step during the construction of the spherical crocheted object, enhancing the usefulness of products, games and diversions that utilize them.
[0017] The embodiment specifies fabrication steps that allow for the addition of an embroidered logo of a limited size. The size restrictions depend upon the size of the final crocheted ball and more specifically, the size of the initial disc of crocheted fabric upon which the embroidery is sewn. This initial disc should not be more than about 30% of the size of the diameter of the spherical crocheted object. Thus, even though crocheted balls are round, our embodiment avoids attempting to crochet on a round object since current technology embroidery equipment does not effectively sew on spherically constructed objects of closed construction, particularly on crocheted or woven balls of loose and fairly thick thread.
[0018] In the current embodiment, spherical crocheted objects, such as crocheted balls, are the recipients of the placement of an embroidery message or logo. Crocheted balls are popularly utilized as toys as well as the primary object of several games and sports, such as juggling and Hacky Sack™, also known as the game of footbag, and other games that require a low impact or soft ball that is durable and often malleable.
[0019] Prior to our embodiment previous methods of carrying logos or other publicity images on spherical crocheted object were limited, of low quality, too complicated and of a decorative or ornamental nature mainly. The inherent limitations of the medium of construction the loose and thick crocheted stitching meant that inexpensive crocheted balls were less effective tools for promotion by those seeking inexpensive toys or objects for advertising or incentive purposes. Previous attempts at utilizing crocheted balls required that the messages or advertising images be constructed during the initial construction of the spherical crocheted object, on a stitch-by-stitch level, by using different colored threads that were woven to form a crocheted ball. Still other methods have proven less effective on crocheted balls as compared to direct embroidery processes that allow for a much higher quality and higher resolution output.
[0020] Of further importance, but no less significant, is the fact that spherical crocheted object can be quite inexpensive to manufacture. This production process has solved the conundrum of utilizing the inexpensive crocheted ball for the purposes of carrying a high quality embroidered figure or message so that the ball may be utilized more effectively in publicizing an embroidered logo, name, motif, image, worded message, monogram, picture or illustration. Thus, the popular inexpensive crocheted ball can now be utilized as a higher quality medium for publicity purposes, advertising tools, corporate premiums, logo messages, or sports tool touting a team logo.
[0021] The invention calls for the modification of the fabrication of the crocheted ball so that it is capable to be sewn by high production embroidery machinery. After the embroidery is finished and the ball is completed according to the guidelines contained herein, the crocheted ball retains its round shape, its noteworthy durability and at the same time becomes a more useful advertising and promotion tool.
BRIEF DESCRIPTION OF DRAWINGS
[0022] For a fuller understanding of the invention and the process of producing a spherical crocheted object inclusive of embroidery steps, please refer to these drawings in which:
[0023] [0023]FIG. 1 illustrates a three dimensional view from an elevated and angled aspect of an unadorned ball in a typical size constructed using standard crocheted weaving;
[0024] [0024]FIG. 2 illustrates a bottom view of a crocheted ball that contains the figure of a star that has been embroidered directly onto the crocheted ball according to the present invention;
[0025] [0025]FIG. 3 illustrates a three dimensional view from an elevated and angled aspect of a ball containing a star in a contrasting color to that of the base color and that has been crocheted entirely within the ball according to the prior art;
[0026] [0026]FIG. 4 illustrates a bottom view of a representation of the crocheted initial disc showing individual crocheted stitch detail according to the present invention;
[0027] [0027]FIG. 5 illustrates a bottom view of a representation of the crocheted initial disc showing individual crocheted stitch detail after the placement of a representative embroidered star figure according to the present invention;
[0028] [0028]FIG. 6 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted initial disc showing individual crocheted stitch detail after the start of the cylindrical walls according to the present invention;
[0029] [0029]FIG. 7 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted ball construction showing individual crocheted stitch detail inclusive of nearly complete cylindrical walls according to the present invention; and
[0030] [0030]FIG. 8 illustrates a three dimensional view from an elevated and angled aspect of a representation of a crocheted ball construction showing individual crocheted stitch detail inclusive of cylindrical walls and woven top preceding final seamless closure according to the present invention.
DETAILED DESCRIPTION
[0031] The invention is embodied in the process by which a basic spherical crocheted object, such as a ball, FIG. 1, is fabricated. Additional fabrication steps transform this simply and inexpensively manufactured object, consisting of crocheted rows of thread 11 , into a more functional object for displaying a message, logo, words or logo.
[0032] [0032]FIG. 2 demonstrates the detail when applied to a crocheted ball according to the present invention. A star, 12 , is directly embroidered on top of the crocheted ball. Sewing of the embroidery is preferably a step separate and outside of the basic crocheted fabrication. The nature of the embroidery sewing disclosed herein possesses great detail advantages over crocheted objects. Although images, figures and logos fabricated on crocheted objects can be quite complicated and intricate, the fact remains that crocheted objects are restricted in the number of stitches per inch inherent in the manufacture of such objects. jects.
[0033] The limitations of the crocheted construction are further evident in FIG. 3 which shows a crocheted star, 14 , woven directly into a crocheted ball as is known in the art. This is the most common method of adding artwork or a logo to a crocheted object. It is apparent in FIG. 3 that the star does not elucidate a sharp image. The crocheted star is crude, “blocky,” and of minimal detail.
[0034] The embroidery sewing of the star 12 , in FIG. 2, on the other hand, elucidates a sharp image. One reason for the sharpness of the embroidery sewing is that the stitches in a crocheted object are large as compared to embroidery stitches. Crocheted thread typically contains more plies, or bundles, of heavier weight thread than embroidery thread. Crocheted thread must be thicker and more rigid to be more effectively used with a hooked crochet needle.
[0035] Crocheting, although appropriate for knitting sweaters and afghans, does not serve well for highly detailed tasks that call for a high amount of detail. On the other hand, embroidery, especially machined embroidery, can utilize many types of thread of a thinner and more supple variety with fewer plies. Embroidering equipment usually uses rayon or polyester thread, which is strong and thin, but can also use thread as fine as silk for highly detailed embroidery stitching.
[0036] In FIG. 3 the crocheted stitches contain typically, 10 stitches, or lines, per inch. By contrast, the embroidered stitches 13 , in FIG. 3, reveal lines of thread as depicted by the comb teeth-like edge between the black and white arms of the star figure and contain high resolution detail.
[0037] For every crocheted stitch, there are approximately 8 lines of embroidery. This equates to about 80 lines per inch, or 8 times the number of lines per inch as compared to the crocheted ball examples. Other crocheted objects, when compared to embroidery objects, educe similar quality comparisons.
[0038] Specific steps contained herein must be followed to permit the addition of the more detailed embroidery process upon spherical crocheted objects. In the drawings, the fabrication of a crocheted ball is being shown. An initial step in creating the ball is to establish a starting point, 16 , and crochet in a circular pattern as depicted in FIG. 4. Each individual crocheted stitch is represented by a cross hatched unit because thread used in a crocheted project typically contains multiple plies. In actuality, a crocheted stitch is less clear as the drawing representation in FIG. 4 because crochet thread tends to twist, fray and coalesce, becoming less distinct than the drawing depicts. The first three drawings are better representations of an actual crochet object which shows the thread as thick filaments.
[0039] As the crochet stitches are added, they are attached to each proximate stitch as shown in item 15 . Likewise, as the stitches are added in a circular motion, they are attached to the proximate row as shown in item 17 using the hooked crocheted sewing technique as depicted in item 18 . This technique is the origin for the durability of spherical crocheted objects. In addition, the crocheted object attains the ability to stretch and deform due to a general slackness in this type of multi-plied weaving.
[0040] An aspect of producing a spherical crocheted object is the creation of an “initial disc,” the product shown in FIG. 4. This initial disc is the base from which the embroidery is fashioned. It is imperative that the last stitch in the construction of the initial disc be tied off so that it does not come unwound. The initial disc must be substantially flat so that it can fit into the commercial embroidery machines for quick and effective stitching. Thus the stitches of the initial disc should not be tightened with each successive woven row. The stitching is created as one would create a flat weaving such as a placemat, coaster or other woven article with the stitches flaring out so that no shape is started. This differs from the current construction of spherical crocheted objects and is one important element of the invention.
[0041] The initial disc can be of any crocheted stitch combination upon which embroidery is placed. A solid color is a common choice although crocheted designs can still be used for the initial disc creation. Usually contrasting colors are chosen so the embroidery is visually recognizable and distinct. Any combination of thread colors can be chosen for the embroidery step. Many commercial embroidery machines can be loaded many different color threads so that an entire multi-color design can be done in a few seconds.
[0042] It is also important that a diameter of the initial disc is not larger than about 30% of the final circumference of the spherical crocheted object. Thus, for example, in a preferred embodiment, if the spherical crocheted object will have a final circumference of approximately 7.5″ inches, the initial disc must be no more than approximately 2.25″ inches in diameter when lying flat in order to work best for the embroidery. As the width of the initial disc exceeds 30%, the crocheted object will turn out less spherical, and will look oblong or misshapen. The diameter of the initial disc can be smaller than 30% of the final total circumference; however, a smaller initial disc reduces the area available for the embroidery. It is the upper threshold to which must be observed and adhered in the embodiment. Since the aim is to create an area upon which the higher quality embroidery may be sewn, and a discernible message may be advertised, the goal of maximizing the initial disc size is advised by keeping the diameter of the initial disc about 30% of the final circumference of the spherical crocheted object.
[0043] A next step of the invention is to utilize a commercial grade, high quality modern embroidery machine to directly embroider the logo on a substantially flat or the non-curved initial disc. Examples of commercial grade embroidery machines are the Tajima Bridge Type Cylindrical Frame Machine line, the SWF model 1508 multi-head embroidery machine or other equivalent commercial grade machines, either multi-head or single head. Other embroidery machines can be utilized for this step, but for quantity production, the multi-headed machines will function better than the single headed machines. Although machine embroidery is preferred, the embroidery can also be applied by hand. Some embroidery equipment is made for special functions and a wide range of options are available to individuals seeking to create artistically appealing thus effective logos or images.
[0044] It is, however, important that the embroidery does not exceed the diameter of the initial disc. In FIG. 5, the length of the embroidery is less than 2.25 inches because, in our drawing, this is the diameter of the initial disc. The needle of the embroidery machine should, in fact, remain at least one, preferably two embroidery rows away from the edge of the initial disc as depicted by the separation of the two pointers in item 19 . This way a solid and a well defined embroidery logo can be woven firmly onto the intial disc, such as the sample star, 12 . It is advised that no paper or fabric backing is used during the embroidery, which is a common step when embroidering with high quality embroidery machines. These backings tend to offer support to the embroidery whereas the article in question for this embroidery is a crocheted disc that needs to remain soft and pliable after the embroidery fabrication step. However, it is up to the manufacturer to determine the final “feel” of the spherical crocheted object. Selecting or not selecting an embroidery backing will affect this result.
[0045] The embroidery should then be finished off. Once disconnected from the embroidery machine, all loose threads should be tied off or cut on the front side of the “initial disc.” The back side the initial disc may contain loose and unfinished threads. This is acceptable because this portion of the initial disc will be located on the inside of a spherical crocheted object. Although not important to the embodiment, it may be the choice of the manufacturer to trim the extra threads to avoid difficulties in the later fabrication steps, although the economy and complexity of the project may influence this decision. With the completion of the embroidery, the initial disc is ready for the next step of the weaving process.
[0046] The next step of the process of an embodiment is illustrated in FIG. 6 and performed on our initial disc. The final stitch that had been tied off is untied and the crochet process continues, only this time the rows are tightened so that the row of stitches bends upward, item 22 , starting at point 21 . Each successive row of crocheted stitches are woven in a spiral fashion flaring out from the initial disc, 20 , and each stitch is hooked into the row beneath it as with the initial disc construction.
[0047] This is a crucial point in the fabrication process of the embodiment. Since the initial disc is flat, the ball must be woven so that it forms a spherical object or ball, and to accomplish this, each stitch must be pulled upward as woven at 23 , and tightened before they are hooked together. The loose threads, 24 and 25 , are crocheted and build upon the rows consecutively. If the color of the crocheted ball is to be solid, then the continuation of the weaving should include the identical color thread; if additional designs are to be included in the final spherical crocheted object, this is a logical point to initiate a thread color change for the creation of a crocheted design on the object.
[0048] As successive rows are added to the previous row, a cylinder takes shape as shown in the FIG. 7, which looks somewhat like a cylindrical wall with successive and stacked rows of crocheted stitches, 35 through 43 . As noted in FIG. 7, the construction of the cylindrical wall is akin to the “side” of the crocheted ball and the bottom, the initial disc, being the initiation point and center that contains the embroidered figure. The top will be the final termination and closure point of the ball. Thus, the ball has a top and bottom for the purposes of our embodiment description and the cylindrical wall will have a center, or point of maximum diameter, which in our drawing lies between rows 38 and 39 because there is an even number of rows. For a construction with an odd number of rows, there would be one row designated as the row of maximum diameter, or center.
[0049] A crucial aspect at this important construction stage of an embodiment is in calculating and duplicating the number of stitches per row. The number of stitches per row will vary depending on the size of the initial disc which, as mentioned before, is determined by the desired size of the embroidery logo and the desired size of the crocheted ball. Independent of the ball size, a formula can be utilized for the purposes of the embodiment that will direct the manufacturer to make a crocheted ball that will retain its all important round shape.
[0050] In the first row of the crocheted cylindrical wall, it is important to note the number of stitches and abide by some conditions when building upon the cylindrical wall rows. First, the number of stitches should never be reduced when building up the cylindrical walls. The counted stitches may be kept the same or increased slightly to the point that which the maximum diameter of the ball is attained. Reducing the stitches in the successive rows will cause the ball to be misshapen, an undesired result. In FIG. 6, the successive rows contain 60 stitches each. All the rows in the cylindrical walls contain 60 stitches. If rows 35 through 38 contained less stitches than the previous, then the ball may end up misshapen. However, if row 35 contained 61 stitches and row 36 contained 62 stitches, this would be an acceptable iteration for this construction.
[0051] The point that which the maximum diameter of the spherical crocheted object is attained is another calculation that is important in the construction in accordance with our embodiment. It has been found that to make a spherical crocheted object like a ball, the cylindrical sides of the ball should have a number of rows that is between around 36% and around 46% of the total number of rows in the construction of the ball. In our drawing, FIG. 5 contains 10 crocheted rows in the cylindrical wall of this crocheted ball which is approximately 38.5% of the total number of rows of this ball construction. In this drawing and in this sample, there are 10 rows on the cylindrical wall. In our drawing it can be determined that the center, or diameter, of the ball is between rows 38 and 39 from the bottom of the cylindrical wall. However, this value can be determined in advance by calculating the midway point in the cylindrical wall using our estimate of acceptable wall size, which can be estimated in advance to be between rows 38 and 39 .
[0052] Next, once the maximum diameter of the ball is attained, it is acceptable to reduce the number of stitches per row, for rows 39 through 43 ; or to maintain the same number of stitches in the ball, in order to maintain a round ball. It is not recommended to increase the number of stitches or again a misshapen ball will result. In large scale production, it may be unreasonable to count stitches, so maintaining the same number of stitches for each row in the middle is an acceptable and advisable practice. Once the ball is complete, due to the nature of crocheted stitches, the threads will stretch giving the ball its desired round shape.
[0053] It must be noted that the construction of a spherical crocheted object is not a precise science and variations will arise. Variables include the thickness of the thread, size of the stitches and slackness of the stitches. In addition, for the construction of a spherical crocheted object, there is often no definite demarcation as to where the cylindrical wall starts and the bottom construction ends, particularly once the first row in the cylindrical wall is begun and tightened, which tends to warp the entire construction upwards, forcing it into the shape of a ball. Thus, we have supplied relative percentages for the purposes of calculating the proper construction of the embroidered crocheted ball; however, these values are quite close and have been determined over repeated testing and constructions.
[0054] In our embodiment, the point at which it can be determined that the cylindrical walls have ended (FIG. 7, item 44 and 45 ) we complete the top of the embodiment. Taking the remaining loose threads, 46 , we start to crochet the top of the ball, bending them as stitches are added as shown in FIG. 8. This crocheting step will generally match the bottom initial disc, 20 , of the crocheted ball (in terms of size and number of rows) which contains the embroidered portion of the construction. The embroidery portion can not be viewed in FIG. 8 because it is on the bottom of the ball.
[0055] It is important to leave a small hole, 28 , in the top of a spherical crocheted object. This hole is where a filling is inserted and a final closure is made. The ball is typically filled with plastic pellets or some other desired filling. The volume percentage of the filling will determine how slack or firm the ball feels. A large number of manufacturers that utilize the crocheted ball for the game of footbag use plastic pellet filling of approximate 2 millimeters diameter in size, of varying shapes, and choose to loosely fill the crocheted ball with from 40 to 75 fill percentage to give the ball the low bounce characteristics desired by many of the players of the game. Manufacturers of crocheted juggling balls tend to fill the crocheted ball with 100 percent fill to give the ball a harder feel and an easier grip which is more suitable for their sport. Many other fill types and combinations exist. In our embodiment, filling and closure are all part of the normal manufacture found in the production of crocheted balls. Note in FIG. 8 that a hole has been left with two loose threads, 24 and 25 . Commonly the extra thread is left to perform the final closure after filling. The final closure is done using the crochet hooked needle and tied off to seal the construction.
[0056] Due to the pliant and soft nature of the thread materials such as those used in the fabrication of spherical crocheted objects, once completed, the object will lose the cylindrical shape and transform into the shape of a ball. This transformation can be accentuated by compressing or kneading the ball under pressure which will stretch out the stitches to give the crocheted ball a more round appearance, and will enhance the playability features desired in a ball of this type.
[0057] By following the construction process laid forth herein, a spherical crocheted object will have been successfully created that contains an embroidered logo and that can be duplicated on a large scale.
|
A spherical crocheted object includes a portion that contains high quality embroidery and is made beginning with a fabric piece called an initial disc. By initially knitting the spherical crocheted object into a flat, round disc of specific and limited dimensions, this initial disc is created for the introduction of an external embroidery process. The crocheted initial disc is tied off to maintain durability during the embroidery step, which is usually performed on specialized embroidery equipment. Thereafter, by vigilantly following specific construction techniques, a ball will be produced that retains its spherical shape resulting in an end product with characteristics similar to that of a spherical crocheted object that does not contain embroidery.
| 3
|
BACKGROUND OF THE INVENTION
The invention relates to a driving belt for use in a continuously variable transmission comprising two V-shaped pulleys, which driving belt comprises a carrier consisting of two endless band packages lying side by side, on which transverse elements are disposed, wherein each transverse element includes two recesses positioned opposite each other for receiving the band packages, so that a first part of the transverse element extends under said band packages, a second part of the transverse element is positioned between said band packages and a third part of the transverse element extends above said band packages, wherein the front side of the transverse element includes a projection which can mate with a recess in the adjacent transverse element.
BACKGROUND OF THE RELATED ART
Such a driving belt is known from EP-A-0 014 013. The mating projection and recess ensure that transverse elements located adjacently to each other are correctly positioned with respect to each other during operation of the driving belt, especially in the straight part of the driving belt.
Each time a direction is described in relation to a transverse element, it is assumed that the transverse element occupies an upright position, as is shown in front elevation in FIG. 2 . In said figure, the longitudinal direction is the direction perpendicularly to the plane of the figure.
The provision of the projection, and of the corresponding recess that is located on the other side of the transverse element, takes place through deformation of the material, wherein a stamp forms the recess by moving into the material. This causes the material to be deformed to such an extent that said projection is formed on the other side of the transverse element.
This is a relatively difficult operation. It would be easier to realise a profile wherein the projection and the recess extend in horizontal direction. Such a profile can be formed by means of a rolling operation, for example, or by a grinding operation. When the transverse elements are cut from a strip of material, said strip of material can be provided with such a profile in advance.
Although a projection/recess, which extends in horizontal direction, has advantages when forming the same, it has become apparent in practice that such a projection/recess is not always satisfactory.
A projection and a recess which extend in horizontal direction have a surface which is substantially made up of a series of horizontal lines extending in transverse direction with respect to the driving belt.
SUMMARY OF THE INVENTION
The object of the invention is to provide an improved driving belt, which driving belt is easier to manufacture and/or which operates more efficiently and/or more reliable.
Another object of the invention is to create a possibility to make the third part of the transverse element smaller, and thus lighter.
In order to accomplish that objective, said projection extends in horizontal direction, and wherein the rear side of the transverse element includes a recess which likewise extends in horizontal direction, wherein said projection and said recess are at least partially formed in the second part of the transverse element.
Said projection may be straight, but also elliptic or barrel-shaped.
By forming the projection at least partially in the second part of the transverse element, the length of the projection (its dimension in horizontal direction) at least at the bottom side of the projection is limited to the width of the aforesaid second part. In practice it has become apparent that this enables the driving belt to function better than in the situation wherein the projection extends over the entire width of the transverse element, that is, wherein the projection is formed in a part of the transverse element that is considerably wider than said second part.
From U.S. Pat. No. 3,949,621 it is known per se to form the projection in the second part of the transverse element. The projection that is used therein, however, is a projection which is round when seen in front view, that is, said projection does not extend in horizontal direction. The consequence is, therefore, that the second part must have a considerable width in order to make it possible to form the projection therein. The fact of the matter is that sufficient material must be present around the projection to be formed in order to enable correct deformation of material upon formation of the projection.
Preferably, said projection and said recess are present in large part in the second part of the transverse element, and more preferably said projection and said recess are mainly present in the second part of the transverse element. Owing to the limited length (in horizontal direction) of the projection and the recess, the connection that is thus obtained between transverse elements positioned adjacently to each other appears to function well in practice.
Preferably, said projection and said recess extend in transverse direction over the entire area of the transverse element between the two recesses.
Preferably, said projection is disposed some distance above the tilting line, which is the horizontally extending area of the surface of the transverse element that is constantly in contact with the adjacent transverse element. The tilting line is located under the band packages, and it is formed by a rounded corner in the surface of the transverse element.
Preferably, said projection is spaced from the tilting line by a distance, which is smaller than the smallest vertical dimension of the recess.
In one embodiment, the surface of the projection and of the recess comprises parts which extend at an angle to a horizontal line in the plane in which the band packages lie, and which extends perpendicularly to the direction of the driving belt. When such a part of the projection mates with a corresponding part of the recess, it is possible to reduce the extent to which two abutting transverse elements can move in horizontal direction relative to each other. In that case the surface of the projection and the recess in not entirely made up of a collection of horizontal lines, but it comprises a part that is different therefrom. Preferably, such a part of the projection is in the form of a recess in the surface, which recess preferably extends in vertical direction, as will be explained in more detail by means of an exemplary embodiment.
In another preferred embodiment, said third part of the transverse element comprises the aforesaid parts, which extend at an angle to the aforesaid line.
Preferably, the transverse element is made from a strip of material by means of a cutting operation, and the edges of the transverse element have been deburred and/or been rounded by means of a tumbling operation, wherein the surface of the transverse elements is worked with hard elements.
The invention furthermore relates to a transverse element for use in a driving belt for a continuously variable transmission comprising two V-shaped pulleys, which transverse element includes two recesses positioned opposite each other for receiving band packages forming a carrier, so that a first part of the transverse element extends under said band packages, a second part of the transverse element is positioned between said band packages and a third part of the transverse element extends above said band packages, wherein each recess includes an inside surface facing towards the band package, wherein said projection extends in horizontal direction, and wherein the rear side of the transverse element includes a recess which likewise extends in horizontal direction, wherein said projection and said recess are at least partially formed in the second part of the transverse element.
In order to explain the invention more fully, an exemplary embodiment of a driving belt will be described hereafter with reference to the drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side view of a driving belt;
FIG. 2 is a front view of a transverse element;
FIG. 3 is a side view of the transverse element;
FIG. 4 is a rear view of the transverse element; and
FIG. 5 is a view of a detail of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The schematic illustration of FIG. 1 shows the driving belt 1 , which runs over two pulleys 2 , 3 . In the illustrated situation, the left-hand pulley 2 rotates faster than the right-hand pulley 3 . By changing the mutual distance between the two parts of which each pulley 2 , 3 consists, it is possible to change the radius of the driving belt 1 at the location of pulley 2 , 3 , as a result of which the difference in speed between the two pulleys 2 , 3 can be varied as desired. This is a well-known way of varying a difference in rotational speed between two shafts.
The driving belt 1 , which is shown in side elevation in FIG. 1 , is built up of a plurality of transverse elements 4 (four of which are shown in FIG. 1 ) and two band packages 5 , 6 , one of which is indicated by the shaded part in the figure. Both the transverse elements 4 and the bands of the band packages 5 , 6 are made of a metal. The transverse elements 4 can move freely in the longitudinal direction of the band packages 5 , 6 , so that when a force is being transmitted between pulleys 2 , 3 , said force is transmitted by the transverse elements 4 pressing one against another. The band packages guide the transverse elements 4 thereby.
In the illustrated embodiment, each band package 5 , 6 consists of five bands, as is shown in FIG. 2 . In practice, a band package 5 , 6 frequently comprises more bands, for example ten. In FIG. 2 , the thickness of the band package 6 is indicated at T and the width is indicated at W. The thickness of a band is 0.2 mm, for example, with the width being 7 mm.
It will be apparent that the band packages 5 , 6 cannot move out laterally, because parts of the pulleys 2 , 3 are positioned on either side of the driving belt 1 . From the figures it is apparent that the shape of transverse elements 4 has been selected so that said transverse elements are retained in position by the band packages 5 , 6 . Said shape comprises two recesses 7 , 8 , in which the band packages 5 , 6 are accommodated.
Transverse element 4 consists of a first part 11 , which extends under band packages 5 , 6 , a second part 12 , which is located between band packages 5 , 6 , and a third part 13 , which extends above band packages 5 , 6 .
The rear side of transverse element 4 (shown in FIG. 4 ) is substantially flat, and on its front side (shown in FIG. 2 ), transverse element 4 exhibits a so-called tilting line 18 . The part of transverse element 4 above tilting line 18 has a substantially constant thickness, seen in side elevation ( FIG. 3 ), whilst the first part 11 under tilting line 18 tapers off in downward direction. Tilting line 18 is in fact formed by a slightly rounded strip on the front side of transverse element 4 , for example by an edge having a radius of curvature of 6 mm. Tilting line 18 is in contact with the rear side of the adjacent transverse element 4 , both in the straight parts of driving belt 1 and in the curved parts thereof.
Below tilting line 18 , first part 11 tapers off to an edge 26 extending in horizontal direction. First part 11 below edge 26 exhibits a constant thickness, which is about 0.1 mm less than the thickness of transverse element 4 just above edge 26 .
As can be seen in particular in FIG. 3 , the second part 12 of transverse element 4 is shifted to the left (in FIG. 3 ), as a result of which a projection 14 is formed on the front side of transverse element 4 , whilst a recess 15 is present on the rear side. As is apparent from FIGS. 2 and 4 , projection 14 and recess 15 extend in horizontal direction over the entire second part 12 of transverse element 4 .
Projection 14 and recess 15 interlock in the straight parts of driving belt 1 , as a result of which two abutting transverse elements 4 are prevented from shifting relative to each other.
As FIG. 2 shows, projection 14 is centrally provided with a recessed part 16 , and FIG. 4 shows that recess 15 is centrally provided with a projecting part 17 . In this manner, the surfaces of projection 14 and recess 15 include parts which extend at an angle to a horizontal line in the plane in which band packages 5 , 6 lie, and which extends perpendicularly to the direction of driving belt 1 .
In a straight part of the driving belt 1 , the projecting part 17 comes into engagement with the recessed part 16 , so that relative movement of two transverse elements 4 lying adjacently to each other is reduced or prevented altogether as a result of said parts including an angle coming into contact with each other.
As appears from the figures, projection 14 and recess 15 are located entirely in the second part 12 of transverse element 4 , as a result of which their dimension in transverse direction (horizontal direction) is limited.
Each of the recesses 7 , 8 is bounded by an inside surface that is formed by portions of first part 11 , second part 12 and third part 13 of transverse element 4 . Said portions are indicated by numerals 21 , 22 and 23 , respectively, in FIG. 5 .
FIG. 5 is a detailed view of the shape of recess 7 . Inside portion 21 includes a straight or slightly curved part at the location of first part 11 of transverse element 4 , which part comes into contact with the band package 5 . Said part merges with a convex portion thereof having a radius R 2 into a concave portion of the inside surface having a radius R 1 at the location where portion 21 of the inside surface merges with portion 22 .
In the illustrated embodiment, R 1 equals approximately half the distance B, which distance is the largest vertical dimension of recess 7 near the second part 12 of transverse element 4 . The inside surface 22 at the location of second part 12 may exhibit a vertical, straight portion at the location of second part 12 , but in the present embodiment said portion 22 of the inside surface is curved in its entirety, and that practically in the form of an arc having a radius R 1 .
In FIG. 5 , letter A indicates the smallest vertical dimension of recess 7 , which dimension is preferably larger than 80% of the largest vertical dimension B of recess 7 near the second part 12 of transverse element 4 .
FIG. 5 shows angle a, which is the angle which the portion 22 of the inside surface that is formed by the second part 12 of transverse element 4 includes near the underside of band packages 5 , 6 with the plane in which band packages 5 , 6 lie. As is shown in FIG. 5 , said angle is an acute angle, preferably of less than 85°.
In practice it has become apparent that the convex curvature having radius R 2 must be sufficiently large, for example 0.4 mm or more. When the radius R 2 is not large enough, damage to the innermost band of the band package 5 , 6 may ensue. Also the radius R 1 of the adjoining concave curvature must be sufficiently large. It has become apparent that when R 1 is larger than 0.7 mm, the risk of fracture of the transverse element 4 is reduced to such an extent that the first part 11 of 64 may be smaller, that is, have less mass. It is possible thereby to reduce the distance between the lower edge 24 of transverse element 4 and the inside surface 21 , 22 at the location of the aforesaid curvature significantly, that is, said distance can be much smaller than the height H of the surface 25 of transverse element 4 that comes into contact with pulleys 2 , 3 . Said reduction contributes to a satisfactory dynamic behaviour of the transverse element. Preferably, the lower edge 24 is concave over substantially its entire length. The above-described embodiment is merely an exemplary embodiment, many other embodiments are possible.
|
A driving belt for use in a continuously variable transmission comprising two V-shaped pulleys, which driving belt comprises a carrier consisting of two endless band packages lying side by side, on which transverse elements are disposed. Each transverse element includes two recesses positioned opposite each other for receiving the band packages, wherein a part of the transverse element is positioned between said band packages. The front side of the transverse element includes a projection, which can mate with a recess in the adjacent transverse element. Said projection and said recess are at least partially formed in the aforesaid part of the transverse element.
| 5
|
This is a divisional of application Ser. No. 08/749,480 filed on Nov. 13, 1996, now U.S. Pat. No. 5,703,734, issued Dec. 30, 1997 which is a continuation of application Ser. No. 08/321,935 filed on Oct. 12, 1994, now abandoned.
FIELD OF THE INVENTION
The present invention pertains to the field of disk drives which are also called direct access storage devices (DASD).
More particularly, this invention pertains to a shock protection apparatus for a disk drive or direct access storage device (DASD).
BACKGROUND OF THE INVENTION
One of the key components of a computer system is a place to store data. Typically computer systems employ a number of storage means to store data for use by a typical computer system. One of the places where a computer can store data is in a disk drive which is also called a direct access storage device.
A disk drive or direct access storage device includes several disks which look similar to 45 rpm records used on a record player or compact disks which are used in a CD player. The disks are stacked on a spindle, much like several 45 rpm records awaiting to be played. In a disk drive, however, the disks are mounted to the spindle and spaced apart so that the separate disks do not touch each other.
The surface of each disk is uniform in appearance. However, in actuality, each of the surfaces is divided into portions where data is stored. There are a number of tracks situated in concentric circles like rings on a tree. Compact disks have tracks as do the disks in a disk drive. The tracks in either the disk drive or the compact disk essentially replace the grooves in a 45 rpm record. Each track in a disk drive is further subdivided into a number of sectors which is essentially just one piece of the track.
Disks in a disk drive are made of a variety of materials. Most commonly, each other the disks used in rotating magnetic systems is made of a substrate of metal, ceramic, glass or plastic with a very thin magnetizable layer on either side of the substrate. Such a disk is used in magnetic, and magneto-optical storage. Storage of data on such a disk entails magnetizing portions of the disk in a pattern which represents the data. Other disks, such as those used in CD's, are plastic. Data, such as songs, is stored using a laser to place pits in the media. A laser is used to read the data from the disk.
As mentioned above, to store data on a disk used in a rotating magnetic system, the disk is magnetized. In order to magnetize the surface of a disk, a small ceramic block known as a slider which contains at least one magnetic transducer known as a read/write head is passed over the surface of the disk. Some ceramic blocks contain a separate read head and a separate write head. The separate read head can be a magnetoresistive head which is also known as an MR head. The ceramic block is flown at a height of approximately six millionths of an inch or less from the surface of the disk and is flown over the track as the transducing head is energized to various states causing the track below to be magnetized to represent the data to be stored. Some systems now also use near contact recording where the slider essentially rides on a layer of liquid lubricant which is on the surface of the disk. With near contact recording, the ceramic block passes even closer to the disk.
To retrieve data stored on a magnetic disk, the ceramic block or slider containing the transducing head is passed over the disk. The magnetized portions of the disk generate a signal in the transducer or read head. By looking at output from the transducer or read head, the data can be reconstructed and then used by the computer system.
Like a record, both sides of a disk are generally used to store data or other information necessary for the operation of the disk drive. Since the disks are held in a stack and are spaced apart from one another, both the top and the bottom surface of each disk in the stack of disks has its own slider and transducing head. This arrangement is comparable to having a stereo that could be ready to play both sides of a record at anytime. Each side would have a stylus which played the particular side of the record.
Disk drives also have something that compares to the tone arm of a stereo record player. The tone arm of a disk drive, termed an actuator arm, holds all the sliders and their associated transducing heads, one head for each surface of each disk supported in a structure that looks like a comb at one end. The structure is also commonly called an E block. A portion of metal, known as a suspension, connects the sliders to the E block. At the other end of the actuator is a coil which makes up a portion of an voice coil motor used to move the actuator. The entire assembly is commonly referred to as an actuator assembly.
Like a tone arm, the actuator arms rotate so that the transducers within the sliders, which are attached to the actuator arm can be moved to locations over various tracks on the disk. In this way, the transducing heads can be used to magnetize the surface of the disk in a pattern representing the data at one of several track locations or used to detect the magnetized pattern on one of the tracks of a disk. Actuators such as the ones described above are common to any type of disk drive whether its magnetic, magneto-optical or optical.
Disk drives, like all other electronic devices, are becoming smaller and smaller. These smaller drives are being used in portable laptop computers and notebook computers which are also very small. These smaller drives can be removed from these smaller computers. Some of these smaller drives have the dimensions of a thick plastic credit card and can literally be carried around in a person's shirt pocket. The dimensions of these drives as well as other parameters are set by an industry standard called the Personal Computer Memory Card Industry Association, also known as PCMCIA. Due to the removability and small size, these drives are more susceptible to being dropped. The PCMCIA standard includes a series of drop tests that must be passed.
PCMCIA standard handling specifications require that products (including disk drives) be able to withstand drops of 30 inches onto very hard vinyl clad cement floor surface. This drop converts a significant amount of potential energy into kinetic energy. Accordingly, due to the reduced size of the disk drive, the PCMCIA DASD is more delicate and may be more susceptible to damage upon impact. The abrupt stop upon impact converts the kinetic energy into very high deceleration forces which may exceed the forces which the PCMCIA DASD components may accommodate.
Passing the PCMCIA standard requires either increasing the sturdiness of the internal components, or reducing the deceleration forces during impact to a point below critical acceleration levels for the components of the DASD. Increasing the sturdiness of the internal components in is more or less thwarted by the fact that the size of the devices has been reduced such that maintaining significant strength within some components is no longer possible. The remaining approach is to provide shock protection.
Although there are many possible sources for impacts to a disk drive, there seem to be two sources of impact which are more likely. The use of the disk drives or DASD in laptop and notebook size computers suggests a high probability of DASD impacts as a result of the computer being dropped or mishandled. The impacts also can result from any rough handling of the disk drive itself after it has been removed or before it has been placed into the slot in the computer. One example might be when the disk drive has been removed from the computer and placed in a shirt pocket of the user. When the user bends over to pick something up, the disk drive could fall onto the floor. Another example would be dropping a disk drive out of an executive's brief case or even fumbling a disk drive on a plane when trying to change from one hard disk drive to another disk drive. The impacts that occur to the disk drive when not installed in a computer, as a general rule, will probably be more serious than the impacts that result while the drive is housed within the computer.
Two types of impacts to an uninstalled disk drive seem to be particularly devastating. The first is when the disk drive falls on a corner of the disk drive. The second is known as a flat drop when a disk drive falls squarely on the entire base or cover of the disk drive. Thus, what is needed is a disk drive designed such that it can withstand the shock test set froth in the PCMCIA standard and more particularly designed to withstand the shock of impact caused by a drop on the corner of the drive and by a flat drop onto one of the major surfaces of the drive.
Another need for disk drives is the ability to seal the juncture between the base and the cover of the drive. The environment inside the disk drive must be very clean as the transducer is typically flown within 2 to 3 microinches of the surface of the disk. At such low heights, a particle of smoke from a cigarette is a major obstacle which would cause what is known as a "head crash" and would also result in a loss of data on the surface of the disk. A loss of data is a major concern to manufacturers of disk drives as it is a major concern to customers or users of disk drives.
To prevent contamination, most manufacturers provide tight seals around the joints in the disk drive and provide a filter to remove large particles and organic contaminants from any incoming air. The tight seals prevent unfiltered incoming air from entering where the seals are located and require the incoming air to pass through the filtered opening in the disk drive. It is important to also provide a good seal that is not easily removed from an assembled disk drive. If the seal can be removed, then the possibility occurs where unfiltered air can enter the disk drive. Also, the seal should be compliant to not only provide for a good seal between the various parts of the disk drive but also to provide for some shock absorption between the base and the cover of the drive.
It would also enhance manufacturability if the shock absorption system and the seal or gasket was one unitary piece which could be laid down on the base in a top down assembly of the disk drive.
Since these small disk drives are so susceptible to shock loading or impact, either while installed in a computer or when outside of the computer, it would also be advantageous to have a way to detect when a drive has undergone a shock loading or impact event of a selected magnitude. This would be advantageous since a drive may still work after undergoing such a shock and a user could then copy the data on the disk to assure against data loss, before failure occurred. Furthermore, a user who was purchasing these small drives would know if the disk drive has undergone such an impact and could refuse the purchase. It is thought that these drives will be very inexpensive and readily available in computer stores. With a visible shock detector, a purchaser could be assured that the drive had not already undergone some sort of shock during shipment The store purchasing the drives would also be assured that the shipment was good and that there would not be an inordinate amount of returns of the drives purchased for resale. If purchased via mail order, the purchaser could also check the drive to assure that the drive had not been mishandled during shipment. If it had it could be returned and the company selling the drive could collect the cost of the drive from the shipper.
Thus, what is needed is a shock absorbing system for a disk drive that can pass the tests set forth in the PCMCIA standard and which can withstand drops on the corner of the disk drive as well as flat drops which are substantially along an entire edge or along an entire flat surface on the disk drive. What is also needed is a seal or gasket that is integral with the shock absorber and which can be placed on the base or cover easily to enhance manufacturability of the disk drive. In addition, the gasket and bumper should be locked into place so that the seal is not broken or so that the bumper does not separate from the disk drive during a shock. This mitigates the problems which could arise from taking in unfiltered air and from subsequent shocks. Also, there is a need for a way to indicate when such a disk drive has undergone shock loading or an impact of a certain level. Preferably, the indicator should be clearly visible from the exterior of the drive.
SUMMARY OF THE INVENTION
Disclosed is a combination shock absorber and gasket seal capable of passing the impact tests set forth in the PCMCIA. The shock absorber and gasket seal is also a one-piece unit which aids in the manufacturability of the disk drive. The one-piece shock absorber and gasket seal also includes a mechanism to maintain the shock absorber and gasket in place during a shock. The mechanism to maintain the position of the shock absorber and gasket has several different features at different positions about the juncture between the base of the disk drive and the cover. The gasket has cutouts therein to accommodate the disk and allow enough space to let the body yield elastically somewhat without contacting the disk. The mechanism to maintain the position of the shock absorber is different in this location. The one-piece shock absorber and gasket seal extends around more than three sides of the perimeter of the disk drive enclosure. In one preferred embodiment, the one-piece shock absorber and gasket seal extends to the full height of the disk drive. In some places there are ribs which extend beyond the height of the disk drive so as to provide shock absorbing capability in the event of a flat drop. In another preferred embodiment of the shock absorbing system, there are a plurality of rotatable blocks of shock absorbing material attached to the disk drive. The blocks are rectangular in cross section and can be rotated out to a position where their height is greater than the height of the drive. When a user removes the drive from a system, the blocks can be so rotated so that in the event of a flat drop, the drives will land on the rotatable blocks rather than on the flat cover or base of the drive. Also disclosed is a shock indicator which is visible from the exterior of the drive. When a drive has undergone a shock of a selected magnitude, the indicator will change color thereby warning the user that the disk drive has undergone a shock above a selected level.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, reference can be made to the accompanying drawings, in which:
FIG. 1 is an exploded view of a disk drive.
FIG. 2 is an exploded view of a disk drive which shows the integral gasket and shock absorbing bumper. Several of the components of the disk drive shown in FIG. 1 are eliminated for the sake of clarity.
FIG. 3 is a cross-sectional view of the shock absorbing bumper in an assembled drive.
FIG. 4 is a top cut away view of the integral shock absorbing bumper and gasket near the disk of the disk drive.
FIG. 5 is a cross-sectional view of the shock absorbing bumper in an assembled drive in the area near the disk of the disk drive.
FIG. 6 is a cross-sectional view of the shock absorbing bumper in an assembled drive in the area near the end of the disk having the connector.
FIG. 7 is an isometric cut-away view of the end of the disk drive with the connector which shows the locking features on the drive and corresponding features on the one-piece shock absorber and gasket seal.
FIG. 8 is an isometric view of the assembled disk drive which uses the combination shock absorber and gasket seal.
FIG. 9 is an isometric view of a drive having elastomeric pads that extend above the height of the disk drive.
FIG. 10 is an isometric view of a second preferred embodiment of the shock absorbing system for a disk drive.
FIG. 11 is an isometric view of a second preferred embodiment of the frame and connector shroud of the second preferred embodiment of the shock absorbing system for a disk drive.
FIG. 12 is a top view of the corner of a disk drive shown in FIGS. 10 and 11 which shows how the corner withstands an impact load to the corner.
FIGS. 13A, 13B, 13C and 13D are side views of a second embodiment of the drive at sequential times during the insertion of the drive into a drive bay.
FIG. 14 is a top view of the cover of a disk drive which includes a covered window where a shock sensor can be viewed.
FIG. 15 is a view detailing the shock sensor shown in FIG. 14.
FIG. 16 is a cut-away side view of an edge of using an elastomeric pad.
These drawings are not intended as a definition of the invention but are provided solely for the purpose of illustrating the preferred embodiments of the invention described below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention described in this application is useful with all mechanical configurations of disk drives or direct access storage devices ("DASD") having either rotary or linear actuation. FIG. 1 is an exploded view of a disk drive 10 having a rotary actuator. The disk drive 10 includes a housing or base 12, and a cover 14 for the housing or base. The housing or base 12 and cover 14 form a disk enclosure. Rotatably attached to the housing or base 12 on an actuator shaft 18 is an actuator assembly 20. The actuator assembly 20 includes a comb-like structure 22 having a plurality of arms 23. Attached to the separate arms 23 on the comb 22, are load beams or load springs 24. Attached at the end of each load spring 24 is a slider 26 which carries a magnetic transducer (not shown). The slider 26 with the transducer form what is many times called the head. It should be noted that many sliders have one transducer. It should also be noted that this invention is equally applicable to sliders having more than one transducer, such as what is referred to as an MR or magneto resistive head in which one transducer is used only for reading and another is used for writing. Many sliders 26, which employ thin film transducers, have more than one thin film transducer but generally use only one of the thin film transducers. On the end of the actuator arm assembly 20 opposite the load springs 24 and the sliders 26 is a voice coil 28.
Attached within the housing 12 is a pair of magnets 30. The pair of magnets 30 and the voice coil 28 are key parts of a voice coil motor which applies a force to the actuator assembly 20 to rotate it about the actuator shaft 18. Also mounted to the housing 12 is a spindle motor 32. The spindle motor 32 includes a rotating portion called the spindle hub 33. In FIG. 1, a single disk 34 is attached to the spindle hub 33. In other disk drives a number of disks may be attached to the hub. Also disclosed is an expanded flex cable or regular printed circuit card 67 which includes many of the electrical components for performing many of the electrical operations of the disk drive. The expanded flex cable or printed circuit card 67 is positioned inside the disk enclosure. The components on the expanded flex cable or printed circuit card 67 are treated to substantially reduce or eliminate outgassing within the disk enclosure. The invention described herein is equally applicable to disk drives have a number of disks attached to the hub of the spindle motor. Also attached to the base or housing 12 is a ramp structure 36 for loading and unloading the slider 26.
FIG. 2 is an isometric view of the disk drive 10 with many of the mechanical assemblies of FIG. 1 removed for the sake of clarity. FIG. 2 adds a combination shock absorbing bumper and gasket seal 40. The combination shock absorbing bumper and gasket seal 40 includes an elastomeric bumper 42 and a gasket seal portion 44. The gasket seal portion includes locking tabs 46' and 46" which keep the combination shock absorbing bumper and gasket seal 40 in position during a shock loading event or impact, or in the event of rough handling. The locking tabs 46' and 46" occur on three sides of the disk drive 10. There are actually two types of locking tabs 46' and 46" which will be discussed with the cross-sectional views of FIGS. 3 and 5 below. The combination shock absorbing bumper and gasket seal 40 also has special locking features at or near one end of the drive which will be further detailed in the discussion of FIG. 6. The gasket seal portion 44 (shown in FIGS. 2-5) has a pair of cutouts 48 therein which provide disk 34 with enough clearance to allow the disk 34 to rotate and also to allow for a small amount of clearance during an impact. The combination shock absorbing bumper and gasket seal 40 also includes a connector portion 54 which makes the gasket seal portion 44 extend around a sealed disk enclosure 56 of the drive 10. It should be noted that the combination shock absorbing bumper and gasket seal 40 is a one-piece assembly which facilitates the manufacture of the drive 10. Since the combination shock absorbing bumper and gasket seal 40 is one piece, the combination shock absorbing bumper and gasket seal 40 merely has to be correctly positioned on top of the base 12 during a top down manufacturing procedure where the base 12 is laid down and components are attached to it. After placing the combination shock absorbing bumper and gasket seal 40 on the edge of the base 12, the components are attached to the base 12 and the last step of attaching the cover 14 to the base seals the disk drive to form the sealed disk enclosure 56 and lock the combination shock absorbing bumper and gasket seal 40 in place.
Now turning briefly to FIGS. 6-8, it can be seen that the disk drive 10 includes a connector 60 located at one end of the disk drive 10. Returning to FIGS. 1 and 2, the disk drive has two shorter sides which are a connector end 62 and short side 64. The disk drive 10 also has two longer sides which are substantially identical and not thought to need specific element numbers.
FIG. 3 shows a cross sectional view of the short side 64 of the drive 10. In FIG. 3 the combination shock absorbing bumper and gasket seal 40 is shown in its assembled position between the base 12 and the cover 14. When assembled the cover 14, base 12 and combination bumper and gasket 40 form a sealed disk enclosure 56. The elastomeric bumper portion 42 of the combination bumper and gasket seal 40 extends to the full height, h, of the disk drive 10. The full height, h, of the disk drive 10 includes the thickness of the cover 14, the thickness of the base 12 and the thickness of the gasket seal portion 44 which is sandwiched between the base 12 and the cover 14. The combination bumper and gasket seal 40 also includes locking tab 46' which is located on the end of the gasket seal portion 44 extending into the sealed disk enclosure 56. The locking tab 46' is thicker than the thinnest portion of the gasket seal portion 44. The locking tab 46' thus has surfaces which contact the base 12 and the cover 14 and prevent the combination shock absorbing bumper and gasket seal 40 from being pulled out or removed during an impact or handling.
FIG. 4 is a top cut away view of the combination bumper and gasket seal 40 along one of the longer sides of the drive and near the disk 34. The combination bumper and gasket seal 40 includes cutouts in the gasket seal portion 44. The cutout 48 are along a radius which is slightly larger that the radius of the disk 34. The disk drive is designed such that the cutout provides an adequate amount of room during an impact so that the portion near the cutout 48 of the combination bumper and gasket seal 40 will not contact the edge of the disk 34 during an impact. It should be noted that an elastomeric bumper must be designed with the specified impact load the disk drive is to undergo in mind. The material must be selected so that it is not so soft that various parts of the disk drive contact during an impact. In addition, the material must be selected so that it is not so hard that no shock absorbing takes place.
Now turning to FIG. 5, a cross sectional view of the combination bumper and gasket seal 40 in the area near the disk is shown. The cross sectional view in FIG. 5 is representative of the combination bumper and gasket seal 40 along the longer sides of the disk drive 10. As shown in FIG. 5, the base 12 includes a semicircular relief 13 near the edge of the base 12. Similarly the cover 14 also includes a semicircular relief 16 which is also near the edge of the cover 14. The gasket seal portion 44 of the combination bumper and gasket seal 40 is sandwiched between the cover 14 and the base 12 in the assembled position shown in FIG. 5. When assembled, the base 12 combination bumper and gasket seal 40, and the cover 14 form a seal which enables the disk drive 10 to make a sealed disk enclosure 56. As shown in FIG. 5, the gasket seal portion 44 is sandwiched between the cover 14 and base 12. The locking tab 46" extends into and contacts the semicircular relief 13 in the base and the semicircular relief 16 in the cover so that the combination bumper and gasket seal 40 is locked into position and will not come out in the event of an impact. It should also be noted that the bumper portion 42 extends to the height of the cover 14 and the base 12 along the long sides of disk drive 10. On the long sides, the bumper portion 42 is less than the total height, h, of the disk drive 10.
FIG. 6 is another cross sectional view of the disk drive across the connector end 62 of the drive 10. Shown in FIG. 6 is the cover 14, the base 12, the connector 60 and the connector portion 54 of the gasket seal 44 of the combination bumper and gasket seal 40. Also shown is another electrical connector 66 which is near the connector 60. The electrical connector 66 connects the connector 60 and the expanded flex cable or regular printed circuit card 67. The electrical connector 66 can be a flex cable. It is also contemplated that the electrical connector 66 and the expanded flex cable or regular printed circuit card 67 can be one continuous flex cable. The electrical connector 60 includes several pins which attach to the connector 66 and then to the expanded flex cable or regular printed circuit card 67. Although shown in FIG. 1 on the inside of the disk enclosure, the expanded flex cable or regular printed circuit card 67 could also be positioned either inside or outside the disk enclosure. Turning briefly to FIG. 1, the expanded flex cable or regular printed circuit card 67 shown in this preferred embodiment is positioned inside the disk enclosure. The expanded flex cable or printed circuit card is glued or bonded to the base on the inside of the disk enclosure. Components populating the flex cable or printed circuit card which are too large to incorporate within the flex cable or printed circuit card, and which are prone to outgassing, are sealed to lessen outgassing. It should also be noted that the flex cable or printed circuit card 67 has a footprint which is substantially equal to the footprint of the sealed disk enclosure portion associated with the base 12. When assembled the flex cable or printed circuit card 67 fits on the floor of the base 12 beneath the disk 34. Returning to FIG. 6, the connector portion 54 of the gasket seal is sandwiched between the cover 14 on one side of the connector portion 54 and the connector 66 and base 12 on the other side of the connector portion 54 of the gasket seal 44. When fully assembled this forms the sealed disk enclosure 56 of the disk drive 10.
FIG. 7 is an isometric cut away view of the end of the disk drive 10 which houses the connector 60. As shown in FIG. 7 the base 12 includes locking features 68 which mate with tabs 70 on the connector 60. When assembled the tabs of the connector 60 fit within the locking features on the base 12 to provide strain relief for or between the connector 60 and the pins attached to the flex cable 66. Thus when the disk drive 10 is inserted or removed from the slot which takes the disk drive (not shown) the forces will not be transmitted to the flex cable 66 but rather to the base 12. The combination gasket seal and bumper 40 also includes locking features 72 which correspond with the locking features on the base 12 and which also mate with the tabs 70 of the connector 60. These locking features prevent the combination bumper and gasket seal 40 from being removed from the connector end 62 of the disk drive 10 due to an impact or due to regular or rough handling. The locking features also help to seal the disk drive near the connector 60.
FIG. 8 shows an isometric view of a first embodiment of the disk drive as shown in FIGS. 1 through 7 above. The disk drive shown in FIG. 8 is in its assembled state rather than the exploded view shown in FIG. 1. This disk drive is a PCMCIA Type II device that has a height of 5.0 mm. The length and width of the PCMCIA Type II disk drive is equivalent to a common plastic credit card. The PCMCIA Type II has certain height limitations along all sides of the disk drive so that the drive will fit into a corresponding PCMCIA Type II drive. The height of the drive along its length is less than the full height, 5.0 mm, of the PCMCIA Type II disk drive. Since the height along the length of the disk drive is less than the full height, 5.0 mm, of the disk drive, this embodiment is somewhat prone to damage due to a flat drop, which is a drop such that a substantial portion of the base 12 or cover 14 will contact the surface when dropped.
FIG. 9 shows a view of a disk drive 10 having the combination bumper and gasket seal 40. Shown on the surface associated with the cover 14 are elastomeric pads 50 which extend the height of the disk drive 10 to a height greater than the height, h, of the disk drive as shown in FIGS. 1 through 8. The elastomeric pads 50 are located on cover 14 and base 12 (not shown). Elastomeric pads 50 will prevent damage due to flat drops where the disk drive would land on the surface defined by either the majority of the base 12 or the majority of the cover 14. The disk drive 10 which includes additional pads 50 extending above the height, h, of the disk drive would be useful where a PCMCIA Type II drive would fit into a slot in a computer with a disk drive slot larger in height than 5.0 mm. One such application would be for fitting a PCMCIA Type II disk drive into a slot for a PCMCIA Type III disk drive which would have a height of 10.5 mm.
FIG. 16 shows a cross-sectional view of the disk drive 10 with pads 50 along one of the edges of the drives. The pads 50 in FIG. 16 are shown closer to the edge of the drive than the pads of FIG. 9. The pads 50 can be placed as close to an edge as possible. The limiting factor for pads 50 placement will be to allow the drive to slide in and out of the slot (not shown). It is also necessary to use at least three pads 50 so as to define a plane on one of the base or cover. A single solid pad covering a major portion of the cover 14 or base 12 could also be used just as effectively.
Now turning to FIG. 10, a second preferred embodiment of a shock absorbing system for a disk drive 10 is shown. Of course the disk drive 10 will include many of the same internal components as the disk drive shown in FIGS. 1 and 2. As a result, the description of the second preferred embodiment will not include a description of all the internal portions of the disk drive for the sake of brevity of this description. The disk drive shown in FIG. 10 has a connector 60 located on one end of the disk drive. The disk drive thus has a connector end 62 and a short side 64 of the drive 10. The disk drive of this second embodiment of the disk drive 10 includes four pivotally mounted elastomeric bumpers 80. The elastomeric bumpers 80 are attached to a frame 82 of the disk drive. Openings in the frame 82 allow the elastomeric bumpers 80 to be mounted pivotally and also allow the elastomeric bumpers to be pivoted to a position where the elastomeric bumpers are at the same height as the height, h, of the disk drive. Along the short side 64 of the disk drive of the second embodiment and more particularly at the corners of the short side 64 of the drive are two elastomeric end caps 86 near the connector end 62. Attached or bonded in one of many known ways to the frame 82, is a connector shroud 84. The connector shroud and frame are further detailed in FIG. 11 below. Advantageously the rotatable elastomeric bumpers 80 can be rotated into a position where their height is greater than the height, h, of the disk drive. This prevents damage to the drive in the event of a flat drop where a substantial portion of the base 12' or a substantial portion of the surface associated with the cover 14' would contact the surface onto which it was dropped.
Now turning to FIG. 11, the frame 82 and the connector shroud 84 will be further detailed. The frame 82 includes recesses at the corners associated with the short side 64 of the frame or disk drive 10. These recesses are for receiving the elastomeric end caps 86. There are elongated recesses on each side of the frame 82 which intersect with the connector end 62 of the disk drive 10. The elongated recesses 90 include an additional small recess 92 for receiving an additional elastomeric bumper 88. It should be noted that these elastomeric bumpers 88 are in addition to the pivotable elastomeric bumpers 80. The elastomeric bumpers 88 fit within the small recesses 92 in the elongated recesses 90 of the frame. The connector shroud 84 then fits over the small elastomeric bumpers 88 in the recesses and engages the elongated recess 90 which has a rib 96 which fits into a channel 98 in the connector shroud 84. The shroud is bonded to the frame.
Now turning to FIG. 12, which is a top view of a corner of the drive near the connector end 62 of the drive 10 as it is being loaded due to an impact, the operation of the shock absorbing elastomeric bumper 88 in the small recess 92 of the frame 82 will now be discussed. In the event of an impact load on the corner, the connector shroud 84 pivots about point 100. As it pivots the connector shroud compresses the small shroud bumpers 88 near the corner where the impact is occurring. The pivot point 100 occurs at the point where the rib 96 and the frame for receiving the shroud ends within the channel 98 of the connector shroud 84. Thus it can be seen that when an impact occurs on a corner the connector shroud 84 transfers the impact load to the shroud bumper 88 and disperses the impact load across the shroud bumper. After the impact load has passed the shroud bumper 88 returns to its original position and pushes the connector shroud back to its static position.
FIG. 13 shows a side view of the second embodiment of the disk drive 10 at sequential times during insertion of the drive into a disk drive bay. In FIG. 13a the disk drive is going into the bay however, with the elastomeric bumpers 80 in their extended positions. The center line shown is understood to be the center line of the disk drive bay (not shown). In FIG. 13b the wall of the drive bay contacts the pivotable elastomeric bumper 80 which is shown. In FIG. 13c the disk drive is further inserted into the drive bay (not shown) and the wall 110 pivots the elastomeric bumper 80 further out of the extended position. FIG. 13d shows the disk drive 10 further inserted into the drive bay with the wall 110 almost past the elastomeric bumper 80. In FIG. 13d the elastomeric bumper 80 has been pivoted to the position where the height of the elastomeric bumper is equal to or less than the height of the disk drive 10. Of course when the second elastomeric bumper 80 on the same side contacts the wall 110 the same sequence will reoccur as the drive is fully inserted into the disk drive bay (not shown).
It should be noted that with respect to FIG. 11 the base 12' and the cover 14' are bonded to the frame to form a sealed disk enclosure.
Further it should be noted that the rotatable or pivotable elastomeric bumpers 80 of the second preferred embodiment could also be included in the first embodiment of disk drive 10 shown and described in FIGS. 1 through 9.
Now turning to FIGS. 14 and 15, a shock watch sensor 111 will be described. The shock watch sensor 111 is included in the disk drive 10. Preferably, the shock watch sensor 111 is housed within the disk drive 10 and has a transparent cover 115 which is in either the cover 14 or the base 12 of the disk drive. The shock watch sensor 111 is mounted on the base 12 and undergoes a color change after a disk drive is subjected to shock loading in excess of a prespecified level. The shock watch sensor 111 further includes a capsule 112 filled with a colored liquid. Surrounding the capsule 112, is a porous material 114. The capsule 112 and porous material 114 is also in a container which in turn is attached to the base 12 of the disk drive 10.
In operation, the capsule 112 will break when the disk drive 10 undergoes a shock load which is in excess of a prespecified level. The fluid in the capsule 112 spills into the porous material 114. By capillary action, the colored fluid spreads throughout the porous material 114 so that it is visible through the transparent cover portion of the disk drive 10. Once broken, a person can quickly determine if the disk drive 10 has undergone a shock over a preselected level. The shock watch 111 is particularly useful for consumers. It is thought that PCMCIA Type II and PCMCIA Type III drives will be widely available to consumers through a variety of distribution points. When consumers go to a store to pick up a disk drive, the consumer can check a drive to make sure it has not undergone a shock of a preselected level. Thus, consumers confidence in the quality of the disk drive will be improved since the consumer will know that the disk drive has not been damaged due to a shock before purchasing the drive. Store owners will also know when a box of disk drives has been dropped or mishandled during shipment and can settle the matter with the shipper or manufacturer. In addition, the manufacturer would know when a disk drive had undergone a shock of a selected level if the disk drive had been returned under warranty or after a field failure. It should be noted that the shock watch 111 can be designed to trigger at any specified shock load level.
The present invention and the best modes for practicing it have been described. It is to be understood that the foregoing descriptions are illustrative only and that other means and techniques can be employed without departing from the full scope of the invention as described in the appended claims.
|
A disk drive has at least one disk for storing data and at least one transducer for reading or writing data to or from the disk. The transducer is attached to an actuator which positions the transducer with respect to the disk. The actuator includes a controllable motor which is used to move the actuator and the transducer attached thereto. The disk drive also includes a ramp for off loading the transducer or for parking the transducer off of the surface of the disk. The disk drive includes a combination shock absorber and gasket that has locking tabs to keep the combination shock absorber and gasket in place during a shock or impact loading event. The combination shock absorber and gasket also can be provided with additional extensions to lessen shocks caused by flat drops. Elastomeric blocks or pads can be provided on the cover and the base to lessen shocks caused by flat drops. The drive can also have rotatable elastomeric blocks that can rotate to a position above the disk drive to lessen shocks resulting from flat drops. The drive also is provided with a shock sensor which provides visual evidence that the drive has undergone a shock of a predetermined threshold. Another shock absorbing system uses a shroud around the connector on the disk drive.
| 8
|
RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Patent Application Ser. No. 60/870,152, filed Dec. 15, 2006, the entire contents of which are hereby incorporated by reference.
BACKGROUND
[0002] The present invention relates to a control system for a refrigerated merchandiser that heats a glass door of the merchandiser to eliminate condensation on the glass door. More particularly, the present invention relates to a control system for a refrigerated merchandiser that initiates a heating process for a glass door of a refrigerated merchandiser using a controller in response to a change in a position of the glass door.
[0003] Existing refrigerated merchandisers display fresh and frozen food product in a product display area, and include glass doors to provide visibility of the food product and product accessibility to consumers. Often, condensed moisture accumulates on the exterior surface of the cold glass, which obscures viewing of the product in the merchandiser. The moisture in the relatively warm ambient air of the store can condense on the outside surface of the glass door. Similarly, moisture can condense on the cold inside surface of the glass door when the door is opened. Without heating, the condensation on the outside and inside of the glass door does not clear quickly and obscures the food product in the merchandiser. Long periods of obscured food product caused by condensation may detrimentally impact sales of the food product.
[0004] Some glass doors include a resistive coating or semi-conductive film (e.g., tin-oxide) adhered or affixed to the glass door to remove condensation and fog. The resistive coating supplies heat to the glass door via current flow through the coating caused by a supply of electrical potential or electricity from the merchandiser. Typically, the heat applied to the glass door is controlled by a controller based on a duty cycle. These duty cycles are varied between an “on” state (i.e., heat applied to the glass door) and “off” state to regulate the time that heat is applied to the glass door, and are generally defined by the percentage of time that the duty cycle is in the “on” state.
[0005] Some merchandisers employ a knob or other manual control that can be used by an operator to set the percentage of time that the duty cycle is in the “on” state based on the experience of the operator. Other existing merchandisers include a sensor to sense parameters of the ambient environment surrounding the merchandiser (e.g., humidity, temperature). A controller is in electrical communication with the sensor, and determines a duty cycle to remove condensation from the glass door based on the sensed parameters.
[0006] Typically, sensors of conventional control systems are attached to the merchandiser at a relatively large distance from the glass door and the refrigerated product display area (e.g., on an exterior wall of the merchandiser, on a wall adjacent the merchandiser) to avoid an adverse impact on the sensed parameters caused by infiltration of relatively cold, dry air when the glass door is opened. However, placement of conventional sensors at relatively long distances from the glass door limits the effectiveness of the sensor to accurately measure ambient conditions adjacent the glass door. As a result, the duty cycle determined by the controller may not be adequate to clear the glass door because insufficient heat may be supplied by the resistive coating. Insufficient heat applied to the glass door can cause poor dissipation of condensation and fog. Similarly, inaccurate measurements by the sensor may cause the controller to supply too much heat to the glass door, resulting in increased energy costs.
[0007] Existing control systems regulate heat applied to glass doors based on a predetermined duty cycle. These control systems supply electrical potential to the glass door based on the predetermined time that the duty cycle is in the “on” state. The time that the duty cycle is in the “on” state is regulated to limit energy use by the merchandiser. Once the duty cycle enters the “off” state, no electrical potential is supplied to the glass door. When the glass door is opened during the predetermined time that the duty cycle is in the “off” state, condensation may readily form on the interior and/or exterior of the glass door.
[0008] Conventional control systems cannot eliminate condensation that forms on the glass door when the duty cycle is in the “off” state. Instead, heat is applied to the glass door to remove condensation only when the duty cycle is in the “on” state. As such, the duty cycle regulated by conventional control systems can adversely affect elimination of condensation from the glass door due to a relatively long period of time between the glass door being opened and the duty cycle entering the “on” state. The inability of existing control systems to actively remove condensation from glass doors in response to formation of condensation allows condensation to remain on the glass doors for a long time, and detrimentally impacts the viewability of the food product.
[0009] Similarly, conventional control systems cannot compensate for multiple door openings that occur in a relatively short period of time to adequately clear condensation and fog from the glass doors. For example, when multiple door openings occur and the duty cycle is in the “off” state (i.e., no heat applied to the glass door), condensation can accumulate on the glass door. The condensation is not removed by the control system until the duty cycle enters the “on” state. Depending on the duty cycle, a relatively long period of time can elapse between the last of the multiple door openings and entry of the duty cycle into the “on” state. As a result, the glass door can remain obscured by condensation for a relatively long time.
SUMMARY
[0010] In one embodiment, the invention provides a method of operating a refrigerated merchandiser that includes a case that defines a product display area, and at least one door that provides access to the product display area. The method includes sensing a parameter of an ambient environment adjacent the case, delivering a signal indicative of the sensed parameter to a controller, and determining a duty cycle using the controller based on the signal indicative of the sensed parameter. The method also includes detecting a change in the sensed parameter using the controller, interrupting the duty cycle by initiating a clearing interval using the controller in response to the controller receiving the signal indicative of the change in the sensed parameter, and clearing condensation from the door during the clearing interval.
[0011] In another embodiment, the invention provides a method of operating a refrigerated merchandiser that includes a case that defines a product display area, and at least one door that provides access to the product display area. The method includes sensing a parameter of an ambient environment adjacent the case, determining a duty cycle using the controller based on the signal indicative of the sensed parameter, detecting the occurrence of a door event of the door in response to the door moving between a first position to a second position, interrupting the duty cycle by initiating a clearing interval using the controller in response to the door event, and clearing condensation from the door during the clearing interval.
[0012] In yet another embodiment, the invention provides a refrigerated merchandiser that includes a case and at least one door coupled to the case. The case defines a product display area and includes a casing that has at least one mullion defining an opening that is in communication with the product display area. The door provides access to the product display area and substantially encloses the product display area, and includes a glass member that has a conductive film. The refrigerated merchandiser also includes at least one sensor and a controller. The sensor is positioned adjacent the door, and is in communication with the opening to detect a door event of the door and to generate a signal indicative of the door event. The controller is in communication with the sensor to receive a signal indicative of the door event from the sensor, and is further in communication with the conductive film to initiate a clearing interval to clear condensation from the door in response to the signal indicative of the door event.
[0013] Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of an exemplary refrigerated merchandiser that includes a plurality of doors and a control system.
[0015] FIG. 2 is a perspective view of the doors and a casing of the refrigerated merchandiser of FIG. 1 .
[0016] FIG. 3 is an enlarged front view of the refrigerated merchandiser of FIG. 1 , including a sensor of the control system coupled to the casing adjacent a closed door.
[0017] FIG. 4 is an enlarged perspective view of the refrigerated merchandiser of FIG. 1 , including the sensor attached to the casing adjacent an open door.
[0018] FIG. 5 is a schematic view of one embodiment of a process of the control system for determining a clearing interval for the doors.
[0019] FIG. 6 is a schematic view of another embodiment of a process of the control system for determining a clearing interval for the doors.
[0020] FIG. 7 is a perspective view of the sensor of FIG. 3 attached to the casing.
DETAILED DESCRIPTION
[0021] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
[0022] FIG. 1 shows a refrigerated merchandiser 10 for displaying food product (not shown) available to consumers in a retail setting (e.g., a supermarket or grocery store). The refrigerated merchandiser 10 includes a case 14 that has a base 18 , side walls 22 , a case top 26 , and a rear wall 30 . At least a portion of a refrigeration system (not shown) can be located within the case 14 to refrigerate the food product. The area partially enclosed by the base 18 , the side walls 22 , the case top 26 , and the rear wall 30 defines a product display area 34 . The food product is supported on shelves 38 within the product display area 34 .
[0023] The case 14 includes a casing 42 adjacent a front of the merchandiser 10 . FIG. 2 shows that the casing 42 includes vertical mullions 46 that define openings 50 to allow access to food product stored in the product display area 34 . The mullions 46 are spaced horizontally along the case 14 to provide structural support for the case 14 . Each mullion 46 is defined by a structural member that can be formed from a non-metallic or metallic material. The mullions 46 are substantially hollow, and can be filled with insulating foam (not shown). In some constructions, a light assembly 54 may be attached to a surface of the mullions 46 adjacent the product display area 34 to illuminate the food product.
[0024] As illustrated in FIGS. 1 and 2 , the case 14 further includes doors 58 pivotally attached to the casing 42 using upper and lower hinge assemblies 62 . Each door 58 is positioned over a respective opening 50 to allow access to the food product in the product display area 34 . A handle 66 is positioned along an edge of the door 58 to move the door 58 between an open position and a closed position.
[0025] Each door 58 includes a door frame 70 and a glass member 74 . The door frames 70 can be formed from materials (e.g., polyurethane) that have relatively low thermal conductivity for minimizing thermal losses. In other constructions, the door frame 70 may be formed from other suitable material capable of supporting the glass member 74 (e.g., aluminum, steel, composites, etc.).
[0026] One glass member 74 is secured to each door 58 by a respective door frame 70 to allow viewing of the food product from outside the case 14 . In some constructions, the glass member 74 may include three panes of glass. In other constructions, the glass member 74 may include more or fewer than three glass panes (e.g., one pane of glass, four panes of glass). Generally, multiple panes of glass are spaced apart from each other and held in generally parallel, face-to-face positions relative to each other by the door frame 70 . In some constructions, one or more of the glass panes may include a low-emissivity coating.
[0027] Condensation generally forms on a surface of the glass member 74 when the temperature of the surface is lower than a dew point of air that is in contact with the surface. Condensation is a result of a combination of surface temperature and moisture in the surrounding air. Thus, condensation can form on an interior surface of the glass member 74 after the door 58 has been opened due to exposure of the generally cold interior surface to generally warm ambient conditions. Similarly, condensation can form on an exterior surface of the glass member 74 when the temperature of the exterior surface is below the dew point of the ambient air.
[0028] In the illustrated construction, an electrically conductive film or resistive coating (not shown) is adhered to the interior surface of each glass member 74 . The conductive film is generally transparent to minimize interference with viewing the food product stored in the product display area 34 . In some constructions, the conductive film may be adhered to the exterior surface of the glass member 74 , or alternatively, to the interior surface and the exterior surface.
[0029] FIG. 1 shows that the merchandiser 10 further includes a control system that has a sensor 86 attached to each mullion 46 , and a controller 90 in electrical communication with the merchandiser 10 and each sensor 86 via sensor leads 91 ( FIG. 7 ). The sensors 86 are located on the mullions 46 so that the sensors 86 are in communication with the openings 50 to detect when one or more doors 58 are opened and closed. The sensors 86 are also in electrical communication with the controller 90 to deliver signals indicative of the door positions to the controller 90 . In the construction illustrated in FIG. 7 , each sensor 86 is positioned substantially within the mullions 46 behind a mullion cover 87 , and is in communication with the openings 50 via a hole 88 in each mullion 46 . Each hole 88 generally faces outward from the mullion 46 into the opening 50 . In this construction, an insulating washer 89 can be used to secure each sensor 86 to the mullions 46 . In other constructions, the sensors 86 can be adhered to a surface of the mullions 46 . In still other constructions, the sensors 86 can be attached to the door frames 70 adjacent an edge of the doors 58 .
[0030] In some constructions, the sensors 86 are positioned adjacent the doors 58 and in communication with ambient air to detect one or more parameters of an environment surrounding the refrigerated merchandiser 10 . In these constructions, the sensors 86 are defined as environmental sensors, and can include a temperature sensing element and/or a humidity sensing element (not shown) to detect a temperature and humidity of the environment surrounding the merchandiser 10 . In other constructions, the sensors 86 can sense other environment parameters. Generally, the sensors 86 indirectly sense when one or more of the doors 58 are closed based on the sensed parameter (e.g., temperature and/or humidity). The temperature and humidity of the ambient air can be sensed by the sensors 86 at a predetermined time interval (e.g., one minute, two minutes, etc.), or alternatively, the measurements can be made continuously. In some constructions, the sensors are the SHT1x and SHT7x sensors provided by SENSIRION, which are described in the attached Appendix. In other constructions, the sensor 86 may detect other ambient conditions.
[0031] In other constructions, the sensor 86 can be defined as a door switch sensor that is positioned adjacent each door 58 to detect a position of the door 58 (i.e., opened and closed). In these constructions, a different sensing device (not shown) can be coupled to the case 14 to detect various conditions of the ambient environment.
[0032] The controller 90 is in electrical communication with the conductive film through the case 14 to regulate current through the conductive film ( FIG. 1 ) based on the signals received from the sensors 86 . The current is passed through the conductive film, which heats the glass member 74 to remove condensation. The controller 90 is a microcontroller that can be attached to the merchandiser 10 in any suitable location (e.g., the base 18 , on the case top 26 , etc.). Alternatively, the controller 90 may be remotely located from the merchandiser 10 .
[0033] FIGS. 5 and 6 show that the controller 90 determines a duty cycle or pulse width modulation period 94 to regulate heat applied to the glass member 74 based on the conditions of the ambient environment. In constructions that include the sensors 86 defined as environmental sensors, the signals indicative of the conditions of the ambient environment are delivered by the sensors 86 to the controller 90 to establish the duty cycle 94 . In constructions that include the sensors 86 defined as door switch sensors, the additional sensing device can deliver signals indicative of the conditions of the ambient environment to the controller 90 .
[0034] In some constructions, the control system can include one or more sensors 86 to detect ambient conditions of the environment, which send signals indicative of the conditions to the controller 90 for determining the duty cycle 94 for every door 58 . In these constructions, the duty cycle 94 is the same for each door 58 . In other constructions, the control system can include multiple sensors 86 , with one sensor 86 attached to the case 14 adjacent each door 58 to independently regulate the duty cycle 94 for the respective door 58 . In these constructions, the duty cycle 94 for one door 58 can be the same or different from the duty cycle 94 for the remaining doors 58 in a refrigerated merchandiser 10 that includes multiple doors 58 .
[0035] The duty cycle 94 is operated by the controller 90 over a predetermined time duration (e.g., 10 minutes), and is varied by the controller 90 between an “on” state 98 and an “off” state 102 to limit energy consumption of the case 14 . In some constructions, the duty cycle 94 can be varied between a first “on” state that corresponds to a first amount of electrical potential, and a second “on” state that corresponds to a second amount of electrical potential that is larger than the first amount of electrical potential. In other words, the duty cycle 94 in these constructions increases the electrical potential from a first electrical potential to a second, increased or higher electrical potential relative to the first electrical potential to remove condensation and fog from the glass member 74 . After the glass member 74 is cleared, the amount of electrical potential can be decreased from the second electrical potential to the decreased or lower first electrical potential.
[0036] The predetermined time duration represents one complete duty cycle 94 , i.e., the time needed for the duty cycle 94 to cycle through one “on” state 98 and one “off” 102 state. The duty cycle 94 is operated for a first predetermined time in the “on” state 98 (e.g., 4 minutes), and is operated for a second predetermined time in the “off” state 102 (e.g., 6 minutes). When the duty cycle 94 is in the “on” state 98 , heat is applied to the glass member 74 through the conductive film to remove or inhibit condensation. When the duty cycle 94 is in the “off” state 102 , current no longer flows through the conductive film and no heat is applied to the glass member 74 .
[0037] FIGS. 5 and 6 show the duty cycle 94 beginning in the “off” state 102 . In other constructions, the duty cycle 94 may begin in the “on” state 98 . The controller 90 renews the duty cycle 94 in response to expiration of the predetermined time duration. The duty cycle 94 is generally defined by the percentage of time that heat is applied to the glass member 74 (i.e., the first predetermined time relative to the time period defined by one complete duty cycle 94 ). For example, a forty percent duty cycle 94 for a predetermined time duration of ten minutes results in the duty cycle being operated in the “off” state 102 for six minutes (i.e., the first predetermined time), and operated in the “on” state 98 for four minutes (i.e., the second predetermined time). Thus, a relatively small percentage duty cycle 94 (e.g., 10 percent) corresponds to a relatively short second predetermined time, and a relatively large percentage duty cycle 94 (e.g., 90%) corresponds to a relatively long second predetermined time.
[0038] The controller 90 operates the duty cycle 94 in the “on” state 98 for the first predetermined time to clear condensation from the glass member 74 . The first predetermined time is generally a function of the temperature and humidity differential between the refrigerated product display area 34 and the ambient environment. When the differential is relatively large, a longer first predetermined time is needed to clear the condensation from the glass member 74 . When the differential is relatively small, a shorter first predetermined time is adequate to remove or inhibit condensation from the glass member 74 .
[0039] In operation, the control system periodically senses conditions of the environment to determine the duty cycle 94 . The controller 90 receives the signals indicative of the temperature and humidity from the sensor 86 , or alternatively from the sensing device. The duty cycle 94 repeats indefinitely to periodically apply heat to the glass member to inhibit condensation on the interior and exterior surfaces of the glass member 74 .
[0040] Each sensor 86 delivers a signal indicative of a door event 106 to the controller 90 when one or more doors 58 are opened. In other constructions, the door event 106 may be defined by one or more doors 58 in the closed position. The controller 90 selectively initiates a clearing interval 110 in response to the signal indicative of the door event 106 . The clearing interval 110 is defined by a predetermined period of time (e.g., 1 minute, 90 seconds, 2 minutes, etc.) that heat is applied to the glass member 74 to remove or inhibit condensation. In other words, the current flows through the conductive film to heat the glass member 74 when the controller 90 initiates the clearing interval 110 .
[0041] In some constructions, the control system initiates the clearing interval 110 simultaneously for each door 58 of a multiple door refrigerated merchandiser 10 without regard to which door 58 experiences the door event 106 . In these constructions, when a door event 106 is detected by one or more sensors 86 for a corresponding number of doors 58 , the clearing interval 110 is initiated for every door 58 . In other constructions, the control system can initiate the clearing interval 110 independently for each door 58 of a multiple door refrigerated merchandiser 10 . In these constructions, the controller 90 separately initiates the clearing interval 110 and overrides the duty cycle 94 for each door 58 that has experienced the door event 106 independent from the remaining doors 58 that have not experienced a door event 106 . The controller 90 continues to regulate condensation on the remaining doors 58 using the determined duty cycle 94 .
[0042] FIG. 5 shows one embodiment of the control system that selectively initiates the clearing interval 110 based on the humidity sensed by the sensor 86 . The controller 90 establishes a baseline humidity value based on signals from the sensor 86 indicative of the humidity of the ambient environment. The baseline measurements are generally determined on a rolling average of the sensed humidity over a period of time, and indicate an average of the ambient humidity that can be compared with subsequent measurements by the sensor 86 . In other constructions, the control system selectively initiates the clearing interval 110 based on the temperature sensed by the sensor 86 . In these constructions, the controller 90 establishes a baseline temperature value based on signals from the sensor 86 indicative of the temperature of the ambient environment. The baseline measurements are generally determined on a rolling average of the sensed temperature over a period of time, and indicate an average of the ambient temperature that can be compared with subsequent measurements by the sensor 86 . In still other constructions, the control system can selectively initiate the clearing interval 110 based on the temperature and humidity sensed by the sensor 86 , or alternatively, other parameters sensed by the sensor 86 . Generally, the controller 90 establishes a baseline humidity value and/or temperature value based on signals from the sensor 86 indicative of the temperature and/or humidity of the ambient environment.
[0043] Placement of the sensor 86 in close proximity to the glass members 74 subjects the sensors 86 to refrigerated air when the door 58 is opened to access the food product. When the door 58 is open, the sensor 86 detects the relatively cold, dry air from the product display area 34 rather than the ambient conditions outside the case 14 . The measurements of the cold, dry air by the sensor 86 are delivered to the controller 90 , and are compared with the baseline measurements.
[0044] As illustrated in FIG. 5 , the controller 90 determines the existence of a door event 106 based on the parameter (e.g., temperature, humidity, etc.) of the ambient environment sensed by the sensor 86 . Refrigerated air flows outward from the product display area 34 when the door 58 is opened, which decreases the temperature and humidity of the air adjacent the sensors 86 . In some constructions, a relatively large humidity differential results when the refrigerated air sensed by the sensor 86 is compared by the controller 90 with the baseline humidity. Similarly, a relatively large temperature differential can result when the refrigerated air sensed by the sensor 86 is compared by the controller 90 with the baseline temperature. After the relatively large humidity and/or temperature differential is determined by the controller 90 , the controller 90 discards the measurements of the refrigerated air made by the sensor 86 to avoid changing the duty cycle 94 in response to the refrigerated air.
[0045] Absent a door event 106 , the controller operates the duty cycle 94 without interruption by the clearing interval 110 . The controller 90 determines the existence of the door event 106 based on the relatively large humidity differential and/or temperature differential caused by refrigerated airflow adjacent the sensor 86 . When the door event 106 occurs, the controller 90 interrupts or overrides the duty cycle 94 and initiates the clearing interval 110 to remove or inhibit condensation on the glass member 74 . As illustrated in FIG. 5 , the controller 90 restarts the duty cycle 94 after the clearing interval 110 is complete (i.e., the predetermined period of time has elapsed). In other constructions, the controller 90 may restart the duty cycle 94 at the point where the duty cycle 94 was interrupted by the clearing interval 110 .
[0046] FIG. 6 shows another embodiment of the control system that initiates the clearing interval 110 in response to a door event 106 based on the signal from the door switch sensor 86 . The duty cycle 94 operates normally and without interruption when a door event 106 is not detected by the controller 90 (i.e., the door 58 remains closed). When the door 58 is opened, the signal indicative of the door event 106 is delivered to the controller 90 by the door switch sensor 86 . As discussed with regard to FIG. 5 , the controller 90 interrupts or overrides the duty cycle 94 and initiates the clearing interval 110 in response to the signal indicative of the door event 106 to remove or inhibit condensation on the glass member 74 . The controller 90 restarts the duty cycle 94 after the clearing interval 110 is complete (i.e., the predetermined period of time has elapsed). In some constructions, the controller 90 may restart the duty cycle 94 at the point where the duty cycle 94 was interrupted by the clearing interval 110 . In other constructions, the clearing interval 110 may be initiated in response to the closing of the door 58 as sensed by the door switch sensor 86 . In still other constructions, the clearing interval 110 may be initiated after a predetermined lapse of time after the door 58 is opened or closed as detected by the sensor 86 .
[0047] The control system determines the existence of the position of the doors 58 such that heat is applied to the glass members 74 immediately or very soon after the doors 58 move between open and closed positions. Initiation of the clearing interval 106 in response to door events 106 quickly removes or inhibits condensation on the glass members 74 . Once the clearing interval 106 is complete, the control system returns to normal operation.
[0048] Various features and advantages of the invention are set forth in the following claims.
|
A method of operating a refrigerated merchandiser. The refrigerated merchandiser includes a case that defines a product display area, and at least one door that provides access to the product display area. The method includes sensing a parameter of an ambient environment adjacent the case, delivering a signal indicative of the sensed parameter to a controller, and determining a duty cycle using the controller based on the signal indicative of the sensed parameter. The method also includes detecting a change in the sensed parameter using the controller, interrupting the duty cycle by initiating a clearing interval using the controller in response to the controller receiving the signal indicative of the change in the sensed parameter, and clearing condensation from the door during the clearing interval.
| 5
|
FIELD OF THE INVENTION
This invention relates to a temperature control and drip valve assembly for a steam iron. This invention is primarily concerned with household steam irons but aspects of the invention may be useful in other applications.
BACKGROUND OF THE INVENTION
Steam is created in a steam chamber of a steam iron by passing water through a drip valve onto the heated soleplate of the iron. Because different temperatures are required for satisfactory pressing of different fabrics, steam irons are provided with thermostats for adjusting the heat output of the heating element that heats the soleplate. A steam iron is incapable of producing steam at lower temperature levels and can produce increasing amounts of steam as the temperature levels increase. Because there is a correlation between the temperature of the soleplate and the amount of water which should be introduced into the steam chamber to produce steam satisfactory for ironing which is neither superheated and dry or unduly wet, steam irons are provided with mechanisms for varying the amount of water introduced into the steam chamber in accordance with the temperature settings of the heating element. These mechanisms also ensure that water will not be introduced into the steam chamber if the soleplate is insufficiently hot to produce steam. There is an ever-present need to provide improved assemblies for controlling the amount of steam produced, if any, relative to the temperature setting of the heating element.
SUMMARY OF THE INVENTION
This invention provides an improved temperature control and drip valve assembly for a steam iron.
An object of this invention is to provide an improved temperature control and drip valve assembly which provides for a positive control of the amount of water introduced into the steam chamber of a steam iron in relation to the temperature setting of the steam iron.
A temperature control in accordance with this invention includes a rotatable temperature control knob, a rotatable drive member connected to said knob for rotation therewith, and a thermostat having a rotatable temperature adjusting shaft connected to the drive member for rotation therewith. Rotation of the control knob can thereby be used to control the temperature generated by the heating element.
Further in accordance with this invention, the control knob has a vertical shaft having a downwardly-facing shoulder and the drive member has an upwardly facing shoulder confronting the downwardly-facing shoulder. The shoulders have complementary cam surfaces engaged by a cam follower which is integral with a vertically movable valve stem which has a lower end that cooperates with a valve seal to control the amount of water permitted to drip from a water reservoir into the steam chamber. Accordingly, rotary movements of the control knob to control the temperature generated by the heating element are also transmitted to vertical movements of the valve stem.
Further in accordance with this invention, a self-cleaning capability is provided for flushing the steam chamber and its steam vents by fully opening the valve port so that the steam chamber can be filled with water from the water reservoir. To this end, the control knob is vertically movable relative to said drive member through a limited distance which is sufficient to fully open the valve port, as will be described further below.
Other objects and advantages will become apparent from the following description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a steam iron made in accordance with this invention.
FIG. 2 is an exploded isometric view of the iron of FIG. 1 .
FIG. 3 is an exploded isometric view of parts of a temperature control and drip valve assembly and including parts of a spray and steam pump assembly which forms part of the iron of FIG. 1 .
FIGS. 4 and 5 are fragmentary elevational views illustrating the operation of a cam and a cam follower in controlling the vertical location of the valve stem.
FIGS. 6 and 7 are fragmentary cross-sectional views of the valve seal and the valve stem to illustrate the operation of the valve.
FIG. 8 is a fragmentary cross-sectional view of the lower portion of the valve stem taken along line 8 — 8 of FIG. 6 .
FIG. 9 is fragmentary view, partly in cross section, showing the raising of the cam follower for self-cleaning purposes.
DETAILED DESCRIPTION
With reference to FIGS. 1 and 2, the present invention is illustrated in connection with a household steam iron, generally designated 10 , having a soleplate 12 with a steam chamber 14 , covered by a base cover 16 which supports a handle 18 . Handle 18 has a lower portion 20 which confines a water reservoir 21 and an upper portion 22 which receives an electronic control module 24 and which is covered by a top cover 26 . The handle upper portion 22 and the top cover 26 constitute a handgrip. In addition, the iron 10 includes a rear cover 28 , temperature control knob 30 for setting a thermostat 32 mounted on the soleplate 12 , and a drip valve assembly including a drip valve stem 34 for dripping controlled quantities of water into the steam chamber 14 through a drip valve seal 35 . As well known, the water dripped into the steam chamber 14 is heated by an electrical heating element in the soleplate 12 , vaporizes and forms steam which exits from the soleplate 12 through plural steam vents (not shown). The heating element and the electronic controls are connected to house current by means of a power cord connected to the rear cover 28 . The particular iron 10 shown in the drawings also has a pair of manually-operable pistons 36 and 38 , respectively used to spray water forwardly of the iron through a nozzle 40 and to create a burst of steam by pumping water by way of a thermoplastic tube connection 42 into the steam chamber 14 .
The water reservoir 21 has a forwardly projecting, concave front face 44 and a water conduit 46 extending from the front face 44 into the hollow interior of the reservoir 21 . A fill port assembly, generally designated 48 , is used to enable one to pour water into the water reservoir 21 and also to cover the water conduit 46 during normal use of the iron to prevent contaminants from entering into the reservoir 21 .
With reference to FIG. 3, the temperature control knob 30 is mounted for rotation on a bearing 50 formed at the front end of the top cover 26 and has plural hooks 52 which extend into engagement with openings in a hollow control knob shaft 54 that is normally located below the bearing 50 . The knob 30 has an “off” or “0” mark which, when the knob 30 is rotated to a position in which the thermostat 32 prevents energization of the heating element 15 , is aligned with an indicator 56 on the top cover 26 . The proper orientation of the knob 30 is assured by means of a depending rod 58 that must be aligned with an opening 60 in the upper sidewall of the knob shaft 30 . The lower end of the knob shaft 54 extends into the hollow upper end of a rotatable drive member 62 and is connected to the knob shaft 54 for rotation therewith. The drive member 62 is rotatably mounted on the water reservoir 21 by hooks 62 A (FIG. 2 ). The drive member 62 in turn is connected by a metal connecting member 64 to an adjusting shaft forming part of the thermostat 32 in order to adjust the thermostat 32 to the desired heat level.
Relative rotation between the knob shaft 54 and the drive member 62 is prevented by the engagement between ribs 66 inside the hollow interior of the drive member 62 and a complimentary surface of the knob shaft 54 . The drive member 62 is connected to the knob shaft 54 by a pair of hook arms 65 (only one of which is shown in FIG. 3) that engage beneath a pair of diametrically opposed tabs 67 inside the upper end of the drive member 62 (again only one tab being shown in FIG. 3 ). This construction allows for the knob 30 and its shaft 54 to be raised relative to the drive member 62 for self-cleaning purposes, as will be described below.
The knob shaft 54 has a downwardly-facing shoulder 70 and the drive member 62 has an upwardly-facing shoulder 72 confronting the downwardly-facing shoulder 70 . The shoulders 70 and 72 have complementary cam surfaces which control the vertical height of the valve stem 34 as will now be described.
With reference to FIGS. 6, 7 and 8 , the valve stem 34 is molded in one piece and has a lower end which comprises a cylindrical body of a size to close the port in the valve seal 35 and a downwardly-extending notch or recess 74 of increasing dimension. As is apparent, the valve stem 34 , when lowered as shown in FIG. 6, fully closes the port in the valve seal 35 and opens the port by increasing degrees when the valve stem 34 is raised. The upper end of the valve stem 34 comprises an integral cam follower 76 that extends into the space between the shoulders 70 and 72 , an integral pair of arms 78 that engage the outer surface of the drive member 62 to prevent the valve stem 34 from rotating, and an integral triangular rear portion 80 that engages between the cylinder portions of the pump housing 81 so that the head of the valve stem 34 is always held in a position in which the cam follower 76 extends between the shoulders 70 and 72 .
FIGS. 4 and 5 show how rotation of the temperature control knob shaft 54 controls the height of the valve stem cam follower 76 . As shown in FIG. 4, there is a substantial length of the shoulders 70 and 72 which have no contour which would raise or lower the valve stem 34 . This is because the seal port is not opened until the temperature setting is sufficiently high to create steam. FIG. 5 shows a condition in which the valve stem follower 76 is raised to cause the valve stem 34 to be raised to create the condition shown in FIG. 7 in which water is dripped from the water reservoir 21 into the steam chamber.
A valve stem seal 82 is shown in FIG. 3 . This bears against the top portion of the water reservoir 21 through which the valve stem 34 extends. A U-shaped clamp 84 on the pump housing 81 holds the seal 82 in sealing relation to the water reservoir 21 .
In most positions of the temperature control knob 30 , the knob shaft 54 is prevented from being raised into the bearing 50 at the front of the top cover 26 by means of stop members 86 in the bearing 50 that engage a flange 88 on the outside of the knob shaft 54 . However, when the temperature control knob 30 is set to the “0” position, gaps 90 in the flange 88 are aligned with the stop members 86 so that the knob 30 can be elevated as shown in FIG. 9 . At the “0” position of the knob shaft 54 , a finger 92 on the knob shaft 54 engages under the cam follower 76 , so that the raising of the temperature control knob is accompanied by the raising of the valve stem 34 , and a corresponding full opening of the seal port. This operation can be used for self-cleaning of the soleplate as mentioned above.
Although the presently preferred embodiment of this invention has been described, it will be understood that within the purview of the invention various changes may be made within the scope of the following claims.
|
An improved temperature control and drip valve assembly which provides for a positive control of the amount of water introduced into the steam chamber of a steam iron in relation to the temperature setting of the steam iron. A self-cleaning capability is provided for flushing the steam chamber and its steam vents.
| 3
|
FIELD OF THE INVENTION
The present invention relates generally to a spinning rotor in an open-end spinning frame. More specifically, it relates to an improved spinning rotor which is made of steel and has part of its interior surfaces hardened.
BACKGROUND OF THE INVENTION
In rotor spinning of yarn using an open-end spinner, fibers which have first been separated into individual fibers by a combing or fiber opening mechanism and then drawn under the influence of a flowing air stream into the spinning chamber of the rotor, are collected within the peripherally extending fiber-collecting groove, formed along the maximum diameter region within the spinning chamber. The fibers thus deposited in the fiber-collecting groove are withdrawn continuously therefrom in the form of a twisted and elongated strand of yarn through the yarn guide tube. The rotor, which rotates at an extremely high speed, is conventionally made of an aluminium alloy having a relatively low specific gravity and moderate strength with a view to reducing power consumption in driving the rotor and to avoid damage or deformation of the rotor by the high centrifugal forces developed by the rotor as it is being driven at high speed.
However, the demand for improvement in open-end spinning productivity has boosted the rotor speed up to more than 30,000 rpm, with the result that the rotor of aluminium alloy used for a certain period of service has shown deformation or wear at the inner peripheral surface or fiber contacting surface along which the fibers are forced to slide during their introduction into the rotor under the influence of the centrifugal force, as well as at the fiber collecting groove formed at the maximum diameter in the spinning chamber of the rotor. Such wear is particularly rapid at the latter fiber collecting groove where the fibers are collected and then formed into a strand of yarn while being twisted. Thus, said fiber collecting groove is placed under continuous abrasive action by the fibers. Since the configuration of the fiber collecting groove plays a critical part in the formation of a yarn, any wear or deformation thereat is harmful and will naturally affect the process of yarn formation. As a result, the quality of the yarn being spun will be degraded.
There are several factors which are responsible for the above-stated wear of the rotor. One is the magnitude of impacting shocks which take place when the individual fibers flowing out of the fiber feeding tube impinge against the rotor's inner fiber contacting surface which is moving at a much greater peripheral speed than the fibers. Another is the abrasive action produced when such fibers are forced to slide in contact with the inner peripheral surface toward the fiber collecting groove under the influence of the centrifugal force developed by the rotor running at an extremely high speed. In addition to such impinging fibers, foreign matter or impurities contained in the fibers, such as grit, fragments of leaves or seeds, etc. promote rapid wear at the interior surfaces of the rotor. Furthermore, the fiber-collecting groove, where the fibers are twisted with each other to form a yarn under the influence of great centrifugal force and are subsequently withdrawn therefrom inwardly, against that centrifugal force, is subjected to an extremely high degree of continuous abrasive, frictional contact with the twisting yarn. Consequently, inordinate wear with consequent deformation of the groove configuration will take place after a period of spinning operation, thus deteriorating the quality of yarn which is spun out.
Many attempts were made to provide an improved aluminium rotor which could successfully withstand both high-speed operation and the above-mentioned abrasive forces for a sufficiently extended period of service, including surface treatment processes such as by coating, electro-plating or anodizing. Of these, anodizing of the rotor proved to be the best, because it exhibited the desired wear-resisting performance, thus retaining the originally machined flat surfaces of the fiber collecting groove and of the fiber contacting surface and causing the least change in the internal diameters of the rotor.
In recent years, under the demand for further increases of rotor speed up to from about 60,000 to 100,000 rpm for achieving still higher producitivity in spinning mills, the conventional rotor of aluminium alloy having anodized surfaces has been found inadequate for meeting the exacting requirements of rotor spinning at such super high speeds.
An approach to solving the problems associated with such conventional rotors has been proposed by U.S. Pat. No. 4,167,846, according to which the rotor body is made of steel and its interior surfaces are hardened by such treatment as induction heating, carburizing or nitriding. The surfaces obtained on the rotor by the method according to this prior art can offer adequate wear-resistance even at rotor speeds as high as 60,000 to 80,000 rpm. However, a rotor which has undergone such case hardening treatment has a disadvantage in that the heating necessary for the treatment is applied not only to the area which calls for hardening, but also to other portions in the rotor. As a result of such heating, strain or distortion will inevitably be produced within the rotor, causing harmful vibrations during the rotation thereof at a very high speed, thereby inviting degradation of yarn quality and rendering the rotor incapable of providing stable operation over a prolonged period of useful service.
SUMMARY OF THE INVENTION
With such background of the state of the art in mind, it is an object of this invention to provide an improved rotor for an open-end spinning frame, which avoids the above-mentioned disadvantages and drawbacks and whose interior surfaces exhibit adequate wear-resistance against the inflow of ordinary fibers, as well as of foreign materials such as grit or fragments of leaves or seeds.
This object of the invention is accomplished by fabricating the rotor of steel and applying a hardening treatment only to those surfaces of the rotor which require such hardening, thus avoiding strain or distortion within the rotor body itself.
The above and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a spinning rotor and its relevant parts in an open-end spinning unit, showing in a simplified way how fibers are fed into the rotor and a spun yarn is withdrawn therefrom;
FIG. 2 is a schematic sectional view showing an arrangement in which a rotor in accordance with one embodiment of the invention is being treated by a laser beam to produce localized surface hardening in the rotor;
FIG. 3 is a schematic sectional view, showing another arrangement for hardening selected surface areas of a rotor using a laser beam; and
FIG. 4 is a transverse sectional view of a rotor taken substantially along the fiber collecting groove thereof, and illustrating a manner of applying a laser beam treatment to the rotor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 which shows the general configuration of a rotor 2 for an open-end spinning frame (not shown), fibers 1 which have already been opened-up or separated into individual fibers by a combing roller (not shown) are transferred through a fiber feeding tube 7 into the circular spinning chamber 2A which is defined by the interior surfaces of the rotor. The fibers 1 thus introduced into the spinning rotor 2 are moved by centrifugal force along the downwardly and outwardly inclined interior peripheral surface or fiber contacting sidewall surface 6 to a peripherally extending fiber collecting groove 3 formed by the conjuncture between the sidewall surface 6 and the chamber bottom surface 6a at the maximum-diameter region within the spinning chamber, where the deposited fibers are formed into a continuous strand of twisted spun yarn 4. The spun yarn 4 is continuously withdrawn through a yarn guide tube 5, in well-known manner.
As previously mentioned, the fiber contacting sidewall surface 6 and fiber collecting groove 3 of the spinning chamber 2A are subjected to abrasion due to the frictional contact of fibers 1 and impurities, if any, such as grit or the like contained therein. Therefore, the rotor requires sufficient hardness to resist such wear, thereby to promote a longer period of useful life of the rotor with greater stability of operation. According to the embodiments of the invention, such requirements are achieved by providing a rotor which is made of steel and which has only portions of its interior surfaces hardened by heat-treatment using an emitted beam of high energy radiation, preferably a laser beam or a beam of electrons.
Because a rotor according to the present invention differs from a conventional rotor only with reference to the manner of surface hardening and not with reference to its overall shape or configuration, the same reference numerals as used in FIG. 1 are used to designate the rotor and rotor parts in the embodiments of the invention to be described.
Steel, if its carbon content is less than 0.5 percent, can be cut with the same degree of machinability as the aluminium alloy which has been selected heretofore as the material for the rotor body. This means that conventional machine tools for cutting aluminium alloy may be utilized to generate the smooth cut surfaces on a rotor made of such steel as those obtained on the aluminium alloy.
Reference is now made to FIG. 2 which illustrates one method by which the desired local areas of a rotor may be hardened in accordance with the present invention. A rotor 2 made of steel is rotatably supported in any convenient way and a beam of radiant energy, preferably a laser beam 9 emitted from a laser beam generator 8, is reflected by an angular mirror 10 and spot-focused by a lens 11 on a point or spot within the fiber collecting groove 3 of the rotor 2. In the laser apparatus shown in FIG. 2, the passage for the laser beam 9 is enclosed for protection thereof by an enclosure tube 12 so that the laser beam 9 which is transmitted through a one-way mirror 8a, may not be subjected to interferences on its way. In the illustrated arrangement, the laser beam 9 is emitted with a beam diameter of 22 mm through the one-way mirror 8a, which has a reflectivity of 95 percent, and is reflected by the angular mirror 10 to change its direction, whereupon it passes through the lens 11 with a beam diameter of 30 mm. The beam 9 is focused by the lens 11 and is directed and applied to the location within the fiber collecting groove 3 along which the surface hardening treatment is desired. In the arrangement of FIG. 2, the laser beam 9 is directed along the entire periphery of the fiber collecting groove 3 merely by turning the rotor 2 on its axis of rotation, the mirror 10 and the lens 11 being held in stationary positions. The rate of turning depends upon how rapidly the rotor chamber surface areas achieve the required hardening temperature for the steel rotor material selected after which the surface is immediately cooled by removal of the beam.
Because of its extremely high coherence, the laser beam 9 can be controlled very precisely and can be directed against the target point or spot through adjustment of the mirror 10 and the lens 11. Accordingly, it can be easily directed and focused upon locations of difficult accessibility located deep within the rotor 2. When it is focused properly by the lens 11, the light energy from the laser beam 9 is concentrated in an extremely limited area or spot, thereby increasing its energy per unit area. The light energy is converted into heat energy as it strikes the point of application on the rotor. Therefore, only that area of the rotor which is subjected to the laser beam 9 is heated, and the desired degree of temperature can be reached in an extremely short time. When emission of the beam 9 is stopped, the heated area cools by itself, thus completing the localized surface hardening treatment. As will be apparent from the foregoing, unlike conventional methods of surface hardening, the self-cooling feature of the invention eliminates the need for forced cooling of the metal by a coolant such as water or oil.
This surface hardening by use of a laser beam 9 does not produce any strain or distortion in the rotor 2 because the laser beam heats only those areas which are subjected to the influence of the beam, and the heat build-up within the rotor itself is quite negligible. A rotor 2 which is heat-treated in this way and which therefore has virtually no strain or distortion therein, not only has its interior surfaces hardened sufficiently to resist wear or deformation, but also has exceptionally high stability during the spinning operation at speeds of more than 80,000 rpm over a protracted period of time. Thus, the above-mentioned problems resulting in poor quality of yarn may be eliminated successfully.
The Table below reveals the results obtained from experiments on surface hardening of rotors using a carbon dioxide (CO 2 ) laser beam having an emitted wavelength of 10.6 μmm and 1 kW of output power, and wherein the laser beam is focused to a spot diameter of one-half (0.5 mm) millimeter (lens focal distance: 250 mm) and the rotor is rotated at a speed of four (4 rpm) revolutions per minute during the surface hardening process.
______________________________________ After TreatmentRotor Before Treatment Depth ofMaterial Surface Hardness Hardening Surface Hardness(JIS) (Vickers Number) (mm) (Vickers Number)______________________________________S45C 180 0.3 850S25C 140 0.3 600SUS440C 280 0.3 870______________________________________
For reference, the above materials designated as S45C, S25C and SUS440C according to JIS (Japanese Industrial Standard) correspond substantially to SAE (Society of Automotive Engineers) 1045, 1024 and 51440C, respectively.
Though heat treatment for the periphery along the fiber collecting groove 3 is performed in FIG. 2 by rotating the rotor 2 on its rotational axis for successively changing the position of laser beam 9 application, the same periphery may be heat-treated by rotating the mirror 10 while the rotor 2 is set in a fixed position as shown in FIG. 3. If desired, the mirror 10 in FIG. 3 may be made tiltable so as to direct the laser beam 9 across the periphery, or both the rotor 2 and the mirror 10 may be tiltable and/or movable. Furthermore, instead of changing the location of application of the laser beam 9 in a continuous manner along the rotor periphery, the laser beam 9 may be applied in a successive spot-to-spot manner along the periphery. As a further alternative, the laser beam 9 may be directed first to an arbitrarily selected spot or area "A" (see FIG. 4) and subsequently to the spot or area "B" which is farthest away from the spot "A" along the groove 3, and then to the spots "C" and "D", and so on in intermittent sequence, so that each shot of the laser beam 9 is applied to the area which is farthest from that to which the immediately preceding shot was directed.
Though the above-mentioned experiment on rotor surface hardening was made using a CO 2 laser, other types of lasers, such as a yttrium aluminum garnet (YAG) laser or ruby laser, may be employed. Other appropriate forms of radiant energy, such as an electron beam might also be used in place of the laser beam 9 in the same way and for the same purpose of locally heating and thereby surface hardening the rotor 2.
Thus, a spinning rotor according to the present invention is made of steel and has only a portion of its interior surfaces, including the fiber collecting groove formed at the region of maximum diameter in the rotor, heat-treated and hardened by a laser beam or an electron beam. The thus treated rotor is capable of providing excellent wear-resistance which can endure the abrasive action of incoming fibers and any foreign matter contained therein such as grit, while maintaining a high degree of stability in operation at extremely high speeds over a prolonged period of useful service.
|
An improved spinning rotor for an open-end spinning frame is disclosed herein, according to which the rotor is made of steel, and selected portions of its interior peripheral surfaces, including the fiber-collecting groove thereof, which is formed along the maximum-diameter region within the spinning chamber, are heat-treated by a focused laser beam or focused electron beam to harden the same. Due to the nature of laser beams, only those areas which require surface hardening are heat-treated without heating the entire rotor body, so that no strain or distortion is developed in the rotor during the heat treatment process. As a result, the rotor is heat-treated to provide excellent wear-resisting properties and exceptional stability in operation at an extremely high speed for an extended period of service.
| 3
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims foreign priority benefits under 35 U.S.C. §119 from German patent application Ser. No. 10 2004 004 059.1 filed Jan. 27, 2004.
TECHNICAL FIELD
[0002] The present invention relates to a method for producing an oxide ceramic shaped part, as well as to an oxide ceramic shaped part.
BACKGROUND OF THE INVENTION
[0003] Methods for the production of an oxide ceramic shaped part have been known for a long time. For example, it is known from WO 95/35070 to produce a ceramic shaped part. In this approach, the ceramic is infiltrated. The production of an oxide ceramic shaped part of this type is, however, relatively time-consuming; the step alone of the infiltration that is undertaken in connection with this approach, requires, for example, 4 hours.
[0004] Furthermore, it is known from EP-A 1 834 366 to produce a ceramic piece that is produced via the infiltration of a melted matrix material into the hollow space of a blank. A particular particle size with two different size gradations is provided for the infiltration substance. In connection with this approach, a covering material is used that is provided with a soluble salt that must be removed after the infiltration and the solidification step. The disadvantage of this approach is the need for the high process temperature during the shaping and the complicated hardware-intensive production.
[0005] The publication WO 88/02742 discloses the production of a ceramic component having a hardened outer surface. A porous AlO 2 blank is infiltrated with a zirconium oxide infiltration material so that the finished ceramic work piece comprises a volume portion of 1 to 15% zirconium oxide and, thus, the so-formed aluminum oxide ceramic is solidified. This process requires several infiltration steps and is suitable if a relatively soft ceramic such as aluminum oxide is to be hardened, while it is to be understood that a zirconium oxide ceramic with a high critical stress intensifying factor cannot be further hardened or strengthened via the addition of zirconium oxide. A ceramic of this type exhibits a strengthening only on its outer surface and, to produce a suitable work piece via this approach, the process steps must frequently be implemented in a serial manner.
[0006] Furthermore, DE-A1 198 52 740 discloses the configuration of a cap, or the configuration of other dental pieces, of aluminum oxide ceramic. The pre-sintered shaped part is infiltrated in the heated condition with a glass, which melts upon the introduction of the shaped part into the sintering oven. The infiltration requires, in connection with this approach, a timeframe of approximately 4 hours and a high press temperature. On top of this, the process is decidedly difficult to control and the mechanical properties of the dental piece are correspondingly poor.
[0007] Additionally, DE-A1 100 61 630 discloses the production of a full ceramic dental restoration piece comprised of a dental ceramic of zirconium oxide and aluminum oxide, whereby an infiltration with glass in a volume range of 0 to 40% is undertaken. This approach additionally requires, in connection with the deployment of such a dental restoration piece, the use of a mixture ceramic. A disadvantage of this approach is the reduced securement properties of the ceramic, which has been solidified via the glass phase.
[0008] Moreover, EP-A1 1 025 829 discloses the production of a cap of a ceramic material infiltrated with glass. In order to provide the desired translucence, two additional coatings are provided, which are applied onto the cap. In connection with the preparation of the dental restoration pieces, it is, due to aesthetic reasons, critical that the natural dental enamel be simulated, such natural dental enamel having an increased translucence while the dentine has a reduced translucence. In this connection, the coatings 7 and 6 are provided in accordance with the disclosed approach. In a process of this type, the detailed further working involving the grinding of the infiltrated fixed body into a powder is disadvantageous, but, additionally, the reduced securement property of the ceramic solidified via the glass phase is also disadvantageous.
[0009] DE-A1 101 07 451 discloses a process for the production of an oxide ceramic shaped part that is formed from a zirconium or aluminum oxide ceramic via milling with a large CAD/CAM technology system after pre-sintering. Thereafter, the milled blank is sintered under no pressure at 1200 to 1650° C. The thus produced oxide ceramic phase exhibits a reduced translucence as compared to a high-temperature isostatically pressed ceramic, the mechanical properties are worse than those of a high-temperature pressed ceramic, and such ceramics are difficult to etch.
[0010] CH-A5 675 120 discloses zirconium oxide mixture ceramics, which comprise 7 to 12% by weight PiO 2 and other grain growth limiting and stabilization suitable additives. These can also comprise 0 to 30% by weight Al 2 O 3 . The powder mixture is sintered at a temperature from 1100 to 1300° C. The disadvantage of this ceramic is that the achievable thickness lies at only 98% of the theoretical thickness (TD) and, consequently, is less than that of a high-temperature pressed ceramic. The production of a retentive design on the outer surface is, with this ceramic, possible only with difficulty.
[0011] Additionally, the publication “Heiβisostatisches Pressen” from D. W. Hofer (Heiβisostatisches Pressen, in: Technische Keramische Werkstoffe, Fachverlag Deutscher Wirtschaftsdienst, Hrsg. Kriegesmann J., Kap. 3.6.3.0, pp. 1-15. January 1993) discloses that work pieces can be produced via high-temperature pressed processes in which the structures thereof scarcely exhibit any defect locations and the thicknesses of which are nearly those of the theoretically possible values. In order to achieve these properties, however, a pressure of between 30 to 200 MPa is required for the sintering temperatures. Moreover, an inert gas atmosphere follows the step of the pressure treatment. Correspondingly, this technique and the attendant hardware-intensive work require considerable effort and outlay. This process is thus disadvantageous in that it is costly and involves complicated processing technologies and their attendant high capital and energy costs so that, for example in connection with small enterprises, such as dental laboratories, it is not possible for such enterprises themselves to perform this process.
OBJECTS AND SUMMARY OF THE INVENTION
[0012] In contrast, the present invention offers a solution to the challenge of providing a method for the production of an oxide ceramic shaped part as well as an oxide ceramic shaped part itself, that is more suitable for the realization of a dental restoration piece and that permits a cost-optimized production with a simultaneously improved aesthetic appearance without degrading the use properties of the thus-produced shaped part and offering, especially, the possibility to produce a retentive design and to ensure the securement of the shaped part on the natural tooth.
[0013] Surprisingly, the inventive configuration of an infiltration coating or covering on the relevant regions of the oxide ceramic part permits the realization of an increased securement of the entire oxide ceramic part. Evidently, the covering, or the at least partial covering of the oxide ceramic part with the coating imparted by the infiltration, stabilizes the oxide ceramic shaped part to such an extent that a clearly improved fracture strength approaching 6.5 MPa m 1/2 can be achieved.
[0014] In a surprising manner, the inventive solution also leads to an improvement of the aesthetic appearance of a dental restoration piece if the inventive oxide ceramic shaped part is used as the dental restoration piece. The infiltration coating has a higher translucence while the infiltration-free inner region or core of the oxide ceramic has a reduced translucence and, in connection with the realization of a zirconium oxide ceramic, the coating is practically white. This simulates the human tooth in a surprisingly simple manner and is achieved without any need to deploy mixture ceramics, if such is desired.
[0015] Due to the possible or optional omission of an additional mixed ceramic, the therewith connected problems also drop out such as the longer process time, the securement problems, and the required coating thickness of the mixture ceramic. In contrast, the inventive solution is suitable for the realization of small-scale or closely-spaced members, yet nonetheless aesthetically very attractive, dental restoration pieces. In particular, if the infiltration coating comprises a silicate phase, this can, for example, be etched away with HF and an adhesive binding with other work pieces can be realized.
[0016] The inventive solution permits, in a surprisingly simple manner, the achievement of the same securement properties that can be achieved with hot isostatic presses, whereby the time consuming hot-press process can be avoided. The biaxial securement property is, in connection with one embodiment of an oxide ceramic connection part, not less than 800 MPa. The fracture mechanism properties of the pure crystalline oxide ceramic phase are approximately 6.95 MPa m 1/2 , as determined in accordance with the Indenter process and calculations in accordance with Evans & Charles critical tension intensification factors IIC and, in fact, lie comparatively higher than even those of corresponding high-temperature pressed ceramics. It is surprising in this connection that the properties of the hot-pressed materials, even those with predominantly tetragonal zirconium oxide as the crystalline oxide ceramic phase, have been duplicated. Preferably, the thickness of the inventive infiltration coating is between 2 to 30%; in an advantageous configuration between 5 and 20%; and, for practical purposes, between approximately 10 to 15%, each respective selected thickness being a function of the respective largest diameter of the oxide ceramic part.
[0017] The coating that at least partially covers the core formed of a non-metallic, inorganic phase is relatively less resistant to acids than the pure crystalline oxide ceramics in the core. The coating can thereby be easily etched. The chemical resistance is, however, not substantially less than that of the core, if the covering coating comprises only micro-crystal zirconium oxide.
[0018] Due to the reduced chemical resistance of the coating that at least partially covers the core, a retentive design can be achieved there at via etching. The depth of this retentive design can be determined via the etching means, its concentration and the application time during the etching process. This depth corresponds in an inventive manner to, at the most, the thickness of the covering coating, as the core is substantially more resistant to chemical attacks than the covering coating.
[0019] In the realization of the inventive process, a pre-sintering to achieve 50% of the theoretical thickness in atmospheric air is undertaken at no pressure following the pressing of the oxide ceramic blank. In the realization of the inventive process, a powder or a powder mixture is provided as the outlet material, which is formed out of the corresponding oxide ceramic or mixture ceramic. The powder is preferably in the form of a granulate and is mixed with a binding material. Preferably, the binding material can be comprised of ethylene wax material, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetate, polyvinyl butyral, or cellulose.
[0020] The pre-sintering temperature amounts to clearly less than the sintering temperature and can lie, for example, between 600 and 1300° C. and, preferably, between 1000 and 1200° C.
[0021] To achieve the inventive solution, it is advantageous to evacuate the partially sintered part. In this connection, in accordance with the invention, less than 50 mbar, such as, for example, 20 mbar, is preferred. The low pressure is applied, for example, for 1 minute up to 4 hours such that a pressure equalization in the sense of the formation of a vacuum in the interior of the partially sintered oxide ceramic shaped part is formed. In connection with this evacuation, the gases are removed from the porous, partially sintered in-process part body. During this time, the inventive sol. to be deployed for preparing the further materials that are to be formed, is mixed. In a conventional manner, the formation of these further materials is undertaken following the evacuation in a low pressure atmosphere.
[0022] It is particularly advantageous, in connection with the inventive method, that the penetration of a precursor of a non-metallic, inorganic phase has shown its worth, such precursor comprising, for example, a precursor of a vitreous-amorphous phase and a solvent.
[0023] In accordance with the present invention, it is particularly advantageous if the infiltration material is available as a sol. and is further reacted into a gel. These are preferably precursor products of a glass or ceramic material. Via the low pressure, the mixed sol. is suctioned into the low pressure chamber and there follows a penetration over an inventive, decidedly short time, such as, for example, preferably, 1 minute. In this manner, there is achieved an infiltration coating with the desired coating thickness, which permits the setting or adjustment thereof via the infiltration time, the viscosity of the solution, but as well, the porosity of the partially-sintered ceramic part.
[0024] Surprisingly, the formation of the infiltration coating in a simple manner permits the realization of a decidedly uniform coating. Due to the short infiltration time, the infiltration fluid only has time for the outer surface of the in-process part body to be covered. Via aeration of the low pressure chamber, the infiltration material is practically suctioned in. It is to be understood that the viscosity of the preferably gel-formed infiltration material substantially influences the penetration depth. A reduced viscosity produces, due to the reason of the capillary working of the pores of the in-process part body, a large coating thickness of the infiltration coating, while a high viscosity reduces the penetration depth. Preferably, the coating thickness amounts to approximately 0.5 mm. In a modified embodiment, the coating thickness of the infiltration coating is approximately 1.5 mm, which corresponds to the coating thickness of the dental enamel, but this coating thickness can be adjusted to more or less, as well.
[0025] Immediately after this step, there follows an aeration of the low pressure chamber and the solidification of the applied solution into a gel is undertaken via heating at the pre-selected sintering temperature in an ambient atmosphere. The sintering temperature is, for example, 1300 to 1550° C. and the sintering follows under an ambient pressure at an ambient atmosphere. Via the inventive process, the sintering properties of the pure crystalline oxide ceramic phase are improved while, via a covering coating formed from a non-metallic, inorganic phase of the previously evacuated, partially-sintered shaped part, the penetration of gases into the porous structure of the partially-sintered part is prevented, whereby a complete dense sintering of the ceramic is achieved.
[0026] The inventive oxide ceramic shaped part can be pre-pressed in a desired form. It is also, however, possible to undertake a milling or another type of cutting or machining in order to produce a shaped part from the ceramic in-process part body and, in fact, to accomplish such, either after the pre-sintering or after the sintering. With respect to such an undertaking after the pre-sintering, the advantage is gained that the shaping is possible in a relatively easy manner in that the final hardness has not yet been reached. In contrast, in connection with such an undertaking after the sintering, a very hard work piece such as a diamond-cutting disc must be used whereby, to be sure, the shape integrity is not degraded by a further shrinking process.
[0027] In accordance with the present invention, an oxide ceramic shaped part with a theoretical thickness of 99.9% is produced via, for example, sintering at 1480° C., whereby it is advantageous that, during the sintering in an ambient atmosphere, the shaped part is worked so that the shrinkage factor is less than that of a high-temperature isostatic press process.
[0028] The inventive process permits the preparation of a substantially tetragonal phase with reduced cubical phase components, provided that a sintering temperature of 1500° C. is not exceeded. In accordance with the present invention, in a surprising manner, a translucence profile is realized that heretofore could only be realized via a hot-press process. Additionally, in contrast to a hot-press ceramic, the advantage is obtained that an adhesion via etching on the infiltration coating is possible without further effort.
[0029] The present invention is particularly advantageous in connection with zirconium oxide ceramic or mixture ceramics having a high zirconium oxide portion, whereby, as well, suitable doping—such as with yttrium—and mixing—in can be advantageous. In connection with such hard ceramics, the bending strength in the core is high, the fracture strength, in contrast, is particularly good in the infiltration coating, which is formed from the crystalline oxide ceramic phase and the infiltration phase that penetrates the crystalline oxide ceramic phase—also called infiltration.
[0030] The thus-produced inventive oxide ceramic composite shaped part comprises, consequently, in its pure crystalline oxide ceramic core, the optical and mechanical properties which even equal the values of those properties in the high-temperature isostatic pressed materials. The properties of the pure crystalline oxide ceramic phase are, evidently, realized by the reason of the thickness of the structure.
[0031] In one embodiment, following the finish sintering, there is effected, to inventively produce an oxide ceramic composite shaped part, a process in which a material reduction working occurs that is, preferably, performed by CAD/CAM technology. In this connection, the covering coating is completely or partially reduced away and the translucent core comes to the outer surface. In this manner, the final shaping of the oxide ceramic composite shaped part can subsequently occur. If the covering coating remains in a partially covering manner on the outer surface, this can be removed in a following step via etching.
[0032] A retentive design can be maintained in the regions where the outer coating still remains. At the same time, a thick, translucent structure appears on those portions of the outer surface at which the coating has been removed. In this manner, there is produced, in a surprisingly simple manner, an aesthetic appearance that corresponds to that produced in connection with comparable hot isostatic press work pieces. Due to the high density of the structure, a high light transmission capability (translucence) is achieved that corresponds to that of hot isostatic pressed ceramic.
[0033] To configure a dental restoration piece, a single coat mixture is subsequently applied in order to produce an even more improved aesthetic appearance. In the regions in which a retentive design was produced, the use of suitable desired adhesive systems is possible. Preferably, an adhesive system is deployed. In accordance with the present invention, an adhesive securement is possible in a surprisingly simple manner which is not possible with respect to corresponding hot isostatic pressed work pieces. In connection with the securement materials, chemical, light-hardenable, or dual hardenable material are preferred. Cementing materials are, for example, zinc phosphates. The inventive oxide ceramic composite shaped part offers, in this manner, an improved adhesive procurement possibility with the same aesthetic appearance as hot isostatic pressed, comparable materials. Moreover, the sintering process is substantially simpler and is, consequently, in contrast to the hot isostatic press process, considerably more cost favorable.
[0034] The inventive solution permits a plurality of oxide ceramic parts to be produced. In this connection, dental restoration pieces are produced such as inlays, onlays, crowns, partial crowns, veneers, facets, bridges, caps, brackets and abutments, but also alluvial materials, and alluvial material components and frameworks.
[0035] Also, it is basically possible to exploit the advantages of the inventive process in connection with other deployed ceramic pieces such as, for example, the preparation of synthetic joints, whereby the outer surface infiltration coating offers favorable properties in view of the reduced abrasion with, at the same time, good hardness and a glass-hard outer surface; however, surgical implants or components thereof are equally amenable to such preparation. Also, endodontic parts such as root posts can be produced by the inventive process whereby the good adhesion on other parts can be exploited.
[0036] The length of time of the production of an inventive ceramic blank is strongly dependent upon the length of time required for the desiccation—that is, the creation of the low pressure environment. The preparation of the infiltration material requires, in connection with one advantageous embodiment of the invention, a not inconsiderable mixing time and standing time. The determination of the time frame can, however, be favorably influenced by the mixing of the infiltration material already before the process has begun—that is, for example, while the blank is pressed or, at the latest, during the pre-sintering, so that this mixing time does not add onto the cycle time for the preparation of a finished oxide ceramic part.
[0037] The pure infiltration time can, for example, amount to 1 or 2 minutes and can last, in any event, typically less than 10 minutes while the finish infiltration occurs in accordance with the respective selected temperature curve of, for example, 30 to 60 minutes.
[0038] Further advantages, details, and features are described in the hereinafter following descriptions of several embodiments of the present invention with reference to the drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0039] FIG. 1 is a schematic perspective view of an arrangement for performing the inventive infiltration method for preparing an infiltration coating on an oxide ceramic part;
[0040] FIG. 2 is a graphical view of the infiltration coating thickness versus the infiltration time;
[0041] FIG. 3 is a schematic perspective view of a sintering oven for use in connection with the inventive infiltration method for preparing an infiltration coating on an oxide ceramic part;
[0042] FIG. 4 is a flow chart of the steps of one implementation of the method of the present invention; and
[0043] FIG. 5 is a flow chart of the steps of another implementation of the method of the present invention.
DETAILED DESCRIPTION
[0044] FIG. 1 schematically illustrates an arrangement for performing the inventive infiltration method for preparing an infiltration coating on an oxide ceramic part. The blank 10 , which subsequently forms the oxide ceramic part, is pre-sintered and is disposed in a beaker 12 . The beaker 12 is disposed in a desiccator 14 on whose cover a drip funnel 16 is mounted.
[0045] Moreover, the desiccator comprises, in a conventional manner, a low-pressure connection hose 18 that is connected with a low-pressure pump. In a conventional manner, the polished sealing edge 20 of the desiccator closes upon the creation of a low pressure environment in the desiccator and can be opened after the venting of the desiccator. The drip funnel does not have a pressure compensation but is, however, provided with a stopcock 22 that permits a fine adjustment of the drip rate.
[0046] The infiltration is effected in a manner such that a prepared brine 22 is introduced as the infiltration material into the drip funnel 16 , after which the desiccator 14 is brought to a low pressure of, for example, 20×10 −3 bar.
[0047] As soon as the desired pressure is reached, the stopcock 22 is opened in the desired manner. The beaker 12 is filled up to a maximum fill level 24 with infiltration material that later penetrates into the blank 10 . The penetration is effected principally from the topside and the side walls while the underside, which is disposed on the beaker 12 , is somewhat less strongly infiltrated.
[0048] Although FIG. 1 illustrates a cylindrical blank 10 , it is to be understood that, in practice, predetermined shaped parts are produced which are disposed on the base of the beaker 12 and are wetted with infiltration material. After an infiltration time of 1 minute, an infiltration coating in a thickness of 0.3 to 0.6 mm has already been formed therefrom.
[0049] FIG. 2 is a graphical illustration of the infiltration coating depth as a function of the infiltration time. In accordance with the present invention, it is advantageous that the coating thickness in many regions can be accommodated to the requirements. Thus, very fine-sectioned and thin oxide ceramic parts with a decidedly low infiltration coating thickness which, however, offers a certain translucence but, as well, offers a good securement of the core, can also be worked.
[0050] It is advantageous, for example, in connection with an infiltration depth of 1 mm or somewhat less, to simulate the natural tooth enamel. The preferred region for the infiltration depth is, however, greater than 0.4 mm.
[0051] FIG. 3 is a schematic illustration of a sintering oven 26 . The sintering oven comprises a plurality of heating elements 28 and a crucible 30 that receives therein the blank 10 after infiltration. Preferably, in a conventional manner, the crucible is provided with a powder coating and there follows a heating or a finish infiltration of the blank 10 to form the oxide ceramic part within less than 1 hour, including the heating up time.
[0052] In the hereinafter following descriptions, various embodiments are described in more individual detail.
EXAMPLE 1
[0053] A dry press granulate of ZrO 2 powder is used for the raw material for the blank 10 . It is doped with yttrium and comprises other components such as Al 2 O 3 . The dry press granulates can be, for example, those available from the TOSOH company with the commercial designation TZ-3YB and TZ-8YB and having a primary crystal size of 280-400 nm and a granulate size of 50 μm but, as well, can be the granulate available under the commercial designation of TZ-3Y20AB that is characterized by the addition thereto of 20% Al 2 O 3 and that otherwise corresponds to the other granulates.
[0054] In accordance with the following table, powdery oxidized raw materials in predetermined mole portions are added to the zirconium oxide ceramics.
Raw Material TZ3YB TZ3YB TZ3YB TZ3YB TZ8YB TZ8YB TZ8YB Oxide CeO 2 /mol-% 2.5 5 8 10 15 — — Er 2 O 3 2.5 5 — — — — — CeO 2 + Er 2 O 3 /mol-% 3 + 3 — — — — — — Sc 2 O 3 /mol-% 3 — — — — — — TiO 2 /mol-% 10 15 — — — 10 15
[0055] In this inventive experiment, cylindrical press forms with inner diameters of 12 and 16 mm were used. The pressing of the blank 10 was effected in a conventional manner with pressures of 500, 600 to 1100 bar, whereby the press pressure was reached in 5 seconds, then held for 15 seconds at the maximum pressure, and then reduced within a further 5 seconds.
[0056] Thereafter, there followed the pre-solidification step during which, at the same time, the release was effected and this is shown in the following table, which shows the serially following time segments of the pre-sintering process with the slopes indicated in the left hand column.
° C. Rn / ° C. Rn + 1 / Heat rate/ Slope ° C. ° C. K min −1 K h −1 Time/min Time/h 1 0 320 2.5 150 128 2:08 2 320 470 1 50 150 2:30 3 470 1100 2.5 150 252 4:12 4 1100 1100 0 0 20 0:30 560 9:20
The powder comprises a binder in the form of a press assistance material and, via the dry pressing in the following bond release, the introduced binding material was burnt out and the blank was thus formed with a porous structure. Thereafter, the pre-sintering was performed. After the pre-sintering, a part with 50% thickness depth (TD) was achieved.
[0057] The evacuation of the blank 10 was performed in the desiccator 14 with a finish pressure of approximately 20 mbar. Due to the comparatively long evacuation time, which, in any event, amounted to more than 1 hour, the gas enclosed in the porous blank was substantially removed.
[0058] Infiltration material based upon tetraethoxysilane/tetraethylorthosilicate (TEOS) was used. TEOS was, together with water with a catalyst of aluminum nitrate nonhydrate(Al(NO 3 ) 3 )×9 H 2 O), mixed with a sol. As a function of the mixing time and the subsequent standing time, the sol. reacted slowly into a gel and condensed into a glass-similar structure. Cerium nitratheydrate was also introduced to the actual catalyst.
[0059] It was attempted to prepare the infiltration material so that, after the infiltration into the infiltration coating, a firm gel was quickly formed which converted after the sintering into a silica glass phase. The infiltration coating was comprised, in accordance with the invention, principally of tetragonal crystalline zirconium oxide phases as well as an amorphous glass phases, substantially from condensed TEOS, while the core of the inventive oxide ceramic piece was substantially comprised of zirconium oxide with the previously noted doping, which was, in any event, predominantly in tetragonal phase.
[0060] The attempts with various mixing relationships of TEOS, (Al(NO 3 ) 3 )×9 H 2 O) as well as Ce(NO 3 ) 3 ×9 H 2 O revealed the tendency, in connection with longer mixing times, that the solidification time—that is, the standing time until solidification—decreased. The sums or totals of the times amounted to typically 6 to 7 hours, whereby the omission of the cerium nitratehydrate in certain mixing relationships was able to produce solidification after a mixing time of 3 hours.
[0061] The prepared infiltration material was then introduced into the drip funnel and the stopcock 22 was opened and, in fact, was opened to the extent that the blank was, in any event, fully covered following the introduction of the sol., but not so far as to permit an excess of infiltration material to flow through the drip funnel, as such would have delayed the venting of the desiccator.
[0062] The venting followed the complete opening of the stopcock, after which the drip funnel 16 became empty.
[0063] The infiltration material that had been introduced through the desiccator and thereafter placed under low pressure initially foamed, whereby the low pressure was maintained.
[0064] As can be seen in FIG. 2 , the infiltration depth is dependent not only upon the viscosity of the introduced infiltration material but, as well, is, in particular, dependent upon the mixing time and the standing alone time of the infiltration material (the difference between ZIO15 and ZIO16b).
[0065] It is contemplated that the time for the process is to be selected such that the solidification of the infiltration material occurs after or during the infiltration. It is not critical if the infiltration material has already solidified, whereby, as well, in connection with fluid infiltration material, a thickening of the coating is anticipated in that, as well, a fluid infiltration material closes the pores of the blank 10 .
[0066] Infiltration material remainders on the ceramic blank were then removed easily with a towel and there followed an air-drying step, whereby the inventive examples were subjected to an air-drying of 1 to 2 hours.
[0067] The finished sintering followed in the same sintering oven which had been deployed for the pre-sintering and the sintering curve is shown in the following table in 3 time segments.
° C. Rn / ° C. Rn + 1 / Heat rate/ Slope ° C. ° C. K min −1 K h −1 Time/min Time/h 1 0 1000 5 300 200 3:20 2 1000 1480 2.5 1450 192 3:12 3 1480 1480 0 0 30 0:30 422 7:02
[0068] In this connection, the blank was sealed in a quartz frit—or Al 2 O 3 —powder bed in an aluminum oxide crucible.
[0069] The results showed that the sintered blank comprises an infiltration coating thickness which, in dependence upon the infiltration time, is of varying thickness.
[0070] There was also obtained a good translucence of the oxide ceramic part and, in the interior of the blank, a tetragonal phase with an average crystal size of 0.4 to 0.5 micrometers was present.
[0071] The smallest achieved infiltration depth, in connection with the above-noted infiltrate based upon TEOS, amounted to approximately 180 micrometers.
EXAMPLE 2
[0072] In a modified example, in lieu of TEOS, a zirconium (IV) propylate (Zr(IV)Pr) was deployed. This zirconium (IV) propylate was used in lieu of TEOS and, when subjected to atmospheric pressure with water, was driven as zirconium oxide particles out of the pores of the blank. Also, in this connection, the pores could be closed, whereby the crystalline particles in the pores precipitate out, which corresponds to the actual base material. The thus achieved minimal coating thickness of the infiltration coating amounted to approximately 50 micrometers.
EXAMPLE 3
[0073] In total, the inventive process produced an oxide ceramic composite shaped part with high fracture strength, whereby the translucence properties corresponded to those of zirconium oxide ceramic (TZP) which are deployed in connection with the high-temperature isostatic press process.
Density Light K ic -Value (in the Transmission (Evans & Ptr/ t Inf. / (core)/ Capability HV 10/ Charles)/ Sample bar min V Br /C g cm −3 (comparison) % MPa MPa m 1/2 A1235 1000 1 1480 6.08 70.7 — — A1237 1000 5 1480 6.10 75.0 — — A1240 1000 2 1480 — — 13220 6.95 A1245 900 1 1480 — — 13055 6.55 A1246 900 1 1480 6.08 72.2 — — Mexoxit unknown unknown unknown 6.07 70.3 12850 6.65 Bio-HIP ZeO 2 (comparison measurement) Denzir unknown unknown unknown 6.10 76.4 12830 6.70 DO HIP-ZrO 2 (comparison measurement) A1253 900 Not 1480 5.88 56.4 — — infiltrated A1254 900 Not 1480 — — 12900 6.17 infiltrated
[0074] As can be seen in the foregoing, it is clear that the conventional sintered examples not produced in accordance with the present invention exhibit considerably worse properties with respect to light transmission capability and fracture strength.
EXAMPLE 4
[0075] Additionally, several attempts were made in connection with the inventive process to effect the etching with HF and an etching retentive design was produced in correspondence with the length of time. Etching attempts were undertaken by which the outer coating was completely etched away and only the inner oxide ceramic core remained. By covering the infiltration coating with wax or a polymer coating, it is also possible that selected locations can remain unetched.
EXAMPLE 5
[0076] In correspondence with the above noted type and manner of shaped part handling, a cylindrical part with a diameter of 12 mm and a height of 25 mm was produced via pressing of a granulate obtained from the Tosoh company (TZ 3YB) and subsequent pre-sintering at 1100° C. To perform thereafter a shaping of the part, a CEREC Inlab milling machine available from the Sirona Company was deployed, whereupon the thus-produced shaped part was a crown having excess material. The excess material had to be removed so that, following the shrinking which occurs in connection with the sintering and the partial etching away of the covering coating, an optimal size accommodation or fitment to the model frame was be produced. In accordance with the present invention, the thus obtained partially sintered and milled part was then provided with a covering coating in a vacuum-configured environment, whereby the applied material generally penetrated into the outer surface of the porous partially sintered part. During the subsequent sintering process in ambient air at ambient pressure, a finished sintered crown was produced that, following partial etching away of the covering coating, exhibited, on the one hand, a retentive design and, on the other hand, a good size accommodation or fitment to the model frame.
[0077] FIGS. 4 and 5 each show respective illustrations of the results of the process steps in various configurations of the inventive method. The thus-depicted configurations of the inventive method differ from one another with respect to the timing of the machining or trimming step: with respect to the configuration “Technology II” depicted in FIG. 5 , the machining or trimming step is performed before the infiltration step while, with respect to the configuration “Technology I” depicted in FIG. 4 , the trimming step is performed after the finish sintering step. The respective configuration of the inventive method shown in FIG. 4 requires greater tooling efforts in view of the high degree of securement of the substantially completely finished sintered dental restoration piece; however, this configuration of the inventive method offers a somewhat greater degree of precision.
[0078] In all, the demonstrations conducted with respect to the inventive method resulted in an oxide ceramic part having a high fracture strength of 6.95 MPa m 1/2 , whereby the translucence properties were correspondingly satisfactory and corresponded to those of oxide ceramic parts that have been produced by high-temperature isostatic press processes.
[0079] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. While a preferred form of this invention has been described above and shown in the accompanying drawings, it should be understood that applicant does not intend to be limited to the particular details described above and illustrated in the accompanying drawings, but intends to be limited only to the scope of the invention as defined by the following claims. In this regard, the term “means for” as used in the claims is intended to include not only the designs illustrated in the drawings of this application and the equivalent designs discussed in the text, but it is also intended to cover other equivalents now known to those skilled in the art, or those equivalents which may become known to those skilled in the art in the future.
|
A method for producing an oxide ceramic shaped part includes pressing a powder provided with a binding material or a powder mixture of an oxide ceramic into a shaped part, pre-sintering the shaped part at substantially atmospheric pressure and a temperature of 600 to 1,300° C., and evacuating a closed container in which the pre-sintered shaped part is disposed with the shaped part having a maximum density of 10 to 90%. The container is at an absolute pressure of less than 40 mbar. Subsequently, an infiltration material is applied onto the shaped part via infiltration with the infiltration material operating to seal off the shaped part relative to the surrounding atmosphere. The length of time of the infiltration is preferably 1 to 10 minutes.
| 8
|
FIELD OF THE INVENTION
[0001] The invention pertains to plastic bags and methods of manufacturing them. More particularly, the invention relates to square bottomed bag stacks supplied with a detachable header portion for suspending the bag stack as well as t-shirt style handle bags.
BACKGROUND OF THE INVENTION
[0002] Plastic bags have replaced paper bags for many applications in recent years based upon the ease and economics with which they can be manufactured. However, at present, paper bags are still favored for certain applications. Paper bags can easily be constructed with a completely flat bottom and can be made to stand up without a supporting rack both when empty and when filled. Also, paper bags tend to be somewhat porous and “breathable” and thus more desirable for use with items such as hot food products. For these reasons, paper bags have dominated such industries as fast food delivery and other applications in which it is important to be able to easily position articles within the bag. Paper bags, on the other hand, have other problems. For example, strong handles are not easily attached to paper bags, the bags become weakened with moisture, they are heavy, bulky and require wood as raw material. Plastic bags, on the other hand, are more durable, more compact and light weight, stronger, impervious to moisture and can easily be made with strong handles.
[0003] Various designs have been developed in attempts to provide a practical, breathable, square bottomed plastic bag that will stand up when opened for filling and remain upright when filled. U.S. Pat. No. 6,286,681 issued to Wilfong, Jr. et al. is directed to a ventilated plastic bag embodying closely spaced micro-perforations that extend through the wall sections to provide ventilation to the interior food carrying area. These perforations allow the bag to be used for carrying hot food items without weakening the strength regions of the bag. The closed bottom area of the bag may be formed by heat-sealing of the film material, but may also include corner or angle seals to define a square bottom on the bag.
[0004] U.S. Application Publication No. 2002/0110290 by Gebhardt discloses a plastic bag with randomly placed arcurate vent pairs. The bags described in this publication are made from a plastic tubing or sheeting stock. The bag may also include a handle aperture and the bag may include square-bottomed seals on gusseted bags. In the preferred embodiment of the receptacle described, vents are cut into the material of the receptacle that can accommodate, store, and transport fresh hot foods to provide a breathable element desired for the bags.
[0005] U.S. Pat. No. 6,319,184 issued to DeMatteis is directed to an apparatus and process for producing cold seal in plastic bags. The bags described may be of a semi-flat-bottom type and may have hand holes to form handles in the upper portion of the bags. U.S. Pat. No. 6,113,269 issued to DeMatteis discloses an automatic ventilating system for plastic bags. U.S. Pat. No. 6,095,687 issued to DeMatteis is directed to a flat bottomed plastic bag having a handle aperture. The bag described sits upright upon a bottom gusset.
[0006] U.S. Pat. No. 5,149,201 issued to Benoit discloses a bag structure of a thermoplastic film material comprising front and rear bag walls connected by side walls and having an open mouth top portion, said open mouth portion being characterized by having handles located at opposite end regions thereof, said handles being of two films as a result of being integral extensions of said front rear and gusseted side walls, said bag having a bottom wall planarly extensible so as to form a rectangle with at least no substantial excess film outside of the bulk volumetric capacity of said bottom region of said bag. This invention also provides a method and system for preparing flat bottom thermoplastic sacks comprising process steps and means for forming a tube of thermoplastic film, collapsing said tube while forming two oppositely disposed gussets therein, forming two pairs of diagonal sealed seams in the gussets, forming a transverse sealed seam across the tube along a line which includes the inboard ends of the diagonal seams and forming pre-weakened transverse lines closely adjacent to said transverse sealed seam or forming a severing line along this line, removing the four double triangular regions bounded by the diagonal seams, the transverse seams and the side edges of the tube and collecting the resulting structures either while still interconnected or by stacking the severed sacks. The final structure can have handles or it can be handleless.
[0007] U.S. Pat. No. 5,165,799 issued to Wood describes flexible square bottom bags which include side gusset panels having central inwardly oriented fin seams and which are sealed adjacent their lowermost corners to portions of the front and rear panels of the bags and wherein the entire width of the lowermost edges of the front and rear panels are sealed to thereby form bags having bottoms reinforced by triangular gusset seals at each corner and which have an outwardly oriented transverse bottom fin seam when erected.
[0008] U.S. Pat. No. 5,362,152 issued to Fletcher et al. describes a T-shirt type plastic bag adapted for carrying hot foods from fast food restaurants. The bag includes front and rear wall sections, gussetted side wall sections integrally connecting the front and rear wall sections together and means connecting the bottoms of the front, rear and gussetted side wall sections together to define a closed bottom. At least a part of the front and rear wall sections are open at the tops to define a mouth portion. Laterally spaced handles are integral with the front, rear and gussetted side wall sections and extend upwardly from opposed sides of the mouth portion. Apertures extend through at least one of the wall sections for providing a path for a venting air flow from the outside of the bag and through the inside of the bag when the bag is carrying hot food.
[0009] U.S. Pat. No. 5,102,384 issued to Ross et al. discloses a method of constructing a flat bottom in a plastic film tube having an open upper end, a closed lower end formed by a transverse seal, forward and rearward sides and a pair of opposing pleated sides that interconnect the forward and rearward sides. The method includes the steps of releasably engaging a lower vacuum and a lower clamp with a transverse section of the rearward side of the tube to provisionally hold the transverse section. A lateral section of the forward side is gripped and raised by an upper vacuum and an upper clamp to expose a portion of the pleated sides such that first and second pockets are formed, respectively, in the sides. The sealed lower end is drawn toward the upper end to fold the tube along first and second transverse fold lines in the forward side, along a third transverse fold line in the transverse section of the rearward side, and along fourth and fifth fold lines, respectively, in the pleated sides such that the first and second pockets are located in the pleated sides, respectively between the first and third fold lines and the lower end of the bag. Pressure is applied to the tube to form creases along the first, third, fourth and fifth fold lines, which define the perimeter of the flat bottom of the tube.
[0010] U.S. Pat. No. 5,549,538 issued to Marsik describes a process for manufacturing a multi-ply square bottom bag having a front wall, a back wall, a pair of gusseted side walls, each of which join to said front and back walls. There is also formed a gusseted square bottom panel having spaced but substantially parallel gusset edges and said bottom is joined to the front, back and side walls. The bag is produced by providing a web of inner ply material and a web of outer ply material, adhesively joining said webs into a composite and forming said bag from said joined webs. The improvement relates to forming a first flap in the inner web by cutting the web so as to form a plurality of free edges and a hinge line for said flap. The hinge line is connected to the free edges so that the free edges and hinge line define the flap. Thereafter joining the inner and outer webs to form the composite web. The hinge line is generally transverse to the longitudinal axis of the web and the flap is formed in the inner web so as to be positioned adjacent the front wall and bottom wall with the hinge line at the junction thereof when said bag is formed and said flap is arranged to overlie the gusset edges in the bottom panel.
[0011] It is an objective of the present invention to provide a registered bag stack with attached headers for suspension from a dispensing rack. It is an additional objective to provide a registered bag stack with integral t-shirt style handles formed in an upper portion of the bag. It is a further objective to provide square bottomed bags that will remain upright when opened in filled or unfilled condition. It is a still further objective of the invention to provide a breathable or ventilated bag suitable for use with hot food or similar items. It is yet a further objective to provide a bag stack that has the above-described features that is easily and inexpensively manufactured.
[0012] While some of the objectives of the present invention are disclosed in the prior art, none of the inventions found include all of the requirements identified.
SUMMARY OF THE INVENTION
[0013] The present invention addresses all of the deficiencies of prior art square bottom bag stack inventions and satisfies all of the objectives described above.
[0014] (1) A square bottomed plastic bag stack providing the desired features may be constructed from the following components. A plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls have first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Each of the bags is folded inwardly at the side gussets and upwardly from either the front wall or the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. Each of the bags is attached at the top edges of at least one of the front and rear walls to at least one header strip. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.
[0015] (2) In a variant of the invention, a plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Lower corners of the each side gusset are folded outwardly and together to form downward pointing triangular panels. The triangular panels are folded inwardly from the side gussets. Lower portions of the front and rear walls are folded inwardly and sealed together to form the bag bottom. The bag bottom is sealed to the side gussets adjacent upper edges of the triangular panels. The triangular panels are sealed to an upper surface of the bag bottom. Each of the bags is folded inwardly at the side gussets and upwardly from either the front wall or the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.
[0016] (3) In a further variant, a plurality of stacked polyethylene film bags is provided. Each of the bags includes front and rear polyethylene film walls. Each of the front and rear walls has first and second side edges, a top edge and a bottom edge. Each of the bags has a pair of longitudinally oriented side gussets attached to the first and second side edges. Each of the bags has a crease line. The crease line is parallel to the bottom edges and spaced upwardly from the bottom edges by approximately one half of a width of one of the side gussets. Each of the bags is slit from the bottom edges of the walls to the crease line at each intersection of the front and rear walls and the side gussets.
[0017] Each of the bags has a flat, rectangular bottom formed of lower portions of the front and rear walls and lower portions of the side gussets. Lower corners of the each side gusset are folded outwardly to the crease line and together to form downward pointing triangular panels. The triangular panels are folded inwardly from the side gussets at the crease line. Lower portions of the front and rear walls are folded inwardly from the crease line and sealed together to form the bag bottom. The bag bottom is sealed to the side gussets adjacent the crease line and upper edges of the triangular panels. The triangular panels is sealed to an upper surface of the bag bottom. Each of the bags is folded inwardly at the side gussets and upwardly from either of the front wall and the rear wall at the crease line, to form a flattened bag. The bags are stacked upon one another and held in registration by attachment of the bags to one another, thereby forming a registered bag stack. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.
[0018] (4) In still a further variant, each of the bags is attached at the top edges of at least one of the front and rear walls to at least one header strip.
[0019] (5) (6) In yet a further variant of the invention, the header strip is attached at the top edges of at least one of the front and rear walls by at least one perforation.
[0020] (7) (8) In still another variant, the header strip has at least one hole for suspending the bags from a dispensing rack.
[0021] (9) (10) In yet another variant, the header strip includes at least one weakened area. The weakened area extends from the hole to an upper edge of the header strip.
[0022] (11) In a further variant of the invention, the square bottomed plastic bag stack includes means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. When the leading bag is pulled from the bag stack, the subsequent bag will cause the leading bag to open.
[0023] (12) In still a further variant, the means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack is selected from the group that includes glue spotting, corona treatment, pressure and corona treatment with pressure.
[0024] (13) (14) In another variant, the header strips are attached to one another with at least one hot pin extending through the headers to maintain the bags in registration.
[0025] (15) (16) In still another variant of the invention, the header strips are attached to one another with at least one cold stake extending through the headers to maintain the bags in registration.
[0026] (17) (18) In yet another variant, at least one handle opening is provided. The handle opening extends through the front and rear walls in an upper portion of each of the bags.
[0027] (19) In a further variant, the bags are formed of a porous material.
[0028] (20) In still a further variant, the bags are formed of material having microperforations penetrating at least a portion of any of the bag walls and side gussets.
[0029] (21) In another variant, the bags have a plurality of ventilating openings penetrating at least a portion of any of the bag walls and side gussets.
[0030] (22) In still another variant, an upper seal is provided. The upper seal joins the front wall to the rear wall at the top edges of the bag walls and joins top edges of the side gussets. A U-shaped cutout is provided. The cutout commences at a first point on the upper seal. The first point is spaced from the first side edge and extends downwardly toward the bottom edges, across an upper portion of the bag walls and upwardly to a second point on the upper seal. The second point is spaced from the second side edge, thereby forming an open bag mouth and a pair of bag handles terminating at the upper seal.
[0031] (23) In yet another variant, the bags are attached to one another with at least one hot pin extending through the bag handles to maintain the bags in registration.
[0032] (24) In yet a further variant, the bags are attached to one another with at least one hot pin extending through the upper portion of the bag walls to maintain the bags in registration.
[0033] (25) In still a further variant, the bags are attached to one another with at least one cold stake extending through the bag handles to maintain the bags in registration.
[0034] (26) In another variant of the invention, the bags are attached to one another with at least one cold stake extending through the upper portion of the bag walls to maintain the bags in registration.
[0035] (27) In yet another variant, the bags further comprise a pair of apertures, each of the apertures penetrating the bag handles at a point spaced downwardly from the upper seal, the apertures permitting the bag stack to be suspended from a dispensing rack.
[0036] (28) In still another variant, a central tab is provided. The central tab extends upwardly from at least one of the front wall and the rear wall at the open mouth. The central tab has an opening through it for suspending the bag stack.
[0037] (29) In a further variant, the central tab is attached to at least one of the front wall and the rear wall at the open mouth at a weakened area. The weakened area permits the central tab to be torn from the open mouth of the bag as the bag is removed from a dispensing rack.
[0038] (30) In still a further variant, the central tab includes a weakened area. The weakened area extends from the opening to an upper edge of the central tab. The weakened area parts under pressure as the bag is removed from a dispensing rack.
[0039] (31) In yet a further variant of the invention, at least one header strip is provided. The header strip is attached above the upper seal.
[0040] (32) In still another variant, the header strip is attached above the upper seal with at least one perforation.
[0041] (33) In still a further variant, the header strip has at least one hole therethrough for suspending the bag stack.
[0042] (34) In a further variant, the header strip includes a weakened area. The weakened area extending from the hole to an upper edge of the header strip. The weakened area parting as the bag is removed from a dispensing rack.
[0043] (35) A method of making a square bottomed plastic bag stack, includes the following steps. Extruding a tube of polyethylene material. Forming side gussets in the tube and flattening the tube. Cutting the flattened tube perpendicular to the side gussets to a first predetermined length, thereby forming a bag blank. The bag blank has front and rear walls, front and rear top edges, front and rear bottom edges, first and second side edges. Slitting the bag blank at intersections of the side gussets and the front and rear walls from the front and rear bottom edges upwardly for a first predetermined distance. Folding lower corners of the each side gusset outwardly and together to form downward pointing triangular panels. Folding the triangular panels inwardly from the side gussets. Folding lower portions of the front and rear walls inwardly. Sealing the front and rear wall together adjacent the front and rear bottom edges to form a bag bottom. Sealing the bag bottom to the side gussets adjacent upper edges of the triangular panels. Sealing the triangular panels to an upper surface of the bag bottom. Folding each of the bags inwardly at the side gussets and upwardly from either of the front wall and the rear wall at a point spaced upwardly from the bottom edge, to form a flattened bag. Stacking a plurality of the bag blanks in registration to form a bag stack.
[0044] (36) A variant of the method of making a square bottomed plastic bag stack, includes the following steps. Extruding a tube of polyethylene material. Forming side gussets in the tube and flattening the tube. Cutting the flattened tube perpendicular to the side gussets to a first predetermined length, thereby forming a bag blank. The bag blank has front and rear walls, front and rear top edges, front and rear bottom edges, first and second side edges. Forming a crease line in each of the bag blanks. The crease line is parallel to the bottom edges and spaced upwardly from the bottom edges by approximately one half of a width of one of the side gussets. Slitting each of the bag blanks from the bottom edges of the walls to the crease line at each intersection of the front and rear walls and the side gussets. Folding lower corners of the each side gusset outwardly to the crease line and together to form downward pointing triangular panels. Folding the triangular panels inwardly from the side gussets at the crease line. Folding lower portions of the front and rear walls inwardly from the crease line. Sealing the front and rear wall together adjacent the front and rear bottom edges to form a bag bottom. Sealing the bag bottom to the side gussets adjacent the crease line and upper edges of the triangular panels. Sealing the triangular panels to an upper surface of the bag bottom. Folding each of the bag blanks inwardly at the side gussets and upwardly from either of the front wall and the rear wall at the crease line, to form a flattened bag. Stacking a plurality of the bag blanks in registration to form a bag stack.
[0045] (37) A further variant of the method of making a square bottomed plastic bag stack includes the following steps. Prior to stacking the bag blanks, perforating the bag blank at a perforation line, the perforation line located at a second predetermined distance from the front and rear top edges. Cutting the bag stack above the perforation line to form a plurality of bag stack header strips. Attaching the header strips to one another to maintain the bags in registration. When the bags are pulled from the bag stack and opened, they will stand erect upon the flat bottom.
[0046] (38) A still further variant of the method of making a square bottomed plastic bag stack includes the following step of cutting at least one hole in the header strips for suspending the bags from a dispensing rack.
[0047] (39) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of forming at least one weakened area. The weakened area extends from the hole to an upper edge of the header strip.
[0048] (40) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. When the leading bag is pulled from the bag stack, the subsequent bag will cause the leading bag to open.
[0049] (41) Another variant of the method of making a square bottomed plastic bag stack includes the step of providing a means for attaching an upper portion of the rear wall of a leading one of the bags to an upper portion of the front wall of a subsequent bag in the bag stack. The means are selected from the following group that includes glue spotting, corona treatment, pressure and corona treatment with pressure.
[0050] (42) Still another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the headers to maintain the bags in registration.
[0051] (43) Yet another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the headers to maintain the bags in registration.
[0052] (44) A further variant of the method of making a square bottomed plastic bag stack includes the step of cutting at least one handle opening in the bag stack. The handle opening extends through the front and rear walls in an upper portion of each of the bags.
[0053] (45) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of forming the bags of a porous material.
[0054] (46) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of forming microperforations penetrating at least a portion of any of the bag walls and side gussets.
[0055] (47) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of forming a plurality of ventilating opening penetrating at least a portion of any of the bag walls and side gussets.
[0056] (48) Another variant of the method of making a square bottomed plastic bag stack includes the following steps. Prior to stacking the bag blanks, joining the front wall to the rear wall at the top edges of the bag walls and joining top edges of the side gussets, thereby forming an upper seal. Forming a U-shaped cutout. The cutout commences at a first point on the upper seal spaced from the first side edge and extends downwardly toward the bottom edges, across an upper portion of the bag walls and upward to a second point on the upper seal spaced from the second side edge, thereby forming an open bag mouth and a pair of bag handles terminating at the upper seal.
[0057] (49) Still another variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the upper portion of the bag walls to maintain the bags in registration.
[0058] (50) A further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one hot pin through the bag handles to maintain the bags in registration.
[0059] (51) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the upper portion of the bag walls to maintain the bags in registration.
[0060] (52) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of driving at least one cold stake through the bag handles to maintain the bags in registration.
[0061] (53) Another variant of the method of making a square bottomed plastic bag stack includes the step of cutting a pair of apertures. Each of the apertures penetrate the bag handles at a point spaced downwardly from the upper seal. The apertures permit the bag stack to be suspended from a dispensing rack.
[0062] (54) Still another variant of the method of making a square bottomed plastic bag stack includes the step of forming a central tab. The central tab extends upwardly from at least one of the front wall and the rear wall at the open mouth. The central tab has an opening through it for suspending the bag stack.
[0063] (55) Yet another variant of the method of making a square bottomed plastic bag stack includes the step of forming a weakened area. The weakened area attaches the central tab to at least one of the front wall and the rear wall at the open mouth. The weakened area permits the central tab to be tom from the open mouth of the bag as the bag is removed from a dispensing rack.
[0064] (56) A further variant of the method of making a square bottomed plastic bag stack includes the step of forming the central tab with a weakened area. The weakened area extends from the opening to an upper edge of the central tab. The weakened area parts under pressure as the bag is removed from a dispensing rack.
[0065] (57) Still a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching a header strip above the upper seal.
[0066] (58) Yet a further variant of the method of making a square bottomed plastic bag stack includes the step of attaching the header strip above the upper seal with at least one perforation.
[0067] (59) Another variant of the method of making a square bottomed plastic bag stack includes the step of cutting at least one hole through the header strip for suspending the bag stack.
[0068] (60) A final variant of the method of making a square bottomed plastic bag stack includes the step of forming a weakened area. The weakened area extends from the opening to an upper edge of the header strip. The weakened area parts as the bag is removed from a dispensing rack.
[0069] An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment.
DESCRIPTION OF THE DRAWINGS
[0070] FIG. 1 is a perspective view of a gusseted open mouth bag with bottom seal;
[0071] FIG. 2 is a perspective view of the FIG. 1 embodiment with the bag sides pulled outwardly to form bottom edges;
[0072] FIG. 3 is a perspective view of the FIG. 1 embodiment illustrating a flattened bag bottom;
[0073] FIG. 4 is a perspective view of a second embodiment of bag formed from a section of gusseted tubing illustrating slitting of lower corners of the tube;
[0074] FIG. 5 is a perspective view of the FIG. 4 embodiment illustrating the outward folding of lower ends of the side gussets to form triangular portions;
[0075] FIG. 6 is a perspective view of the FIG. 4 embodiment illustrating the inward folding of the triangular portions of the FIG. 5 embodiment;
[0076] FIG. 7 is a perspective view of the FIG. 4 embodiment illustrating a bag bottom formed from lower portions of the front and rear bag walls secured to each other and the ends of the side gussets;
[0077] FIG. 8 is a perspective view of the FIG. 4 embodiment illustrating the folding of the bag bottom along side the bag walls;
[0078] FIG. 9 is a perspective view of a stack of bags of the FIG. 4 embodiment;
[0079] FIG. 10 is a front elevational view of a third embodiment illustrating a header attached at a perforation line;
[0080] FIG. 11 is a front elevational view of a fourth embodiment illustrating a header having weakened areas in the hanging openings;
[0081] FIG. 12 is a front elevational view of a fifth embodiment illustrating a header attached at a perforation line, having a center tab and cold stakings or hot pinnings registering the bag pack;
[0082] FIG. 13 is a perspective view of the FIG. 10 embodiment illustrating the bag pack on a dispensing rack and glue spots adhering the bags together;
[0083] FIG. 14 is a perspective view of the FIG. 4 embodiment illustrating a bag with central handles;
[0084] FIG. 15 is a perspective view of the FIG. 4 embodiment illustrating a bag with microperforations in the front and rear bag walls and the gussets;
[0085] FIG. 16 is a front elevational view of a t-shirt style square bottom bag with center tab;
[0086] FIG. 17 is a front elevational view of a second embodiment of a t-shirt style square bottom bag having a central glue spot;
[0087] FIG. 18 is a front elevational view of a third embodiment of a t-shirt style square bottom bag having a center tab with a weakened area between the tab opening and the upper edge of the bag mouth;
[0088] FIG. 19 is a front elevational view of a fourth embodiment of a t-shirt style square bottom bag having a removable center tab joined to the bag with a frangible area;
[0089] FIG. 20 is a front elevational view of a fifth embodiment of a t-shirt style square bottom bag having a removable header joined to the upper edges of the bag handles with a perforation line;
[0090] FIG. 21 is a front elevational view of a sixth embodiment of a t-shirt style square bottom bag having a header joined to the upper edges of the bag handles and having weakened areas in the bag support openings;
[0091] FIG. 22 is a perspective view of an apparatus for forming the bags of the FIG. 4 embodiment including gusseting and slitting the extruded tubing;
[0092] FIG. 23 is a perspective view of the method of folding the lower ends of the bag gussets outwardly to form triangular portions;
[0093] FIG. 24 is a perspective view of the method of folding the triangular portions inwardly as part of the bag bottom;
[0094] FIG. 25 a perspective view of the method of folding the front and rear bag walls over the triangular portions and fastening them to each other, the triangular portions and the side gussets to form the bag bottom;
[0095] FIG. 26 is a bottom side view of the assembled bag illustrating the bottom and side seams;
[0096] FIG. 27 is a perspective view of the method of forming the FIG. 11 embodiment of a headered bag with attaching glue spots;
[0097] FIG. 28 is a perspective view of a method of adding vent holes to the bag walls as in the FIG. 15 embodiment;
[0098] FIG. 29 is a perspective view of a method of adding handleholes to the bag walls as in the FIG. 14 embodiment;
[0099] FIG. 30 is a perspective view of a method of using a hot pin to the bag walls to one another as in the FIG. 12 embodiment;
[0100] FIG. 31 is a perspective view of a method of forming a gusseted t-shirt style bag as in the FIG. 21 embodiment;
[0101] FIG. 32 is a perspective view of a method of forming a headered t-shirt style bag as as in the FIG. 20 embodiment;
[0102] FIG. 33 is a perspective view of a bag stack of square bottom t-shirt style bags being adhered together with a hot pin through an upper portion of the bags; and
[0103] FIG. 34 is a perspective view of a bag stack of square bottom t-shirt style bags being adhered together with a hot pin through the handles of the bags.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0104] (1) FIG. 9 illustrates a square bottomed plastic bag stack 10 providing the desired features that may be constructed from the following components. A plurality of stacked polyethylene film bags 15 is provided. As illustrated in FIGS. 1-3 , each of the bags 15 includes front 20 and rear 25 polyethylene film walls. Each of the front 20 and rear 25 walls have first 30 and second 35 side edges, a top edge 40 and a bottom edge 45 . Each of the bags 15 has a pair of longitudinally oriented side gussets 50 attached to the first 30 and second 35 side edges. Each of the bags 15 has a flat, rectangular bottom 55 formed of lower portions 60 of the front 20 and rear 25 walls and lower portions 65 of the side gussets 50 . As illustrated in FIGS. 8 and 9 , each of the bags 15 is folded inwardly at the side gussets 50 and upwardly from either the front wall 20 or the rear wall 25 at a point 70 spaced upwardly from the bottom edge 45 , to form a flattened bag 15 . The bags 15 are stacked upon one another and held in registration by attachment of the bags 15 to one another, thereby forming a registered bag stack 10 . As illustrated in FIGS. 10-12 , each of the bags 15 is attached at the top edges 40 of at least one of the front 20 and rear 25 walls to at least one header strip 75 . When the bags 15 are pulled from the bag stack 10 and opened, they will stand erect upon the flat bottom 55 .
[0105] (2) In a variant of the invention, as illustrated in FIGS. 4-7 , a plurality of stacked polyethylene film bags 15 is provided. Each of the bags 15 includes front 20 and rear 25 polyethylene film walls. Each of the front 20 and rear 25 walls has first 30 and second 35 side edges, a top edge 40 and a bottom edge 45 . Each of the bags 15 has a pair of longitudinally oriented side gussets 50 attached to the first 30 and second 35 side edges. Each of the bags 15 has a flat, rectangular bottom 55 formed of lower portions 60 of the front 20 and rear 25 walls and lower portions 65 of the side gussets 50 . As illustrated in FIG. 5 , lower corners 80 of the each side gusset 50 are folded outwardly and together to form downward pointing triangular panels 85 . As illustrated in FIG. 6 , the triangular panels 85 are folded inwardly from the side gussets 50 . Lower portions 60 of the front 20 and rear 25 walls are folded inwardly and sealed together to form the bag bottom 55 . As illustrated in FIGS. 8 and 9 , the bag bottom 55 is sealed to the side gussets 50 adjacent upper edges 90 of the triangular panels 85 . The triangular panels 85 are sealed to an upper surface 95 of the bag bottom 55 . Each of the bags 15 is folded inwardly at the side gussets 50 and upwardly from either the front wall 20 or the rear wall 25 at a point 70 spaced upwardly from the bottom edge 45 , to form a flattened bag 15 . The bags 15 are stacked upon one another and held in registration by attachment of the bags 15 to one another, thereby forming a registered bag stack 10 . When the bags 15 are pulled from the bag stack 10 and opened, they will stand erect upon the flat bottom 55 .
[0106] (3) In a further variant, as illustrated in FIGS. 4-7 , a plurality of stacked polyethylene film bags 15 is provided. Each of the bags 15 includes front 20 and rear 25 polyethylene film walls. Each of the front 20 and rear 25 walls has first 30 and second 35 side edges, a top edge 40 and a bottom edge 45 . Each of the bags 15 has a pair of longitudinally oriented side gussets 50 attached to the first 30 and second 35 side edges. Each of the bags 15 has a crease line 100 . The crease line 100 is parallel to the bottom edges 45 and spaced upwardly from the bottom edges 45 by approximately one half of a width 105 of one of the side gussets 50 . Each of the bags 15 is slit from the bottom edges 45 of the walls 20 , 25 to the crease line 100 at each intersection of the front 20 and rear 25 walls and the side gussets 50 .
[0107] Each of the bags 15 has a flat, rectangular bottom 55 formed of portions of the front 20 and rear 25 walls and portions of the side gussets 50 . Lower corners 80 of the each side gusset 50 are folded outwardly to the crease line 100 and together to form downward pointing triangular panels 85 . The triangular panels 85 are folded inwardly from the side gussets 50 at the crease line 100 . Lower portions 60 of the front 20 and rear 25 walls are folded inwardly from the crease line 100 and sealed together to form the bag bottom 55 . The bag bottom 55 is sealed to the side gussets 50 adjacent the crease line 100 and upper edges 90 of the triangular panels 85 . The triangular panels 85 are sealed to an upper surface 95 of the bag bottom 55 . Each of the bags 15 is folded inwardly at the side gussets 50 and upwardly from either of the front wall 20 and the rear wall 25 at the crease line 100 , to form a flattened bag 15 . The bags 15 are stacked upon one another and held in registration by attachment of the bags 15 to one another, thereby forming a registered bag stack 10 . When the bags 15 are pulled from the bag stack 10 and opened, they will stand erect upon the flat bottom 55 .
[0108] (4) In still a further variant, as illustrated in FIGS. 10-12 , each of the bags 15 is attached at the top edges 40 of at least one of the front 20 and rear 25 walls to at least one header strip 75 .
[0109] (5)
[0110] (6) In yet a further variant of the invention, as illustrated in FIGS. 10 and 12 , the header strip 75 is attached at the top edges 40 of at least one of the front 20 and rear 25 walls by at least one perforation 115 .
[0111] (7)
[0112] (8) In still another variant, as illustrated in FIGS. 10-13 , the header strip 75 has at least one hole 120 for suspending the bags 15 from a dispensing rack 125 .
[0113] (9)
[0114] (10) In yet another variant, as illustrated in FIG. 11 , the header strip 75 includes at least one weakened area 130 . The weakened area 130 extends from the hole 120 to an upper edge 135 of the header strip 75 .
[0115] (11) In a further variant of the invention, as illustrated in FIG. 13 , the square bottomed plastic bag stack 10 includes means 140 for attaching an upper portion 145 of the rear wall 25 of a leading one of the bags 15 to an upper portion 145 of the front wall 20 of a subsequent bag 15 in the bag stack 10 . When the leading bag 15 is pulled from the bag stack 10 , the subsequent bag 15 will cause the leading bag 15 to open.
[0116] (12) In still a further variant, as illustrated in FIG. 27 , the means 140 for attaching an upper portion 145 of the rear wall 25 of a leading one of the bags 15 to an upper portion 145 of the front wall 20 of a subsequent bag 15 in the bag stack 10 is selected from the group that includes glue spotting 150 , corona treatment 155 , pressure 160 and corona treatment with pressure.
[0117] (13)
[0118] (14) In another variant, as illustrated in FIG. 12 , the header strips 75 are attached to one another with at least one hot pin 165 extending through the headers 75 to maintain the bags 15 in registration.
[0119] (15)
[0120] (16) In still another variant of the invention, as illustrated in FIG. 12 , the header strips 75 are attached to one another with at least one cold stake 170 extending through the headers 75 to maintain the bags 15 in registration.
[0121] (17)
[0122] (18) In yet another variant, as illustrated in FIG. 14 , at least one handle opening 175 is provided. The handle opening 175 extends through the front 20 and rear 25 walls in an upper portion 145 of each of the bags 15 .
[0123] (19) In a further variant, the bags 15 are formed of a porous material (not shown).
[0124] (20) In still a further variant, as illustrated in FIG. 15 , the bags 15 are formed of material having microperforations 185 penetrating at least a portion 190 of any of the bag walls 20 , 25 and side gussets 50 .
[0125] (21) In another variant, as illustrated in FIG. 15 , the bags 15 have a plurality of ventilating openings 195 penetrating at least a portion 190 of any of the bag walls 20 , 25 and side gussets 50 .
[0126] (22) In still another variant, as illustrated in FIG. 16 , an upper seal 200 is provided.
[0127] The upper seal 200 joins the front wall 20 to the rear wall 25 at the top edges 40 of the bag walls 20 , 25 and joins top edges 205 of the side gussets 50 . A U-shaped cutout 210 is provided. The cutout 205 commences at a first point 215 on the upper seal 200 . The first point 215 is spaced from the first side edge 30 and extends downwardly toward the bottom edges 45 , across an upper portion 145 of the bag walls 20 , 25 and upwardly to a second point 220 on the upper seal 200 . The second point 220 is spaced from the second side edge 35 , thereby forming an open bag mouth 225 and a pair of bag handles 230 terminating at the upper seal 200 .
[0128] (23) In yet another variant, as illustrated in FIG. 16 , the bags 15 are attached to one another with at least one hot pin 165 extending through the bag handles 230 to maintain the bags 15 in registration.
[0129] (24) In yet a further variant, as illustrated in FIG. 17 , the bags 15 are attached to one another with at least one hot pin 165 extending through the upper portion 145 of the bag walls 20 , 25 to maintain the bags 15 in registration.
[0130] (25) In still a further variant, as illustrated in FIG. 16 , the bags 15 are attached to one another with at least one cold stake 170 extending through the bag handles 230 to maintain the bags 15 in registration.
[0131] (26) In another variant of the invention, as illustrated in FIG. 17 , the bags 15 are attached to one another with at least one cold stake 170 extending through the upper portion 145 of the bag walls 20 , 25 to maintain the bags 15 in registration.
[0132] (27) In yet another variant, as illustrated in FIG. 17 , the bags 15 further comprise a pair of apertures 235 , each of the apertures 235 penetrating the bag handles 230 at a point 440 spaced downwardly from the upper seal 200 , the apertures 235 permitting the bag stack 10 to be suspended from a dispensing rack 125 .
[0133] (28) In still another variant, as illustrated in FIG. 19 , a central tab 240 is provided. The central tab 240 extends upwardly from at least one of the front wall 20 and the rear wall 25 at the open mouth 225 . The central tab 240 has an opening 245 through it for suspending the bag stack 10 .
[0134] (29) In a further variant, as illustrated in FIG. 19 , the central tab 240 is attached to at least one of the front wall 20 and the rear wall 25 at the open mouth 225 at a weakened area 250 . The weakened area 250 permits the central tab 240 to be torn from the open mouth 225 of the bag 15 as the bag 15 is removed from a dispensing rack 125 .
[0135] (30) In still a further variant, as illustrated in FIG. 18 , the central tab 240 includes a weakened area 250 . The weakened area 250 extends from the opening 245 to an upper edge 255 of the central tab 240 . The weakened area 250 parts under pressure as the bag 15 is removed from a dispensing rack 125 .
[0136] (31) In yet a further variant of the invention, as illustrated in FIGS. 20 and 21 , at least one header strip 75 is provided. The header strip 75 is attached above the upper seal 200 .
[0137] (32) In still another variant, as illustrated in FIG. 20 , the header strip 75 is attached above the upper seal 200 with at least one perforation 115 .
[0138] (33) In still a further variant, as illustrated in FIGS. 20 and 21 , the header strip 75 has at least one hole 120 therethrough for suspending the bag stack 10 .
[0139] (34) In a further variant, as illustrated in FIG. 21 , the header strip 75 includes a weakened area 130 . The weakened area 130 extending from the hole 120 to an upper edge 135 of the header strip 75 . The weakened area 130 parting as the bag 115 is removed from a dispensing rack 125 .
[0140] (35) In another variant, as illustrated in FIGS. 22-26 , a method of making a square bottomed plastic bag stack 10 , includes the following steps. Extruding a tube of polyethylene material 260 . Forming side gussets 50 in the tube 260 and flattening the tube 260 . Cutting the flattened tube 260 perpendicular to the side gussets 50 to a first predetermined length 265 , thereby forming a bag blank 270 . The bag blank 270 has front 20 and rear 25 walls, front and rear top edges 40 , front and rear bottom edges 45 , first 30 and second 35 side edges. Slitting the bag blank 270 at intersections 320 of the side gussets 50 and the front 20 and rear 25 walls from the front 45 and rear 45 bottom edges upwardly for a first predetermined distance 325 . Folding lower corners 80 of the each side gusset 50 outwardly and together to form downward pointing triangular panels 85 . Folding the triangular panels 85 inwardly from the side gussets 50 . Folding lower portions 60 of the front 20 and rear 25 walls inwardly, as illustrated in FIG. 8 . Sealing the front 20 and rear 25 wall together adjacent the front and rear bottom edges 45 to form a bag bottom 55 . Sealing the bag bottom 55 to the side gussets 50 adjacent upper edges 90 of the triangular panels 85 . Sealing the triangular panels 85 to an upper surface 95 of the bag bottom 55 . Folding each of the bags 15 inwardly at the side gussets 50 and upwardly from either of the front wall 20 and the rear wall 25 at a point 70 spaced upwardly from the bottom edge, 45 to form a flattened bag 15 . Stacking a plurality of the bags 15 in registration to form a bag stack 10 as illustrated in FIG. 9 .
[0141] (36) In yet another variant of the method of making a square bottomed plastic bag stack 10 , includes the following steps, as illustrated in FIGS. 22 and 26 . Extruding a tube of polyethylene material 260 . Forming side gussets 50 in the tube 260 and flattening the tube 260 . Cutting the flattened tube 260 perpendicular to the side gussets 50 to a first predetermined length 265 , thereby forming a bag blank 270 . The bag blank 270 has front 20 and rear 25 walls, front and rear top edges 40 , front and rear bottom edges 45 , first 30 and second 35 side edges. Forming a crease line 100 in each of the bag blanks 270 . The crease line 100 is parallel to the bottom edges 45 and spaced upwardly from the bottom edges 45 by approximately one half of a width 105 of one of the side gussets 50 . Slitting each of the bag blanks 270 from the bottom edges 45 of the walls 20 , 25 to the crease line 100 at each intersection 320 of the front 20 and rear 25 walls and the side gussets 50 . Folding lower corners of the each side gusset 50 outwardly to the crease line 100 and together to form downward pointing triangular panels 85 . Folding the triangular panels 85 inwardly from the side gussets 50 at the crease line 100 . Folding lower portions 60 of the front 20 and rear 25 walls inwardly from the crease line 100 . Sealing the front 20 and rear 25 wall together adjacent the front and rear bottom edges 45 to form a bag bottom 55 . Sealing the bag bottom 55 to the side gussets 50 adjacent the crease line 100 and upper edges 90 of the triangular panels 85 . Sealing the triangular panels 85 to an upper surface 95 of the bag bottom 55 . Folding each of the bag blanks 270 inwardly at the side gussets 50 and upwardly from either of the front wall 20 and the rear wall 25 at the crease line 100 , to form a flattened bag 15 , as illustrated in FIG. 8 . Stacking a plurality of the bags 15 in registration to form a bag stack 10 , as illustrated in FIG. 9 .
[0142] (37) A further variant of the method of making a square bottomed plastic bag stack 10 includes the following steps, as illustrated in FIG. 27 . Prior to stacking the bag blanks 270 , perforating the bag blank 270 at a perforation line 365 , the perforation line 365 located at a second predetermined distance 370 from the front and rear top edges 40 . Cutting the bag stack 10 above the perforation line 365 to form a plurality of bag stack header strips 75 . Attaching the header strips 75 to one another to maintain the bags 15 in registration, as illustrated in FIGS. 30 . When the bags 15 are pulled from the bag stack 10 and opened, they will stand erect upon the flat bottom 55 .
[0143] (38) A still further variant of the method of making a square bottomed plastic bag stack 10 includes the following step of cutting at least one hole 120 in the header strips 110 for suspending the bags 15 from a dispensing rack 125 , as illustrated in FIG. 27 .
[0144] (39) Yet a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming at least one weakened area 130 . The weakened area 130 extends from the hole 120 to an upper edge 135 of the header strip 75 , as illustrated in FIG. 27 .
[0145] (40) Still a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of attaching an upper portion 145 of the rear wall 25 of a leading one of the bags 15 to an upper portion 145 of the front wall 20 of a subsequent bag 15 in the bag stack 10 . When the leading bag 15 is pulled from the bag stack 10 , the subsequent bag 15 will cause the leading bag 15 to open, as illustrated in FIG. 27 .
[0146] (41) Another variant of the method of making a square bottomed plastic bag stack 10 includes the step of providing a means for attaching an upper portion 145 of the rear wall 25 of a leading one of the bags 15 to an upper portion 145 of the front wall 20 of a subsequent bag 15 in the bag stack 10 . The means are selected from the following group that includes glue spotting 140 , corona treatment 155 , pressure 160 and corona treatment with pressure, as illustrated in FIG. 27 .
[0147] (42) Still another variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one hot pin 165 through the headers 110 to maintain the bags 15 in registration, as illustrated in FIG. 30 .
[0148] (43) Yet another variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one cold stake 170 through the headers 110 to maintain the bags 15 in registration, as illustrated in FIGS. 12 and 17 .
[0149] (44) A further variant of the method of making a square bottomed plastic bag stack 10 includes the step of cutting at least one handle opening 175 in the bag blank 270 . The handle opening 175 extends through the front 20 and rear 25 walls in an upper portion 145 of each of the bags 15 , as illustrated in FIG. 29 .
[0150] (45) Still a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming the bags 15 of a porous material (not shown).
[0151] (46) Yet a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming microperforations 185 penetrating at least a portion of any of the bag walls 20 , 25 and side gussets 50 , as illustrated in FIG. 15 .
[0152] (47) Still a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming a plurality of ventilating openings 195 penetrating at least a portion of any of the bag walls 20 , 25 and side gussets 50 , as illustrated in FIG. 15 .
[0153] (48) Another variant of the method of making a square bottomed plastic bag stack 10 includes the following steps. Prior to stacking the bag blanks 270 , joining the front wall 20 to the rear wall 25 at the top edges 40 of the bag walls 20 , 25 and joining top edges 40 of the side gussets 50 , thereby forming an upper seal 200 . Forming a U-shaped cutout 210 . The cutout 210 commences at a first point 215 on the upper seal 200 spaced from the first side edge 30 and extends downwardly toward the bottom edges 45 , across an upper portion 145 of the bag walls 20 , 25 and upward to a second point 220 on the upper seal 200 spaced from the second side edge 35 , thereby forming an open bag mouth 225 and a pair of bag handles 230 terminating at the upper seal 200 , as illustrated in FIG. 31 .
[0154] (49) Still another variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one hot pin 165 through the upper portion 145 of the bag walls 20 , 25 to maintain the bags 15 in registration, as illustrated in FIG. 33 .
[0155] (50) A further variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one hot pin 165 through the bag handles 230 to maintain the bags 15 in registration, as illustrated in FIG. 34 .
[0156] (51) Yet a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one cold stake (not shown) through the upper portion of the bag walls 20 , 25 to maintain the bags 15 in registration.
[0157] (52) Still a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of driving at least one cold stake (not shown) through the bag handles 230 to maintain the bags 15 in registration.
[0158] (53) Another variant of the method of making a square bottomed plastic bag stack 10 includes the step of cutting a pair of apertures 235 , as illustrated in FIG. 31 . Each of the apertures 235 penetrates the bag handles 230 at a point 440 spaced downwardly from the upper seal 200 . The apertures permit the bag stack 10 to be suspended from a dispensing rack 125 .
[0159] (54) Still another variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming a central tab 240 , as illustrated in FIG. 31 . The central tab 240 extends upwardly from at least one of the front wall 20 and the rear wall 25 at the open mouth 225 . The central tab 240 has an opening 245 through it for suspending the bag stack 10 .
[0160] (55) Yet another variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming a weakened area 250 , as illustrated in FIG. 31 . The weakened area 250 attaches the central tab 240 to at least one of the front wall 20 and the rear wall 25 at the open mouth 225 . The weakened area 250 permits the central tab 240 to be torn from the open mouth 225 of the bag 15 as the bag 15 is removed from a dispensing rack 125 .
[0161] (56) A further variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming the central tab 240 with a weakened area 250 , as illustrated in FIG. 18 . The weakened area 250 extends from the opening 245 to an upper edge 255 of the central tab 240 . The weakened area 250 parts under pressure as the bag 15 is removed from a dispensing rack 125 .
[0162] (57) Still a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of attaching a header strip 75 above the upper seal 200 , as illustrated in FIG. 32 .
[0163] (58) Yet a further variant of the method of making a square bottomed plastic bag stack 10 includes the step of attaching the header strip 75 above the upper seal 200 with at least one perforation 115 , as illustrated in FIG. 32 .
[0164] (59) Another variant of the method of making a square bottomed plastic bag stack 10 includes the step of cutting at least one hole 120 through the header strip 75 for suspending the bag stack 10 , as illustrated in FIG. 32 .
[0165] (60) A final variant of the method of making a square bottomed plastic bag stack 10 includes the step of forming a weakened area 130 , as illustrated in FIG. 11 . The weakened area 130 extends from the opening 410 to an upper edge 135 of the header strip 110 . The weakened area 130 parts as the bag 15 is removed from a dispensing rack 125 .
[0166] An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and the detailed description of a preferred embodiment.
|
A square bottom plastic bag is designed to stand upright when opened. The bags are constructed with open tops, side handle openings and attached headers or with t-shirt style handles. The bags are produced in registered bag stacks and include means for adhering a rear surface of one bag to a front surface of a subsequent bag to make the bags self-opening when used with a dispensing rack. The headered bags have tear-off headers or headers with weakened areas that will rupture upon dispensing. The t-shirt bags have apertures through the handles to suspend the bags on a rack or a header attached above the handles. The bags have detachable or rupturable center tabs. The bags are registered with hot pins or cold stakes through an upper portion of the bags or bag handles. The bags have openings, microperforations, or are formed of porous material to dissipate heat or moisture.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is related to co-pending U.S. patent application Ser. No. 11/854,448 titled “Networked Gaming System with Player-Centric Rewards” filed Sep. 12, 2007 and U.S. patent application Ser. No. 11/854,424 titled “Gaming Machine With Player-Centric Rewards” filed Sep. 12, 2007.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the invention relates to wagering games processes, and more specifically to methods for providing player-centric gaming rewards.
2. Description of the Related Art
Modern gaming establishments offer a variety of electronic wagering games including multimedia and/or mechanical slot machines providing video card games, such as poker, blackjack and the like, video keno, video bingo, video pachinko, and various other video or reel-based games. In addition, casinos offer a variety of table games, such as poker, blackjack, craps, roulette, and the like. In many instances, the slot machines and table games are computerized or include electronic circuitry performing various functions, and are connected via a networked gaming environment to a host computer and associated servers.
Software programs provide gaming establishments with the ability to compile information about casino players, to monitor the status of games, and to provide promotions, bonuses, and rewards. Examples of promotions include advertisements and rewards, which serve as incentives for casino players to continue wagering and to return to the same establishment.
For example, one gaming bonus or reward, called “Lucky Stars”, has been used since the 1989 timeframe at the Sands in Atlantic City, N.J. in conjunction with its slot management (SMS) and casino management (CMS) systems (today's Bally/ACSC SMS and CMS, respectively) and may be described as follows:
“Lucky Stars transactions” may be generated for patrons with their patron card inserted into a casino asset card reader such as are commonly found on slot machines. According to one implementation, from a user (host) interface of the SMS slot system, a casino may select the amount of monies (whole dollars) to be played at an asset, such as a slot machine, prior to awarding a Lucky Star. Once selected, the whole dollar amount is converted by the SMS according to the slot denomination of the asset into a number of clicks (coins to be played), and the number of clicks is downloaded to the gaming machine as the Lucky Star Limit. Once the Lucky Star Limit is set, a counter at the gaming machine will increment the Lucky Stars Count for each coin played while any patron card is inserted. After each increment, the current Lucky Stars Count is compared with the Lucky Stars Limit. The incrementing and accumulation continues as successive patrons utilize the gaming machine. Once the Lucky Stars Count matches the Lucky Star Limit, the slot machine generates a “Lucky Stars transaction” for transmittal to the CMS, resets the Lucky Stars Count back to zero, and re-initiates incrementing the Lucky Stars Count. When the “Lucky Stars transaction” message is received by the CMS, it may randomly or by design determine if the patron is to receive a sweepstakes entry or other award for earning a “Lucky Star”. Once a determination is made, the CMS causes a record to be generated and the patron that caused the “Lucky Stars transaction” to be generated is notified of the available award that has been assigned to the patron's account by a message, either transmitted to the gaming machine where the patron has his/her card inserted or the next time that the patron's card is utilized.
These types of rewards and others are popular, and, there continues to be a need to develop creative methods and systems to provide various types of rewards to patrons.
BRIEF SUMMARY OF THE INVENTION
In accordance with the invention/s, gaming methods are provided that offer one or more player-centric rewards to players, such as a sweepstakes entry, birthday reward, or gaming reward, triggered by an occurrence specific to the player, such as the player having a birthday or playing a pre-set amount at one or more games. In one aspect, a player-centric gaming reward and/or promotion offered to a player may be based on criteria such as a player rating and/or wagering denomination.
Other features and numerous advantages of the various embodiments will become apparent from the following detailed description when viewed in conjunction with the corresponding drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example flow diagram of an example sweepstakes award transaction in accordance with various embodiments.
FIG. 2 illustrates an example flow diagram of an example personalized award transaction in accordance with various embodiments.
FIG. 3A illustrates an example high-level block diagram of a gaming machine in accordance with various embodiments.
FIG. 3B illustrates an example gaming machine in accordance with various embodiments.
FIGS. 4A and 4B illustrates a simple block diagram of a rewards server connecting over a network to a representative example gaming machine in accordance with various embodiments.
FIG. 5 illustrates an example bonus rewards control process flow diagram in accordance with various embodiments.
FIG. 6 is an example bonus rewards control process flow diagram in accordance with various embodiments.
FIG. 7 is an example flowchart of a bonusing rewards process in accordance with various embodiments.
FIGS. 8 and 8A are example SMS block diagrams including transaction flow in accordance with various embodiments.
FIG. 9 is an example flow diagram of a player-centric rewards system in accordance with various embodiments.
FIG. 10-23 are example displays of a rewards program user menu in accordance with various embodiments.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like reference numbers denote like or corresponding elements throughout the drawings, and more particularly referring to FIG. 1 , a flow diagram illustrates an example award transaction process, such as may be utilized to provide player-centric rewards to eligible patrons based upon pre-selected criterion, in accordance with one or more embodiments. In the example shown in FIG. 1 , the award is a sweepstakes entry which may be an entry for a sweepstakes of the quick draw variety that allows an operator to instantly determine the prize won by the particular sweepstakes entry or the entry may be for a sweepstakes of the raffle variety where the selection of winning entries may be made at some time in the future. It may be appreciated that the award may be any type of award including a cash bonus, playing credit, gifts of merchandise, gifts of services, or a player-centric game, to name a few. The award which may be offered through the award transaction process may be one of various levels of rewards depending upon the outcome of the process and the patron may thereafter be offered the opportunity to select a prize from one of the prizes available at the offered award level. The offered prizes may be any such as identified above for the various types of rewards. As an example, a player-centric game with various awards may be offered based on the player level and have various tiering of the awards based on the player level. As an additional aspect, several player-centric games may be offered to a patron based on known preferences, such as may be stored in a database, or based on demographic information.
In the example sweepstakes award transaction process of FIG. 1 , a patron may be identified (step 105 ); a determination may be made whether an award is available (step 110 ); according to pre-specified player-specific criteria, a determination may be made whether the patron is eligible for an award (step 115 ); if the patron is eligible, then a determination may be made as to what award may be offered to the patron (step 120 ); a transmission of an award message may be sent to the patron (step 130 ); an award record associated with the patron may be created (step 135 ); and the patron may be provided with an opportunity to redeem the reward (step 140 ).
Patron identifying step 105 may, by example, be performed by passing an identification card by or into a card reader, such as an optical card reader, by visually identifying the patron, by proximity emitter and/or identity sensor, such as a biometric sensor, or any other direct or indirect method that reasonably identifies and/or associates a patron with a game, gaming apparatus, and/or gaming system. If used, an identification card or device may utilize barcoding or a data strip, such as a magnetic strip, for providing identification information. One or more sensors within an operator's facility may be used to receive the information to identify the patron. For instance, various gaming machines have a player interface which may permit a patron to insert a patron or player card into a card reader. An example of a patron interface unit that is found implemented with various gaming machines is the Bally iView interface unit, such as is described in U.S. patent application Ser. No. 10/943,777, entitled USER INTERFACE SYSTEM AND METHOD FOR A GAMING MACHINE, which is herein incorporated by reference. In one or more embodiments, a patron may enter a user identification and/or password to provide identification information at a gaming machine or within an operator's facility; in such instances, a patron may be able to obtain additional access to the patron's player account and be able to make transfers, such as transferring credits from the player account to a gaming machine for wagering or accepting an award that has been posted to the player account.
Once a patron has been identified, that person's player information may be retrieved from the operator's player database, then an operator may track the wagering and/or spending habits of the patron and utilize a variety of statistics to determine appropriate situations for offering various bonuses or rewards, such as sweepstakes entries, promotions, coupons, or rewards for playing or spending at the operator's facilities. The player information may contain personal information such as birthday, address, etc. and may also contain the patron's gaming and/or spending history within the operator's facilities and possibly at other facilities. The patron's gaming and/or spending history may simply summarize the patron's previous activities. Also, the player information may include a rating of the patron which may be developed from the patron's gaming and/or spending history in accordance with the operator's criterion; for example, an operator may rate patron's at a gold player level if historically the patron bets more than $10,000 and spends four hours or more, five or more times per month or if the patron spends more than $1000 on goods or services within the operator's facilities, five or more times per month. The operator may have various player/patron levels or ratings, such as gold, silver, and bronze, with various criterion to associate with each patron level or rating.
Award availability step 110 may, by example, be performed by simply checking to see if a game, gaming apparatus, and/or gaming system is currently set, programmed, or otherwise enabled to provide rewards to eligible patrons, such as patrons who have identified themselves by inserting their player cards into player tracking units associated with respective slot machines. For example, when a patron inserts a player card into a player card reader attached to a slot machine, a program on the gaming machine may be installed and become active upon the player card insertion. The card reader transmits the player information to a processor which may in turn be a signal to execute a program or protocol. As the program is executed by the processor, steps in the program may include querying a player database to request the player information associated with the identification obtained from the player card. Upon receipt of the player information or selected portions thereof, such as player level or rating, the program may include conditional portions of code which may operate depending upon the player level or rating. For instance, in the event that the player level or rating is gold, then a count limit may be set to a number of credits corresponding to $100 of wagers, the count limit could be decremented according to the number of credits wagered until the count limit reaches zero or alternatively a counter could be used to accumulate the total number of credits wagered until the count in the counter matched the count limit. The described steps of the program may be implemented on a slot machine or other gaming machine or device operated by a patron or the program may be implemented on or through other devices, such as a player tracking server. In either case, the program may be installed and active or not active depending upon the choice of the operator and the award availability step 110 may take place as background processing having no impact on a game being played by a patron until and unless the patron played sufficiently to meet any predetermined criteria associated with any active award program.
Alternatively, player-centric rewards may always be available subject to predetermined constraints which may be editable by the operator. In such cases, step 110 may be modified according to the particular implementations such as those discussed by example. For instance, award availability step 110 may include a determination of whether one or more pre-determined criteria have been met by the patron, thereby making the patron eligible to receive an award, such as cash, a sweepstake entry, and/or a sweepstake award. Example pre-determined criteria may be that the patron wager a pre-determined amount of money or wagered a pre-determined amount of money within a pre-determined amount of time or spent a pre-determined amount of money at a game, a gaming apparatus, a casino facility, and/or a gaming system. Other examples of pre-determined criteria may be that the patron enters a facility within a pre-determined number of days of their birthday, wedding anniversary, anniversary of establishing a player card, or other day associable with the patron. Other examples of pre-determined criteria may be that the player entered the facility and/or played a game during a pre-determined time of a pre-determined day, or may be that the player was drawn from a random or pseudo-random drawing either before or after entering the facility and/or playing a game, or may be any of various events associable with the patron. Any of the pre-determined criteria, such as the pre-determined amount of money to be wagered, may be determined by the operator of the game, gaming apparatus, and/or gaming system.
As shown in FIG. 1 , the award may be a conventional sweepstake entry. The sweepstake entry may be an entry which can be instantly included in a drawing, such as one based on a random or pseudo-random number generator, or may be an entry included in a pool for a later drawing, or may be an entry with a number that was randomly or pseudo-randomly determined and which may be compared as against a list of prize-winning numbers. In any of the example cases, there may be a variety of levels of prizes or there may be a single prize, such as a new car or large cash fund. Limitations may be placed on the sweepstake entry, such as that the patron may be required to be present at the time of the drawing in the case of a later drawing or the patron must come into the facility on the day of the drawing or redeem any winning sweepstake entry within a pre-determined period of time. Any of the limitations or pre-determined criteria may be modified by an operator according to player criteria, such as player rating or player playing frequency, etc. For example, player ratings for a facility may be platinum, gold and silver where the ratings may be determined from various criteria associable with a player, such as the amounts wagered, frequency, and type of game played. As an example, a platinum player may have three days to redeem a sweepstakes entry, and gold player may have two days, and a silver player may have to redeem the sweepstakes entry on the day an award is offered.
In one or more embodiments, in the event that the rewards functionality is activated and the patron is eligible for an award, patron eligibility step 115 may, by example, include a determination whether a player's rating meets a pre-specified rating level to receive an award, and/or, the determination may include whether the player may be eligible to receive a pre-determined level of award. In some cases, there may be more than one prize that may be available at an award level and a patron who is eligible may have an opportunity to select a prize from the one or more available prizes at a determined award level.
Depending on the outcome of the patron eligibility step 115 , steps for award and redemption opportunity (such as by example, steps 120 , 130 , 135 ) may be included. The steps for award and redemption may be as simple as an agent for the operator or an automated award system selecting an award and delivering the award to a patron for acceptance, either directly or by separate offer through a player account. In other embodiments, the patron may be entered into an instant or subsequent sweepstakes. In such cases, the patron may be provided with a record of the patron's entry into the sweepstakes or may be provided with or offered an award as the result of a winning entry.
Notification step 130 may be any form of messages including verbal or visual which may be perceived by the patron, e.g. an award notification message sent from a player server and displayed on the player tracking display or an award notification sent in the mail. In the case of a notification by mail, a patron may have a pre-specified period of time, such as thirty days, to return to an operator's facility to redeem the award.
Logging step 135 may comprise any method or system for recording information which the operator may use to maintain records of its rewards. For instance, an award database may be maintained by an award server which may comprise a conventional computer with a hard drive and an award program causing award records to be entered and stored when the program is executed by the computer.
Patron access step 140 may comprise any method or system providing a patron with an opportunity to receive and/or accept a reward offered to the patron by the operator. For example, a patron may be able to accept and receive an award by putting the patron's card into a player card reader at a gaming machine, entering the player card personal identification number (PIN) on a player interface such as a keypad, and making a request and/or responding to any prompt from a player tracking server.
One or more embodiments may include establishing a Count Limit which may be associated with a patron identified at a gaming machine. The Count Limit may be decremented after each play by the patron in accordance with the amount of the wager or number of credits wagered. The Count Limit may be a dollar amount, such as $100, $1000, $10000, etc. or may be an amount in terms of a non-U.S. currency. Alternatively, the Count Limit may be a number corresponding to credits required to be wagered prior to becoming eligible for an award. The Count Limit may be changed in terms of denominations wagered and associated with a credit. For instance, a Count Limit for a $1 slot machine may be one hundred; a corresponding Count Limit for a $0.25 slot machine may be four hundred, and so forth. A Count Limit may be associated with each patron and decremented according to the patron's play. Alternatively, multiple Count Limit's may be associated with a patron according to credit denominations, such as $1, $0.25, $0.05, etc. slot machines. For instance, each Count Limit may be 1000 and a Count Limit may be associated with penny, nickel, quarter, and dollar wagering such that when a patron wagers at a quarter slot machine the Count Limit associated with quarters is decremented. Additionally, an operator may select a weighted Count Limit to favor patron's at higher denomination slot machines. For example, an operator may establish a Count Limit of 100 for $1 slot machines, a Count Limit of 600 for $0.25 slot machines, and so forth. In the event that an award system includes a feature for a patron to have a Count Limit carry from slot machine to slot machine, then the Count Limit may adjust to the lowest denomination wager that the patron plays in order to become eligible for an award. For example, a patron may begin playing on a $1 slot machine and a Count Limit for the player may be set at 100. The patron may play 50 credits and then move to a $0.25 slot machine. If the award system is set for a patron to have a single Count Limit as opposed to a denomination specific Count Limit and also includes the capability to carry a count to another slot machine, then the count may have a one to one credit adjustment so that the Count Limit may be adjusted to two hundred or if there is a fifty percent higher Count Limit for $0.25 denomination wagering, the Count Limit may be adjusted to three hundred. Thus, when a patron plays at a different denomination game, then the Count Limit associated with that denomination is decremented with each credit wagered.
The current Count Limit for a patron may be displayed for a patron so that the patron may view as the Count Limit decrements towards zero. When the Count Limit reaches zero, then an award may be initiated for the patron if the patron meets any additional pre-determined criteria, such as patron player rating. Alternatively, the player rating may determine the type of award or value of the award to be offered to the patron. In the event that a patron does not have a sufficient player rating to participate in the player-centric award program, then no Count Limit is set and none is displayed. Additionally, as a patron plays, the patron may establish an eligible player rating and a Count Limit may thereafter be set and displayed for the patron.
One or more embodiments may include a Count Limit and a Count wherein the Count is incremented with each wager and the Count is compared with the Count Limit. As the Count, or Count Limit as discussed in the preceding paragraph, is personal to the patron when a patron leaves a game, the Count or Count Limit state does not carry over to a next player. Instead, the Count or Count Limit state may or may not carry over for a given patron for another gaming session or on a different gaming machine depending upon the settings established by the operator. In one or more embodiments, the Count, or Count Limit if decremented based on wager, may be retained and associated with a patron so that when the patron returns to play a game, which may be the same or a different game, the Count or Count Limit can continue from where it was at the time the patron ceased previous play. In such cases, the state may be maintained for a pre-determined period of time and then be reset. Also, the pre-determined period may be the same or different depending upon player rating or other player-centric criteria. For example, a gold level player may have the player-centric award game state maintained for three days, while a silver level player may have the game state maintained for two days, or a bronze level player may have the game state maintained only for a few hours. In another embodiment, there is no carry over of the Count or Count Limit which may be used to induce a patron to continue play. A visual or sound aid may apprise the patron of the current status of the Count or Count Limit and provide encouragement to continue until the patron may become eligible for an award. Also, the order of the steps as indicated in the above examples, may be shifted such that an operator may determined that a patron is eligible for an award once the Count or Count Limit criteria is met and the patron may be notified periodically or occasionally, accordingly.
In one or more embodiments, the Count or Count Limit may be applied to a group. For instance, a Count or Count Limit may be displayed to a group of players. As each player wagers, a communal Count or Count Limit is adjusted until a wager causes the final decrement or increment of the Count or Count Limit to achieve the final pre-determined value or decrement to zero. The patron that causes that value to be achieved will be eligible to receive the reward if there are no other criteria to be met. Rewards may be tiered so that the first eligible patron to achieve a pre-determined value may be eligible to receive one level of reward, and the next eligible patron to achieve a second pre-determined value may be eligible to receive a second level of reward, and so forth. Alternatively, consolation or lower tiered (valued) rewards may be offered to those players whose individual Count matches the Count Limit after the first player has done so. Thus, patrons may be incentivized in a competitive environment to play for the next reward level.
Similarly, in one or more embodiments, such a tiered reward system may be implemented for a single patron, so that once a patron achieves one level of Count, such as 1000, then the patron may be eligible for one level of award, such as a selection of stuffed toys or $25 playing credit. By deferring the lower award and continuing to play, the patron may play towards a second level of Count, such as 2500, which once achieved may allow a patron to be eligible for a second level of award, such as a night's stay or a dinner or $50 playing credit. The patron's Count may be incremented either in a single session or over multiple sessions and multiple games.
In one or more embodiments, the Count or Count Limit may be displayed either intermittently or continuously. In an intermittent example, when the patron's credits reach a pre-determined amount or after a pre-determined amount of play or when the patron requests the patron's player card or when the patron requests a cash out, a display or announcement may apprise the patron that the patron may be eligible for an award after another x number of plays. The visual, audible, or written report may indicate that play must be continued within a pre-determined amount of time, such as one hour, one day, one week, one month, etc. in order for the patron to retain the current count. If play is not recommenced within the pre-determined timeframe by the patron then the Count or Count Limit may be reset to the default initial value.
In one or more embodiments, player points may be accrued or bonuses won or granted in addition to the rewards as described herein. For example in parallel and independent of the rewards processes and systems described herein, player points may accrue conventionally through accumulations based on amounts of play and various bonuses awarded included mystery bonuses which may be triggered randomly, pseudo-randomly, or upon an event unknown to the patron, bonuses triggered by an event such as a jackpot win, and progressive bonuses, all or any of which may be funded from portions of coin-in or funded by the operator such as with marketing or advertising dollars.
In one or more embodiments, the player-centric rewards as described in the processes and systems herein may be funded as a portion of coin-in or by operator self-funding such as marketing dollars or by advertisers' prize contributions which are provided in return for advertising exposure, such as a Pioneer Widescreen TV or a Mercedes Benz automobile.
In one or more embodiments, a patron may receive an award directly or indirectly. For example, a patron may receive an award directly in the form of cash or a non-cash prize given at the game. Alternatively, a patron may receive an award indirectly by crediting the player's account as in the example of a cash prize or providing a patron with a notice for redemption in the case of a non-cash prize. A notice for redemption (or advisement that an award has been granted and may be redeemed, etc.) may be displayed to the patron while playing the game or after presenting the patron's player card to a machine or person after the notice has been associated with the patron's player card, etc.
In one or more embodiments, a patron may be given an opportunity to select from a range of prizes for which the patron is eligible. The patron may be notified visually or orally and may make a selection accordingly. The range of prizes may include cash, credit, services and/or tangible prizes.
In one or more embodiments, the referred to prior art award associated with a game, independent of a particular player, may have a Count and/or Count Limit associated with it and an award may be granted or offered to a patron in addition to and independent of the patron's personalized Count and/or Count Limit and rewards associated therewith. The game Count and/or Count Limit may be unknown or made known to a player. In the case of an unknown game Count and/or Count Limit, once a pre-determined amount of gameplay is met, then the award may be granted to an eligible patron such as a mystery award. The patrons may be generally aware of the rewards available but not specifically as to the game upon which the patron plays. In other embodiments, the patron may be notified of the game Count or Count Limit to incentivize the patron to continue playing.
In one or more embodiments, the patron and/or game Count or Count Limit may be pre-determined by the operator or may be randomly or pseudo-randomly established for one or more award categories. Additionally, prizes or their respective categories may be pre-determined by the operator or may be randomly or pseudo-randomly selected, as for example in the case of sweepstakes drawings. By introducing the random or pseudo-random element, larger prizes may be offered at more infrequent intervals as compared to lesser prizes, which may add another level of excitement and opportunity for the patrons.
In one or more embodiments, the prizes may be in the form of restricted or unrestricted credits. In either case, the credits may be credited to the patron's player account or directly to the game where the patron is playing. In the case of restricted credits, a patron may not directly exchange them for cash and may only use them for wagering on one or more games; whereas, unrestricted credits may be exchanged for cash.
Referring now to FIG. 2 , a flow diagram of a second player-centric rewards transaction process is shown according to one or more embodiments. In this example, the award is a birthday award. In other examples, instead of a birthday, any other day associable with the patron may be selected for offering an award to the patron. For instance, an award may be offered on an anniversary or a holiday, or any other day pre-selected by the operator that may be associated with the patron. The criteria may be based on demographic information or biographical information to provide eligibility for demographic-based or biographical-based rewards, such as for example, patrons from outside the U.S. may be eligible for a demographic-based reward or patrons who are firemen may be eligible for a biographical-based reward.
As in the example process shown in FIG. 1 and discussed above, the corresponding steps shown in FIG. 2 include: identifying the patron (step 205 ); determining if a type of player-centric award is available (step 210 ); according to pre-specified player-specific criteria, determining if the patron is eligible for the type of award (step 215 ) and if so determining and/or assigning the award to be offered to the patron (step 235 ); transmitting an award message to the patron (step 240 ); creating an award record associated with the patron (step 245 ); and providing the patron with an opportunity to redeem the award (step 250 ).
In the example shown in FIG. 2 where a type of award is active and the patron holds a card-level or rating sufficient for eligibility for the type of award, additional steps within the process include determining whether the current date falls within a pre-determined range of dates or days associated with the patron's birthday (step 220 ), and, determining whether the type of award has been previously received by the patron (step 230 ).
With respect to the range of dates in step 220 , an operator may select one or more days or time periods as eligible timeframes for a patron to appear at an operator's establishment and/or take part in an eligible activity, such as playing a game provided by the operator. The days or time periods selected by an operator may be symmetric or assymetric about the birthday. For instance, symmetric eligibility periods may be defined as: the day before through the day after for gold rated players; two days before through two days after for platinum rated players; and simply the day of the birthday for silver rated players. On the other hand, there may be no differentiation between player ratings.
With respect to determining whether an award has already been received by a patron in step 230 , an operator may establish that the birthday reward may only be offered and received once. In another embodiment, the operator may establish that a patron may receive a birthday award more than once. For example, the operator may select that a birthday award be awardable to eligible patrons during each day of the week of the patron's birthday or once per week during the patron's birth month.
In one or more embodiments, a patron may be eligible and awarded or offered an award for more than one event-driven award, such as a birthday award and an anniversary award or a birthday award and a holiday award, etc. Additionally, the patron may be eligible for and be awarded or offered a sweepstakes or other award based upon the patron's play.
Referring to FIGS. 3A and 3B , a block diagram and front view of example gaming machine 300 are shown, respectively. Gaming machine 300 may include apparatus and/or software for implementing one or more player-centric rewards processes as discussed above and in accordance with one or more embodiments. Typically, gaming machine 300 is implemented as an electronically functional device using conventional personal computer technology with few or no moving parts; however gaming machine 300 may also be implemented as an electro-mechanical or mechanical device.
For example, gaming machine 300 as shown in FIGS. 3A and 3B may include a game printed circuit board including game processor 110 , memory 115 which may store the game machine operating system and game presentation software 120 , network interface 125 for connecting to an operator's network, video display 130 which may display a game driven by processor 110 and may have fields for example displaying player credits, wager, win amount, etc., user input devices 135 which may provide buttons or video fields for a user to communicate with gaming machine 300 through processor 110 , user card interface 140 which may provide a device for transmitting player card information to processor 110 , and peripheral devices 145 such as a bill acceptor or ticket dispenser, etc.
In the example of a video gaming machine, game processor 110 communicatively connects to video display 130 which displays images of reels that function equivalently as mechanical or electro-mechanical reels, user interface unit including user input devices 135 which provides information to a patron and permits patron communications with the game processor and/or a network connected through network interface 125 , user card interface 140 which provides a device for receiving and reading player card information, and peripheral devices 145 , such as a bill reader for receiving and reading various bill denominations, coupons, and/or credit vouchers, and, a voucher printer which may be combined with the bill reader and may print credit vouchers when a patron wishes to cash out and/or print rewards vouchers when a patron accepts an award.
Video display 130 may be any of a variety of conventional displays, such as a high resolution LCD flat panel, and may have touch screen display functionality so that a patron can make software-enabled selections which may be associated with the game. Apart from its conventional functionality in presenting a game for a patron, gaming machine 300 may include award software which may be stored in memory 115 and hardware which may be part of or connected to the game board to implement one or more player-centric rewards processes as disclosed above by example. Video display 130 may include a separate user display such as an LCD touch screen display with interactive capability for communication between a user, gaming machine 300 , or a network connectable through network interface 125 .
Memory 120 may include both memory internal and external to processor 110 . External memory may include a hard drive, flash memory, random access memory (RAM), read only memory (ROM), and any other conventional memory associable with a printed circuit board.
In the event that gaming machine 300 is connected to a network, then the rewards software and hardware may be implemented wholly or partly externally and may be communicatively connected to the user interface unit for notifying patrons of rewards and receiving patron communications, such as award acceptances. For instance, gaming machine 300 may have a game management unit (GMU) which connects to a slot management (SMS) and/or casino management (CMS) network system. The GMU may in turn connect to the game board and the user interface unit. The player-centric rewards may be driven through the GMU, either directly or indirectly through the SMS and/or CMS which is discussed more fully below.
Referring to FIGS. 3A and 3B , typically, gaming machine 300 , such as Bally's S9000 Video Slot machine, comprises microprocessor 310 , such as an Intel Pentium-class microprocessor, and non-volatile memory 315 operable to store a gaming operating system, such as Bally's Alpha OS, and one or more gaming presentations 320 , such as Bally's Blazing 7's or Bonus Times for example, operable and connected on a printed circuit motherboard with conventional ports and connections for interfacing with various devices and controlling the operation of gaming machine 300 . Memory 315 may store one or more software modules operable with the OS to implement one or more reward processes, such as are shown in FIGS. 1 and 2 and described above.
Gaming machine 300 may optionally include network interface 325 operable to download one or more gaming presentations 320 from the one or more gaming servers (not shown) and to otherwise communicate with networked devices and servers for various purposes; however, one or more player-centric award processes as described above by example may be implemented with or without network support depending on implementations as is described further below. Gaming machine 300 may further comprise a video display 330 , through which gaming presentations are presented to the user; however, electro-mechanically driven reels may be implemented in place of or together with video display 330 . Gaming machine 300 may further comprise user interface devices 335 , such as a keyboard (not shown) which may be used to enter a pin number or for the selection of various options, various player selectable buttons 337 including bet one, bet all and the like, as well as a touch screen which may be incorporated with video display 330 or display 339 , such as an iView TFT display. Gaming machine 300 also includes user card interface 340 , which is operable to accept a user card that identifies a user as a casino patron to the gaming environment. Gaming machine 300 may further include one or more peripheral devices 345 , such as a bill/ticket acceptor, ticket printer, and various other devices. As shown in FIG. 3B , user card interface 340 and peripheral devices 345 , such as a bill acceptor may be implemented adjacent to each other or may be part of the same housing structure while connecting differently to perform their respective functions. In the event a network connection exists, then the user interface unit may provide a communication link for a patron with an SMS and/or CMS network.
In one or more embodiments, gaming machine 300 includes microprocessor 310 , which may implement the programming logic of the gaming presentations and control the operation of various hardware and software components of the gaming machine, as well as, one or more peripheral devices 345 . For example, microprocessor 310 may be operable to activate various components of the gaming machine 300 and, in the event of a network connection, to download one or more gaming presentations 320 from the gaming server. In response to a user input to initiate play and the placement of a wager, the microprocessor 310 may be configured to retrieve the requested gaming presentation 320 from memory 315 and to commence the play of the game. The microprocessor 310 may be configured to randomly select a game outcome from a plurality of possible outcomes and to cause the video display 330 to depict indicia representative of the selected game outcome. In the case of slots, for example, mechanical or simulated slot reels may be rotated and stopped to display symbols on the reels in visual association with one or more pay lines. If the selected outcome is one of the winning outcomes defined by a pay table, the microprocessor 310 may be configured to award the player with a number of credits associated with the winning outcome. Conventionally, in such gaming machines, a player may wager multiple credits on one or more lines depending upon the programming or physical limitations of the gaming machine.
In accordance with one or more embodiments, microprocessor 310 and/or related software and components may be configured to store a Count or Count Limit in accordance with the example rewards processes described above. For example, one or more registers from the microprocessor random access memory may be utilized to store a Count or Count Limit in accordance with one or more player-centric rewards processes which may be implemented with one or more rewards programs that may be stored in a permanent memory accessible to and compiled and/or executed by the game microprocessor in accordance with the inventions, such as have been discussed by example above and shown in FIGS. 1 and 2 .
For instance, in one or more example embodiments, a Count Limit, e.g. Count Limit equals one hundred (which may correspond to one hundred credits or $100 wagered depending upon programming and/or operator elections), may be uploaded to microprocessor 310 and/or related components associated with the game provided by gaming machine 300 , such as through a technician's input using the user interface or an alternative interface device, such as a wireless or wire-connected phone, tablet, or personal computer which may connect to gaming machine 300 through an infrared or similar wireless port or through a universal serial bus or similar wire-connected port connecting directly or indirectly to the game board. Where the game board may comprise a conventional personal computer board or one that may be modified for gaming purposes. The technician may be identified as authorized to input the Count Limit based on information obtained through a card reader from a technician's card and/or by the input of a password through user input devices 335 , such as a keypad or touch display.
In one or more embodiments, gaming machine 300 includes user input devices 335 , which may include various gaming controls, such as standard or game-specific push-buttons, a “bet” button for wagering, a “play” button for commencing play, a “collect” button for cashing out, a “help” button for viewing a help screen, a “pay table” button for viewing the pay table(s), a “call attendant” button for calling an attendant, and a “rewards button” for viewing player reward information and accepting various rewards, such as sweepstakes and birthday rewards. User input devices 335 may also include various game-specific buttons known to those skilled in the art. User input devices 335 may also include a keyboard, a pointing device, such as a mouse or a trackball, or any other input devices. In one or more embodiments, user input devices 335 may also comprise an embedded additional user interface (not depicted), such as an iView™ interface, as described in commonly owned U.S. patent application Ser. No. 10/943,771, entitled USER INTERFACE SYSTEM AND METHOD FOR A GAMING MACHINE, which is hereby incorporated in its entirety by reference herein. The content provided through the embedded additional user interface may include, for example, advertisements, promotion notifications, useful gaming information, user rewards information and any other content that may be of interest to the casino patron.
In one or more embodiments, the gaming machine 300 also includes user card interface 340 , which is operative to accept user cards containing the patron's identification information, such as the patron's ID number. User interface 340 may be configured to accept magnetic cards, smart (chip) cards, electronic keys and the like. It will be appreciated, however, that such user information may be stored in other forms or on other media for subsequent retrieval. For example, the user information can be stored on an RFID device, electronic key, or other portable memory device. Likewise, using biometrics or other techniques, user information may be retrieved from the game machine or from a remote storage device via a network. In an example embodiment, the system may recognize three different levels of user cards. For example, level one cards may identify frequent casino patrons, i.e., those who have a well-established history of playing at the given casino and/or whose wagering at the casino exceeds a specified threshold amount. Therefore, level one patrons will be entitled to the greatest degree of service, various promotions and rewards from the casino since they have met or exceeded a game threshold. The level two cards may identify patrons who frequent the casino, but whose spending at the casino is not as extensive as those of the level one card holders. Lastly, the level three cards may identify new casino patrons, i.e., those who do not yet have a consistent history of playing at the given casino. The degree of service, promotions and rewards offered to the level two and level three card holders likely will differ from that offered to the level one card holders, as will be described in a greater detail hereinbelow. The gaming system may be configured to recognize fewer or greater numbers of card levels, and that promotions and/or credits associated with each card level may differ.
In one or more embodiments, gaming machine 300 includes one or more peripheral devices 345 . For example, peripheral devices 345 may include a player identification device, such as a magnetic card reader that accepts a player-identification card issued by the casino. Peripheral devices 345 may also include a credit receiving device, such as a coin acceptor, a bill acceptor, a ticket reader, and a card reader, which may be used for placing wagers. The bill acceptor and the ticket reader may be combined into a single unit. The card reader may, for example, accept magnetic cards, such as credit cards, debit cards, and smart (chip) cards coded, i.e., cards loaded with credits or that designate an account for use via the gaming machine 300 .
According to the methodology of various example embodiments, a patron may insert a player card to provide identification information to gaming machine 300 . A player-centric rewards process, such as disclosed above, may be implemented through a player-centric rewards program stored on permanent storage accessible by the game processor or other local processor, such as a processor connected to a Bally iView or similar unit, and activated by a signal from the card reader. The player-centric rewards program may be a program or programs that may implement the process described by the flowcharts of FIGS. 1 and 2 through execution by processor 310 on gaming machine 300 .
The information from the card reader may be processed through a subroutine to determine player eligibility for player-centric rewards. If the player is determined to be eligible, then the program may decrement the value defined as the Count Limit by the number of credits wagered (or the corresponding monetary value if the Count Limit is stored as a monetary value) and update the storage register containing the Count Limit. The program may determine whether the Count Limit is less than or equal to zero. If the value reaches zero or below, then the patron may be determined by the program processing to have qualified for an award, a subroutine may be initiated to determine the award to be offered to the patron, and the Count Limit may be reset to its original value and decremented as the patron continues to play. In accordance with the program processing, the patron player level may be determined, a set of potential prizes or prize levels may be identified for which the patron's player level is eligible, and the award may be chosen from the set of potential prizes or prize levels using a random or quasi-random number generator. In an alternative embodiment, the patron's player level may be identified at the beginning of play and the set of potential prizes or prize levels may be determined for which the patron's player level is eligible, gaming machine 300 may display a message viewable by patron showing the count and/or the set of potential prizes or prize levels for which the patron is eligible. Gaming machine 300 may also provide encouragement to the patron to win an award and one of the potentially available prizes or prize levels by displaying entertaining video images and/or providing audible messages, such as cheerleaders making a ‘GO’ cheer and/or displaying a fireworks display when pre-programmed levels of play are met by a player.
Upon determining a prize or prize level that is to be offered to the patron, then an instruction from the player-centric award program may direct the processor to transmit a notification to the patron, such as by displaying an informational message on display 330 or 339 advising the patron that he has qualified for an award and providing the patron with one or more options for responding to the notification. Thereafter, the patron may receive a redemption voucher for use at an operator patron service facility or a cash disbursement, such as credits added to the credit meter or a printed cash voucher. When the patron completes play, as by removing the player card from the card reader, then the Count Limit may be reset to its original value prior to a subsequent player initiating play.
In one or more example alternative embodiments, a Count and/or Count Limit may be stored in temporary storage, such as by example one or more registers of a game microprocessor, a player interface microprocessor, digital signal processor, or controller associated with a player interface such as a Bally iView, or a processor associated with a Bally GMU or GTM which may be communicatively connected to the game motherboard and the player interface. Alternatively, the temporary storage may comprise an onboard (motherboard or daughter board) conventional memory, such as random access memory (RAM), or, an off-board connected conventional memory, such as a conventional hard-drive, or, a connected printed circuit board with a conventional processor, controller, and/or memory. The temporary storage value may be defined as the Count which corresponds to the number of credits wagered by an eligible patron during a gaming session. The processor may increment the Count by the number of credits wagered. After each play, the Count may be compared with the Count Limit in accordance with the programmed player-centric award procedure executed by game processor, when the Count is either equal to or greater than the Count Limit, the patron may then qualify for a player-centric award. The programmed player-centric award procedure may then initiate a subroutine to determine an award to be offered to the patron, the Count may be reset to zero, and the Count incrementing and comparison steps may begin again as the patron continues to wager. The award subroutine may include a variety of prize levels which may be determined in accordance with a random or pseudo-random number generator where respective of the selectable numbers correspond to respective prize levels. Once the processor determines the award to be offered, then the procedure instruction set may include an instruction for the game processor to send an award notification to the patron through, by example, display 330 or display 339 , or by printing a voucher redeemable at one of the operator facilities providing patron services. In the event of a display notification, the patron may by example be provided the option of having a redeemable voucher printed or, in the case of a cash award, of having credits uploaded onto the credit meter for further play on gaming machine 300 . Alternatively, the game processor may cause an electronic award record to be created and transmitted to a data location associable with and accessible on behalf of the patron. Such a data location may be a permanent storage connected to the gaming machine or may be a memory stick or magnetic strip connected to the patron's player card. In the case of records being stored on a patron's player card, a patron may access the award by utilizing a machine readable device for dispensing rewards or by presenting the patron's player card to an operator's representative, such as at a cashier's cage.
In one or more alternative embodiments, a Count or Count Limit may be obtained from information stored or machine readably inscribed on or about patron's player card through the use of user card interface 340 which may have a receptacle to receive player cards or may have a scanner enabling a proximity scan of the information on the patron's player card. The patron's player card may contain the information such as through the use of a memory strip. In such cases, user card interface may have a read-write capability to enable writing the ending state for the Count and/or Count Limit values at the time the patron concludes play on a given gaming session. Thus, a patron may play different gaming machines and play at different times while retaining the state of the patron's Count and being able to continue to accumulate points during each gaming session without losing the value of the Count from the prior session.
Alternatively, when the patron completes play at a given gaming machine, as by removing the player card from the gaming machine card reader, then the Count may be reset to its zero or initial value. In other words, there is no Count or Count Limit state that is saved at the end of a gaming session. Also, the Count will be re-initialized after each instance where the patron reaches the Count Limit and the game processor determines whether an award shall be offered or presented to the patron.
Referring to FIG. 4A , a simple block diagram of rewards server 450 connecting over network 406 to representative example gaming machine 300 is shown. Example rewards server 450 includes processing engine 455 connected to sweepstakes database 460 and birthday database 465 . Processing engine 455 may comprise a conventional personal computer, such as an Intel or AMD microprocessor-based computer, or, any other conventionally available computers capable of performing general purpose computing and gaming specific applications, such as Dell, Sun Microsystems or IBM computers. Databases 460 , 465 may comprise one or more conventional hard drives or other storage media for storing patron records which may be written, updated, and accessed through processing engine 455 , and, for storing programs executable by processing engine 455 . The stored programs may include one or more procedures, subroutines, or sets of coding for performing or enabling birthday, sweepstake, or other player-centric rewards processing such as are outlined in the steps of FIGS. 1 and 2 . For connecting the various devices, such as servers at the back-end and gaming machines 300 at the front end, network fabric 406 may include, but is not limited to, an IP-based local area network backbone, such as Ethernet. As may be appreciated, other functionally comparable network backbones may be utilized.
For instance, in an example system such as is shown in FIG. 4A , gaming machine 300 may utilize network interface 325 to connect with rewards server 450 through network 406 . A player card connectable through user card interface 340 to gaming machine 300 may contain sufficient information which when read such as by user card interface 340 may be used to identify a player at gaming machine 300 either directly from the information stored on the card and/or by transmitting player card identification information to query a network-connected server and database containing player records such as rewards server 450 or a separate player tracking server (not shown) and accessing a patron's player records remotely. Once the patron's records have been accessed, a query may be sent to rewards server 450 either from gaming machine 300 , a player tracking server, a host computer connected to various servers connected to the network, or other conventional network communicating device inquiring whether the patron is eligible to receive a birthday, sweepstake, or other player-centric reward. Responsive to the query, rewards server 450 may transmit a patron reward message to gaming machine 300 which may cause a message and/or video to be displayed for viewing by the patron on either an iView-type display, a main display, or other information medium, for example a speaker, apprising the patron of an available reward, possibility of a reward based on continued play, and/or providing an entertaining audio and/or video transmission.
In one example embodiment, the patron's player records including current Counts and/or Count Limits may be downloaded to gaming machine 300 from rewards server 450 , a player tracking server (not shown), or some other networked computer and/or database. As the patron proceeds to play, the Count may be incremented or decremented as discussed more fully above until the Count either matches the Count Limit or reaches zero, at which point, the patron may become eligible for a player-centric award as discussed more fully above. As also discussed above, the patron's information may be utilized to compare against possible player-centric rewards, such as a birthday award, to determine the patron's eligibility. In another embodiment, the Counts and/or Count Limits may be maintained and updated on a server, such that as a patron plays, information is sent to the server concerning each play and the Count is incremented or decremented in accordance with a procedure such as is shown and discussed more fully above with reference to FIG. 1 .
In the case of a network-connected player database and/or server accessible by one or more gaming machines 300 as through network interface 325 over network 406 , an operator may identify and rate players, either through direct data input or conventional software designed to perform the identification and rating functions on a host computer or player tracking server based upon play over a period of time. Based upon the player rating, a procedure may be implemented as with a computer module executed by rewards server processing engine 455 that associates ratings of players with operator determined tiered player levels and according to the tiered player levels establishes eligibility for player-centric rewards as discussed above. The eligibility information may by example be stored according to player tier levels in sweepstakes database 460 and/or birthday database 465 , or on an individual player basis, in a player tracking database which may be updated either in real-time or on a periodic basis through the player tracking server. When a player inserts a player card or otherwise identifies themself, a gaming machine may access and utilize the information stored on the networked system to determine the eligibility of a player for player-centric rewards. In the case where the player-centric rewards program resides on the gaming machine, then it may begin execution upon determining that the player at the gaming machine is eligible.
Alternatively, the player-centric rewards program may reside on a server, such as rewards server 450 , remote from gaming machine 300 . In which case, gaming machine 300 may simply provide the incrementing and comparison functions, and transmit a message to the server when the threshold is met for an award to be offered to a patron. For instance, when a player is identified at a gaming machine as eligible for player-centric rewards, then the player-centric rewards program may begin executing such as through processing engine 455 . The instruction set may include sending a message to the gaming machine to set and increment a counter in accordance with play by the eligible player and to send a message to the server, for example, when the Count reaches the Count Limit.
In another alternative, the gaming machine may provide game play information on a real-time basis to the server which may perform the incrementing and comparison functions, as well as the rewards processing. Upon the server determining an award to be offered, the server may create and store a record which may be associated with the patron's player information and may also send a message to the gaming machine to notify a patron of the award offer. In the case of an award offer, a patron may be required to indicate an acceptance as by pressing an ‘accept’ button or key or by entering a personal identification number (PIN). Alternatively, in each case discussed above, an award may simply be given to a patron without any acceptance required by the patron. Conditions may or may not be included with an award or award offer, such as that the patron utilize or redeem the award within a period of time which may be determined by an operator.
Continuing to refer to FIG. 4A , in one or more embodiments, user input devices 335 may include a processor, memory, and associated components as may be implemented on a printed circuit board and the Count or Count Limit may be received by this circuitry and related software for decrementing or incrementing as the case may be upon each play by the patron. In these example implementations, the wager information may be passed from microprocessor 310 or another processor with access to wagering information, in accordance with an instruction from the processor in order that the Count or Count Limit be correctly adjusted.
In one or more example embodiments, a game monitoring processor unit, such as a Bally game monitoring unit (GMU), may be implemented separate from microprocessor 310 and the processor that may be included with user input devices 335 , such as Bally's iView, but may be connected to both for receipt of gaming information and player information, respectively. In these example implementations, the Count or Count Limit may be maintained with the game monitoring processor unit and the wager information will be passed to it from or in accordance with an instruction from microprocessor 310 .
In each of the examples described above, the Count or Count Limit may be incremented or decremented by a gaming and/or one or more related processors incorporating programming to effect steps, such as in accordance with the flowchart described by example with respect to FIG. 1 . When the pre-determined number of plays is reached by the patron then a signal may be sent to display 339 ( FIG. 3B ) (incorporated with user input devices 335 ) and a celebratory show may be presented to the patron from a memory (which may be part of user input devices 335 or otherwise stored on gaming machine 300 ) to apprise the patron that the patron is eligible for an award. In the case, where gaming machine 300 is not network connected, then a random number generating program may be initiated to determine whether or what award the patron may receive, such as a sweepstakes prize, cash award, restricted credits, etc. In each of the cases described above with respect to player-centric rewards based on play, a similar program process or subroutine may be executed, such as in accordance with the flowchart described by example with respect to FIG. 2 , which includes obtaining player information, such as birthday, anniversary, etc., and comparing against the current date or the program steps may simply obtain the date and compare versus selected stored holidays to determine whether a patron may be eligible for a player-centric award other than for play.
Continuing to refer to FIG. 4A , rewards server 450 includes processing engine 455 which may communicatively connect to sweepstake database 460 and birthday database 465 . As shown, gaming machine 300 may include network interface 325 , such as one or more conventional network PCMCIA cards or a Bally ACSC NT-board, GMU, or GTM, to facilitate IP-based or address-based communication of some form with other networked devices, such as the rewards server 450 and the like. Through the network, microprocessor 310 may communicate with rewards server 450 to facilitate execution of various rewards transactions. In one or more embodiments, the network interface 325 may be used to download one or more gaming presentations or other software and/or data from the gaming server. To facilitate placement of wagers using a credit or debit card through a credit card reader (not shown) that may be connected to gaming machine 300 as by example through user input devices 335 , user card interface 340 , and/or peripheral devices 345 , network interface 325 may be used to communicate with a banking server (not depicted), which connects to a financial institution that has issued the financial card, conduct a credit card authentication process, and then credit the requested amount to gaming machine 300 . The accounting server issues credit confirmation to gaming machine 300 , which in turn allows the casino patron to place the desired wager on the machine and to proceed with the game. In a progressive gaming network environment, where several gaming machines 300 compete for a single jackpot prize, the network interface 325 may be used to communicate with other gaming machines 300 , as well as with a game monitoring server (not depicted) to synchronize a jackpot value and other parameters.
Referring to FIG. 4B , networked gaming system 401 is shown in accordance with one or more aspects of the invention wherein banks 403 of gaming machines 300 are connected to router 405 , router 405 connects to router server 407 and multiple backend subsystems 409 including player-centric rewards programming enabling the executing of slot process jobs 411 . By example, networked gaming system 401 may be conventionally architected such as with conventional Bally gaming machines and a conventionally available ACSC SMS and CMS products implemented with the IBM iSeries products with modifications to selected portions of the player tracking software to incorporate the player-centric rewards such as those described in FIGS. 1 and 2 and in the foregoing description.
Routers 405 , such as a conventionally available Bally ACSC Game Net device, may be programmed to consolidate gaming data and other communications from respective bank 403 of gaming machines 300 into packets and to transmit the packets according to the routers programming to game net server 407 and/or pre-determined portions of multiple backend systems 409 . Routers 405 may receive a notification of each transaction at their respective banks 403 , modify the information prior to transmission to router server 407 , such as a conventionally available Bally ACSC Game Net server, and selected portions of multiple backend subsystems 409 according to router 405 programming. For example, when a patron inserts the patron's card in a card reader of gaming machine 300 , the information is read from the player card and transmitted to router 405 which in turn sends the player information to selected portions of multiple backend subsystems 409 and a query may be made whether the patron is eligible for a player-centric reward, such as a birthday reward. Additionally, upon a patron playing sufficiently to match the patron's Count with the Count Limit, router 405 connected to the respective player's gaming machine 300 may be programmed to transmit a message to a rewards server, such as shown in FIG. 4A , which may be implemented as part of multiple backend subsystems 409 .
Multiple backend systems 409 , such as may be conventionally architected using Bally's ACSC SMS and CMS iSeries-based products, may be programmed to process player-centric slot process jobs 411 . The iSeries-based products implemented in the Bally architecture may include i5 server 413 , which are originally manufactured by IBM and programmed by Bally to perform networked gaming systems functions. Amongst the programming that may be implemented may be player-centric rewards programming to perform the steps described in the figures and description herein. To accomplish various networked gaming systems functions including player-centric rewards processing, multiple backend systems 409 may include slot accounting system (SLT) 415 , slot marketing system (SMS) 417 , and casino management and accounting system (CMS) 419 . Each of the respective systems may be under the centralized control of a host computer the function of which may be performed by i5 server 413 . Additionally the respective functions of systems 415 , 417 , 419 may be implemented through programming of separate servers or a single server such i5 server 413 . A workstation (not shown) may connect to i5 server 413 and may include a conventional display, keyboard, and mouse enabling an operator (user) to run respective programs associated with systems 415 , 417 , 419 and modify the operation of the respective systems through the selection of various options such as player-centric rewards criteria. For example, upon a patron inserting a player card into a gaming machine 300 connected to networked gaming system 401 , a message may be sent to i5 server 413 that contains patron information and initiates one or more slot process jobs 411 according to the programming of i5 server 413 to determine whether the patron is eligible for a birthday reward. Programming of i5 series 413 may be triggered upon receipt of the patron information that includes sending selected patron information and a query to slot marketing system 417 . In parallel, i5 series 413 may send patron and gaming machine 300 identifying information and a transaction report to slot accounting system 415 . On determination of a patron's eligibility for a birthday reward, SMS 417 may send a message to CMS 419 to make a record of the transaction and a message may also be sent from multiple backend systems 409 to gaming machine 300 notifying the patron of the birthday reward. Similarly, slot process jobs 411 may be initiated on i5 series 413 upon a patron meeting the playing criteria for eligibility for one or more player-centric rewards, such as Bally Lucky Star Power Sweepstakes Rewards.
Referring to FIG. 5 , bonus rewards control process 501 is shown via a flow diagram in accordance with one or more aspects of the invention and describes process steps which may be implemented by the programming and running of a bonus rewards program on i5 server 413 and programming various options through the user workstation, such as a Bally Control Panel (BCP). In order to access information or initiate programming activity at the workstation, i5 server 413 includes conventional security programming that upon a key being depressed on the keyboard presents a query on the display requesting a user to log in a user identification and password (step 503 ). Once an authorized user has been identified by i5 server 413 , a menu may be displayed with various options for the user to choose from. Amongst the options, one option may be to access the Sweepstakes Rewards activation controls interface program residing on i5 server 413 which user activates (step 505 ). Upon receiving the activation request, i5 server 413 executes the Sweepstakes Rewards activation controls program (step 507 ), accesses the Sweepstakes Rewards activation control database where the current settings are stored and displays the current settings (step 509 ). Once the current settings are displayed, the user can modify various of the settings by typing values or pulling down a menu of options associated with the various settings (step 511 ). When the user has completed modifications to the Sweepstakes Rewards settings, the user may press the enter button which may cause the Sweepstakes Rewards activation controls interface program to receive the input data and instruct i5 server 413 to over-write the old current settings data with the new current settings data in the Sweepstakes Rewards activation control database. Prior to over-writing the old data, i5 server 413 may respond with a security question asking if the user is sure that it wants to change the current settings. Upon the user, pressing the ‘ok’ button, i5 server 413 over-writes the old data with the new data, (step 513 ). Thereafter, when a patron qualifies for a Sweepstakes Reward, a message is sent from gaming machine 300 to i5 server 413 which causes the Sweepstakes Reward program to be executed and the Sweepstakes Reward control data to be accessed from the Sweepstakes Reward activation control database to determine the eligibility of the patron for one or more Sweepstakes Rewards.
Referring to FIG. 6 , bonus rewards control process 601 is shown via a flow diagram in accordance with one or more aspects of the invention and describes process steps which may be implemented by the programming and running of a bonus rewards program on i5 server 413 and programming various options through the user workstation. Bonus rewards control process 601 describes additional steps and options as compared to process 501 shown in FIG. 5 ; however, the programming and operation is similar in both instances.
To initiate activity at the workstation, the workstation display panel may display a request for a username and password, (step 603 ). When the workstation user enters a username and password and transmits the information, the workstation or the i5 server 413 or some other network connected device may compare the entered user information with a database to determine if the user information matches an authorized user. If the user is authorized to enter the bonus reward control application maintained by i5 server 413 , the workstation, or another network connected device, then a menu may be displayed (step 605 ) based on the level of access permitted to the user which may be determined by the information stored in the database and associated with the username. As a security measure, security programming may cause i5 server 413 to lock the keyboard and/or display in the event that an incorrect username and password is entered three times.
Amongst the selections provided by the display may be Bonusing/Sweepstakes (step 607 ) which the user may choose to select. The computer application controlling access to this option may determine whether the user is authorized to modify, add, or update, or view the Bonusing/Sweepstakes status menu (step 609 ).
If the user is not authorized, then a message may be displayed accordingly and an alert message may be sent to a security computer and/or monitor indicating that there has been an attempt to access the Bonusing/Sweepstakes status menu by an unauthorized user. If the user is authorized, then the current Bonusing/Sweepstakes status for the CMS & SMS may be displayed on the display panel (step 611 ). Depending upon the user's access level, portions of the displayed settings for Bonusing/Sweepstakes may be set for read-only while other portions may be selectable and modifiable. Alternatively, portions of the display settings which might otherwise be read-only may be provisionally allowed to be reset subject to a sign-off by a user with higher level authorization.
One way to begin adjusting Bonusing/Sweepstakes settings may be to select a player card level, (step 613 ). In accordance with the player card level, the user may select a reward from a set of allowable rewards, set the number of days to claim the reward, and set a value for the reward. Where, for example, the value may be a dollar amount which may correspond to a Count Limit to be associated with the player card level according to denominations played by the various patrons, (step 615 ). Upon entry of the new settings, the display panel may show the revised settings along with the unrevised settings, (step 617 ). The user may repeat the steps for each player card level or the user may have the opportunity to revise each card level before entering the changes.
Once the user has entered the changes, the bonus rewards processing requests the system to validate the entered data changes. The validation may be at the local level (the workstation) or may be performed by i5 server 413 or may be performed by some other network connected device depending upon which device executes the bonus rewards editing program. During the validation processing, the bonus rewards editing program may compare the settings against a local database containing permissible settings according to levels of players. In the event that a discrepancy is found, then the display panel may indicate the error and request a correction before proceeding, (step 620 ). Once the new data settings are validated at the local level, the workstation or i5 server 413 may transmit the new Bonusing/Sweepstakes data settings to rewards server 450 with an instruction to update the previous settings. The user may exit the Bonusing/Sweepstakes editing process and return to the main menu, (step 623 ).
Referring to FIG. 7 , a flowchart shows a bonusing rewards process 701 in accordance with one or more embodiments of the invention. In the instant flowchart, the user updates from FIG. 6 process have been input to rewards server 450 . As discussed earlier, in an alternative embodiment, the rewards program may be loaded on gaming machine 300 with the player information being either included in a local or remote database accessible by the gaming machine processor in order to determine eligibility, etc.
After a patron inserts his/her player card, a query may be made from the gaming machine as to whether the bonusing rewards program is active, (step 703 ), and in the case of a server based rewards program, the real-time play data may be transmitted to rewards server 450 , (step 705 ). It may be appreciated that that would be one of many types of ways to process the player information so as to be able to determine eligibility, rewards, etc. If the bonusing rewards program is active then rewards server 450 may access and process the player information to determine whether the patron's account information matches any of the rewards criteria, (step 707 ). If not, then the rewards processing with respect to the particular patron terminates or the rewards server 450 continues to receive updates on the patron's play, if a reward process is active based on Count and for which the patron may be eligible in the event of additional play. If the patron information does match the rewards criteria, then the patron's account is updated accordingly, (step 709 ). Rewards server 450 or the host computer sends an instruction to gaming machine 300 to play a show for the patron on one of the gaming machine displays and/or an associated overhead display and the patron is informed through the show and/or additional information of the reward, (step 711 ). In the case where the patron is required to take an action to accept the reward, patron may do so through the player interface associated with the gaming machine or may go to a cage to request the reward, (step 713 ). In the case where the reward has a time-limitation for redemption, the patron may be informed that the reward will expire at a pre-determined time, such as at the end of the day or week, etc., (step 715 ). Upon seeing the show, patron may simply choose to redeem the reward, such as a cash reward, by pressing the accept button to download credits to gaming machine 300 , (step 717 ). Upon redemption of a reward, rewards server 450 and/or player tracking server receives the information and the patron's account is updated accordingly.
Referring to FIGS. 8 and 8A , SMS block diagrams including transaction flow 801 are shown in accordance with one or more embodiments of the present invention. Game server 803 , such as a Bally Game Net server, may execute rewards program and communicate through floor processor 805 , such as Bally Game Net, to provide player-centric rewards at the gaming machines. Through floor processor 805 , birthday rewards messages 807 are transmitted to respective gaming machines 300 . Birthday rewards messages 807 cause keys to be activated on gaming machine 300 , such as self-comp/service keys, so that patrons may accept and pull-down cash rewards or playing credits, etc. down to their respective gaming machines.
In order to determine patron eligibility, rewards server 803 may receive data from the CMS, such as patron account information. Also, the player account information may be updated to the CMS as part of the processing performed through floor processor 805 and game server 803 when patrons are awarded and redeem rewards. Transmissions may be made as between the networked devices using TCP/IP protocols.
In one or more embodiments, three player levels 809 are utilized (although there may be more or less depending upon the users selected options) and the respective Count Limits and related reward information are transmitted as between floor processor 803 and the respective gaming machines where eligible patrons play. Upon notification if rewards, floor personnel may also be apprised as through pager dispatch 811 .
Referring to FIG. 9 , a flow diagram of player-centric rewards system 900 in accordance with one or more aspects of the invention. To initialize the player-centric rewards, an operator or user inputs the rewards process data at the workstation 901 connecting to bonus rewards server 902 . As described previously, the operator may select from various input values, which may include the denomination and corresponding Count Limit required to be played by a player before the player may be eligible for a reward, such as a Bally Lucky Star. The input data is transmitted to bonus rewards server 902 which in turn communicates through the network 903 with gaming machines 904 . When the player inserts a player card into a card reader associated with a player interface unit, gaming machine 904 sends the information to the host computer which routes the information through its network of processors and processes to determine the patron information and query bonus rewards server 902 as to the patron's eligibility. To enable the communication between the player interface unit, a player interface processor includes an executable communication instruction set operable to receive and transfer information between the player interface and the rewards server. The player interface processor may be connected to communicate directly over the network or through other processors, such as a game processor associated with the gaming machine or a network processor, such as the processor controlling a Bally GMU or GTM, which may communicatively connect with the player interface unit, such as a Bally iView, the game processor, and the rewards server.
Bonus rewards server 902 may determine if there is an immediate reward available, such as a birthday reward, and also determine whether the patron is eligible to play for player rewards and if so, may determine the Count Limit required based on the player rating or may obtain a current Count state, if the system permits accumulation of the Count during more than one playing session. The Count and Count Limit may then be transmitted to gaming machine 904 , where in the case of an ACSC CMS/SMS an NT board at the gaming machine may store the Count Limit and current Count. As the patron plays, the Count may be accumulated by a counter associated with the NT board. When the Count matches the Count Limit, a message may be sent from gaming machine 904 to floor processor 906 which in turn may transmit the information to patron management system 907 , such as the CMS including rewards server 902 , which may include the patron's identifying information and that the patron has met the play requirements for a reward, such as a Lucky Star. Patron management system 907 processes the information and based on the pre-programmed rewards and eligibility data determines the award to be offered to the patron, updates the patron's account to include the award information, and transmits message 908 to the patron through floor processor 906 and gaming machine 904 which may cause a show to be initiated on display 909 on gaming machine 904 that informs the patron of the award. Thereupon, the patron may use keypad 910 on gaming machine 904 initiate request 911 for the award to be downloaded from the patron's account and onto the credit meter of the gaming machine (in the case of a cash award). Request 911 is transmitted through floor processor 906 and to patron management system 907 where the processing system determines whether the request should be granted and takes the actions needed to comply if the request is valid.
Referring to FIG. 10-23 , screen captures of display menus are shown which may be generated at a user interface, such as a workstation connected to a host computer and/or rewards server in accordance with one or more aspects of the invention. The user interface menus shown may be accessed by a casino operator's agent at a host computer and/or related servers' user interface. The menu illustrates a data structure that may be stored and implemented in the processing engine 455 of the rewards server 450 to effectuate processing of the sweepstakes and/or birthday rewards transactions according to one or more exemplary embodiments.
An example workstation may be a Bally control panel which includes a display and keypad for use as a user interface. Authorized personnel may access the work station by entering their username and password. Depending upon the level of security access permitted by the user, the user may be able to access menus which are generated from a rewards program providing for editing.
The menu of FIG. 10 provides a user information as to the status of the rewards program on the CMS. In this example, the Bally Power Sweepstakes Rewards program is active, so that an eligible patron may accumulate a Count during the patron's gaming session or sessions and when the Count matches the Count Limit, the patron may obtain a reward, such as a sweepstakes entry. There may be multiple winners of the sweepstakes which may be determined real-time and there may be varying levels of prizes or rewards which may be obtained depending upon the sweepstakes entry. In the menu of FIG. 10 , the user is offered the option to activate controls, maintain the rewards program, exit the rewards program, or continue to another menu.
The menu of FIG. 11 presents a query to the user as to whether the rewards program is active on the CMS. In this instance the rewards program is currently active.
The menu of FIG. 12 is entitled SMS Marketing Menu which provides options for the user to select one of the marketing programs available on the CMS/SMS which in this instance include options to select either eBonus Maintenance or Power Sweepstakes Rewards. Additional options may be requested, the user may sign off, or may enter a required password for access at different levels of authorization.
The menu of FIG. 13 informs the user that the sweepstakes rewards program is not active and the provides a query asking the user if the user wishes to enter the activation controls or maintain sweepstakes rewards menu.
The menu of FIG. 14 presents a query whether the rewards program is active on the CMS. In this instance, the rewards program is not active.
The menu of FIG. 15 presents a columnar listing of the respective denominations of slot machines and sweepstakes rewards eligibility for three levels of patrons. In one or more exemplary embodiments, the processing engine 455 may be configured to recognize the three different card levels. The gaming machines 300 may have different slot denominations ranging from $0.01 to $100 (Column 1). As shown, a user may select different rewards and redemption period for each denomination and each level of player. For instance, from the example menu, it may be seen that the user has designated that the highest level players are eligible to receive a sweepstakes reward of $15 (Column 2) which is redeemable for a period of 15 days (Column 3) for playing any denomination slot machine.
On gaming machines having $0.01, $0.02 and $0.05 cent slot denominations or wagers per line played by a patron, only the highest designated card level is eligible to receive the sweepstakes reward of $15 which is available for a period of 15 days from activation of the sweepstakes reward. Zeros in Columns 3 and 4 indicate the ineligibility of the second level patrons and zeros in Columns 4 and 5 indicate the ineligibility of the third level patrons.
On gaming machines having a $0.10 denomination, only the first and second card levels may receive the sweepstakes rewards. For $0.10 denomination slot machines, the first card level patrons are eligible to receive a $15 reward available for 15 days, and the second card level patrons are eligible to receive a $10 reward available for 10 days.
For gaming machines having a $0.20 to $100 slot denomination, the first card level patrons are eligible to receive a $15 reward available for 15 days, the second card level patrons are eligible to receive a $10 reward available for 10 days, and the third card level patrons are eligible to receive a $5 reward available for 5 days. As discussed previously, in order for patrons to receive a reward, pre-determined amounts of wagers are played by the patrons and the amount of wagering required to obtain a reward may be varied according to the player level. The menu through the rewards program provides the user the opportunity to change any of the displayed values, delete any of the denomination rows, and display any updates.
In accordance with one or more embodiments, the sweepstakes rewards may become available to a casino patron as soon as the rewards are activated by the casino. In one or more embodiments, the sweepstakes rewards are available only to the casino patrons who have casino-issued user cards. Therefore, to access the sweepstakes rewards, the patron must insert his or her user card into the gaming machine 300 . If the sweepstakes rewards are available, the patron is notified of the available sweepstakes rewards. In one or more embodiments, a ‘promo’ light on the gaming machine 300 may blink as an indicator that one or more rewards is available. In another embodiment, a message may be displayed on the iView™ interface describing the sweepstakes rewards that are available. A patron may accept the reward credits by pressing a ‘Rewards Button’ on the gaming machine 300 at the time of receiving the notification or at any other time within the indicated promotional period at any gaming machine 300 within the gaming environment. Once the patron redeems the sweepstakes reward, the rewards notification message is no longer displayed to the patron on the gaming machines 300 . The rewards server 450 may maintain information about patrons who have redeemed their sweepstakes rewards in the sweepstakes rewards database 460 .
Similar to the sweepstakes rewards, the rewards system may also provides birthday rewards to the casino patrons according to one or more embodiments which may be modified using a menu similar to that shown in FIG. 15 . Processing engine 455 of rewards server 450 may be configured to implement birthday reward transactions. The birthday reward is typically made available to the casino patrons only once a year and may be cashed out only within a predetermined time period before or after the patron's birthday. The time frame for redeeming birthday rewards may be set based upon the card level of the casino patron. The birthday information relating to the casino patron may be stored in the birthday rewards database 465 . The birthday rewards information in the database 465 may be accessed based upon the patron's user ID information, which is read from the user's card and then provided to the rewards server 450 by the gaming machine 300 . To assure that the patron does not get multiple birthday rewards within any one year time period, the birthday rewards database 465 contains information on whether the given patron has redeemed his or her birthday reward.
Similar to the sweepstakes rewards, the birthday rewards amount and duration may depend on the card level of the particular casino patron. Thus, in one example, a first level card holder may receive a $15 birthday reward and have 15 days to take these credits once they become available to the patron, provided the patron inserts his user card into the gaming machine between three days before and three days after his birthday. The second level card holders may receive a $10 birthday reward and have 10 days to take these credits once they become available to the patron, provided he inserts his user card into the gaming machine between two days before and two days after his birthday. The third level card holders may receive a $5 birthday reward and have only five days to take these credits once they become available to the patron, provided he inserts his user card into the gaming machine between one day before and one day after his birthday.
The menu of FIG. 16 presents the one cent denomination Count Limit settings for the three respective levels of patrons. The rewards program also displays the maximum limit that may be entered ‘$65535’ and provides instructions to the user to make changes and view additional settings or menus. In the example menu, only the highest level patron is eligible for receiving a $15 sweepstakes reward (Column 1), which may be redeemed within 15 days (Column 2). When a reward is to be offered, select a show that will be displayed for the patron (Column 3). The number ‘59’ corresponds to a show stored on the rewards system. The second and third level patrons are not eligible for a reward for playing one cent denomination slots which is reflected by the zeros in row 2 (second level patron) and row 3 (third level patron). The user may modify any of the data and link the sweepstakes reward promotion to other rewards, bonuses, and/or promotions.
The menus of FIGS. 17 and 18 are informational pages that are generated by the rewards program to introduce the user to the sweepstakes reward program as implemented on the SMS/CMS.
The menu of FIG. 19 displays the Count Limit settings for five cent denomination slot machines and indicates that the number one rated patrons may be eligible after playing one hundred dollars of wagers. The menu also provides for the user to make changes and/or deletions to the settings which are also included with respect to gaming machine manufacturer.
The menu of FIG. 20 provides a display of the message to be presented to a patron which may be modified by a user. When a patron earns a sweepstakes reward, the message may be displayed on a player interface, such as a Bally iView, on a gaming machine where the patron is playing. The display informs the patron that the patron has earned a $15 reward which must be redeemed by a set date.
The menu of FIG. 21 displays various subroutine/function code links (Column 2) associated with the rewards program and descriptions (Column 1) which may be identified by the user to adjust settings. For instance, each card level has a separate variable associated with the amount of the reward, the number of days to claim the reward, and the show to be provided when the patron earns a sweepstakes reward.
The menu of FIG. 22 displays the SMS system values which may be modified by a user. For instance, in the example, Lucky Stars Active refers to the sweepstakes rewards as described above and the ‘Y’ indicates that ‘yes, Lucky Stars is active. The user may replace the ‘Y’ with a ‘N’ to de-activate the rewards being offered to patrons on the system. Other active and inactive features of the SMS system are shown on the display and may be modified by the user.
The menu of FIG. 23 displays a summary of sweepstakes rewards for which Card Level 1, 2, and 3 patrons are eligible that play on $0.25, $0.50, $1, and $5 denomination slot machines 300 or wager in those denominations on slot machines 300 with multiple denominations and/or amounts that may be wagered per line. The amount of the reward and the days that the reward will be available may be varied according to patron level and denomination wagered. More than one Count Limit may be maintained for an individual patron depending on the denomination played. The user may also select the particular rewards code to associate with the denomination, such as ‘Ebonus1’.
While the example embodiments have been described with relation to a gaming environment, it will be appreciated that the above concepts can also be used in various non-gaming environments. For example, such rewards can be used in conjunction with purchasing products, e.g., gasoline or groceries, associated with vending machines, used with mobile devices or any other form of electronic communications. Accordingly, the disclosure should not be limited strictly to gaming.
The foregoing description, for purposes of explanation, uses specific nomenclature and formula to provide a thorough understanding of the invention. It should be apparent to those of skill in the art that the specific details are not required in order to practice the invention. The embodiments have been chosen and described to best explain the principles of the invention and its practical application, thereby enabling others of skill in the art to utilize the invention, and various embodiments with various modifications as are suited to the particular use contemplated. Thus, the foregoing disclosure is not intended to be exhaustive or to limit the invention to the precise forms disclosed, and those of skill in the art recognize that many modifications and variations are possible in view of the above teachings.
|
Gaming systems, machines and methods are disclosed that provide various player-centric rewards to the casino patrons. The rewards may be provided across multiple games including slots, tables, keno, and any other casino game. The sweepstakes rewards may be used to promote increased play for chosen time periods, locations, and/or individual players. In addition, patrons can earn sweepstakes rewards based upon the amount of coins played at the slot machine, on the slot floor or throughout the entire casino. Furthermore, the patrons can receive a birthday reward, which may be credited to the eligible patrons on or about the patron's birth date. The rewards may be directly credited to the gaming machines using either cashable or non-cashable credits. The system facilitates patrons continuing to accrue rights toward a reward even when playing different gaming machines, or when playing machines having different denominations.
| 6
|
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a device for fastening details to walls and/or reinforcement of walls comprising wallboards, for example of gypsum, mounted to a framework, wherein the supporting parts may be studs of, for example, wood or metal. The device is to be positioned in the areas of the wallboard absent of framework parts.
[0002] When the device is provided with a cavity filling effect the indentation of the wallboards is reduced under the influence of stress.
[0003] For example, such an ability is required for backings to be tiled or otherwise coated with rigid materials which may crack and break, or when a rigid construction is required or desired.
STATE OF THE ART
[0004] The traditional method to perform fastening to wallboards of, for example, gypsum, may be to introduce plugs of plastic or rubber into predrilled apertures in the wallboard. These plugs are wedged when expanding and are forced against the edges of the wallboard in the aperture, for example when a screw having a larger diameter than the aperture usually provided in the plug is introduced therein. So called hollow wall screw anchors are also present, which are Introduced into a small aperture and expands on the rear side of the wallboard.
[0005] Screws having an elongated screw nut profile are also present. The screw nut profile may be positioned parallel to the screw and, when brought through the wallboard, extended perpendicular to the screw to receive support from the rear side of the wallboard. In one embodiment the invention can be limited to a similar range of application, which is indicated essentially with reference to FIGS. 20, 21, 22 , 23 .
[0006] One major drawback with the devices according to prior art is that they do not tolerate large forces before the material of the wallboard is breaking, because of the use of only one part of the wall.
[0007] When more rigid walls are required than normally the studs are arranged closer. Usually this imply a distance between the studs of 40 cm. To reinforce present walls removal of one wallboard is required for opening the wall to enable the introduction of more studs, which then are coated with a wallboard of normal quality. Alternatively more rigid special wallboards present on the market are selected. Then, the original distance between the studs can be used, which usually is 60 cm. Also in this case one wallboard is removed. Yet another manner is to provide the wall with an additional standard wallboard. This imply that, for example, the length of a bathroom wall usually is reduced by two times the thickness of a wallboard, which in a normal case results in two times 13 mm, i.e. 26 mm. This might cause a problem with the dimensions of the interior equipment, such as the dimensions of a bathtub to be reinstalled and consequently is not fitting in its earlier position. Yet a more extensive drawback is in this case that present water conduit connections may be found inside the wall, wherein a water leakage is undetectable, and if a leakage arise the water is forced into the wall by the impermeable layer on the surface of, for example, sanitary walls. All cases also require a large amount of work and materials and are consequently expensive. Usually, the costs for electricity and conduit installations increase if the number of studs and wallboard layers are altered in present walls.
SUMMARY OF THE INVENTION
[0008] One object of the present invention is to enable larger loads on fastening means than possible with present devices, and to enable reinforcement of the wallboards of a wall. The reinforcement device may be used for fastening exclusively or reinforcement exclusively or in combination, for example, when particularly large stress is to be managed.
[0009] The present invention uses the fact that, for example, a wall of gypsum wallboard mounted on a framework of studs comprises one wallboard on each side of a stud. The reinforcement device is in its most simple embodiment a cylinder adapted to reach through one of the wallboards from its outer side and through the space between the wallboards, which space is a result of the stud, to the inner side of the opposite wallboard. In this position the cylinder may be fastened by the means of a glued joint. Thus, a fastening means is obtained having a lever substantially increasing its ability to bear loads mounted to the free end thereof. If the direction of the forces is increased towards a vertical direction the importance of the lever-forming design of the cylinder is increasing, especially when mounted in a substantially vertical construction. The ability of the cylinder to handle forces is limited by the strength of the glued joint at the opposite wallboard and the size of the contact surface of the lead through of the front wallboard. When loaded until collapse the glued joint is breaking and/or the material at the inlet of the wallboard is crushed. The distance between the wallboards can also be of importance.
[0010] The lever is increased with the distance, which results in a more extensive resistance. The cylinder must be rigid to avoid bending thereof.
[0011] Further, the cylinder may be hollow in its length and provided with holes through the portion of the surface thereof, positioned in the space of the wall.
[0012] For example, an elastic fabric or film may further be positioned around the cylinder, which functions as a mould for expanding substances injected into the cylinder upon requirement. These force their way out through the holes and fill the mould surrounding the cylinder, wherein a rigid body casting the cylinder and sticking to and filling between the wallboards is obtained. This results in a reinforcement device increasing the rigidity of the wall and to which, for example, screws or hooks can be mounted and then loaded with extensive loads.
[0013] By increasing the area glued to the opposite wallboard and the radius of the reinforcement device at the lead through of the wallboard, the performance is increased accordingly.
[0014] According to one embodiment the device may be regarded as a cylinder with a first and a last portion having a somewhat larger diameter than the intermediate portion. This design is used to enable for the wire cloth to be winded up on the intermediate portion, wherein the wire cloth can be brought through the aperture arranged in the outer wallboard in the mounting procedure. The performance is increased with increasing end diameters of the cylinder. The glued end of the cylinder, may in every embodiment be bordered for improved adherence.
[0015] If the wall is filled with a medium, for example present types of sufficiently stabile insulation, the cylinder does not have to be surrounded by the wire cloth. Instead a space of desired dimensions can be formed in the current medium, which space is adapted for the current design of the reinforcement device.
[0016] According to one embodiment an elongated plate is mounted in the end of the cylinder, which is to be glued to the opposite wallboard. By this manner the largest possible surface can be brought through the substantially circular aperture.
[0017] According to another embodiment a further elongated plate is enclosed, which is unattached and thread onto the cylinder shaft. This plate can then be pulled towards the back side of the first wallboard and glued thereto. This will increase the strength of the wallboard and, thus, the loading capacity.
[0018] When an elongated plate is used the plates can either be positioned opposite each other, or with 180 degrees of displacement, and then be turned to an optional position in a full circle of 360 degrees as a combined unit, dependent on the direction and size of the current forces and how these, in each case, are handled in the best manner according to calculation.
[0019] In several of the different embodiments the reinforcement device can be provided with the wire cloth, and thereby with reinforcing fillings between the wallboards.
[0020] According to one embodiment, where improvement of the wall to carry horizontal pressure is desired but filling of the space between the wallboards with more than the cylinder not is desired, the portion of the cylinder not glued to the rear wallboard and the aperture through the wallboard may be formed somewhat conical. The gap formed thereby may then be filled with a hardening joint sealing compound. This construction transfers horizontal forces applied to the front wallboard also to the rear wallboard. The extracting resistance of the reinforcement device in a horizontal direction is also improved.
[0021] All cylinder tubes of fastening devices adapted for injection may be provided with an adapter unit between the internal cylinder area and a hole adapted for a screw after injection of, for example, an expanding substance.
[0022] The device may in some embodiments, especially as a straight cylinder ( 12 ) and ( 15 ) or having a reel shape ( 18 ), also be applied in solid materials, such as light concrete or hollow bricks.
[0023] The devices are then glued to the surrounding material in the entire length of the device, or a desired and possible portion thereof.
[0024] According to one embodiment one construction part may be excluded, for example a cylinder, which enable fastening to the rear wallboard. Instead a more traditional reinforcement of the front wallboard may be used.
[0025] To facilitate the mounting of the device, particularly at the hardening of glues or joint compounds if used, a fixing device associated to the device may be used. This comprises of a substantially circular cone having a peg, which can be inserted in the aperture 16 .
[0026] The cone is provided with a larger diameter than the device so that it is supported by surrounding surfaces, to which it temporarily can be fastened by the means of glue and/or a pin.
[0027] It may also be provided with filling spacers to compensate for differences in diameter. Such a spacer may also be mounted permanently.
[0028] If there is space filling means, for example mineral wool insulation in the wall, and removal of this is desired a space clearing tool developed for the device may be used. The tool comprises a bar having a pivoted front portion provided with a cutter. This tool is inserted through an aperture in the wallboard and is heavily rotated, for example by the means of a drilling machine. The pivoted portion is extended and clears a space having a radius corresponding to the length of the pivoted portion and a space length corresponding to how far the tool is inserted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings are labelled: Fig . . . , and a number, and shall be read in the order stated. The numerical order may be reversed.
[0030] The invention will now be described in more detail with reference to the accompanying drawings, in which
[0031] [0031]FIG. 1 is a schematic side view in longitudinal section of the device according to one embodiment as a straight cylinder mounted in a wallboard coated timber frame wall.
[0032] [0032]FIG. 1F (F refer to a front view=the outside of a wall) illustrates the device from the front.
[0033] [0033]FIG. 2 is a longitudinal section view from above of the device in FIG. 1.
[0034] [0034]FIG. 3 is a schematic side view in longitudinal section of the device according to one embodiment as a straight cylinder and provided with a joint lead through of the wallboard.
[0035] [0035]FIG. 3F illustrates the device in FIG. 3 from the front.
[0036] [0036]FIG. 4 is illustrates the device in FIG. 3 from above.
[0037] [0037]FIG. 5 is a schematic side view in longitudinal section of the device according to one embodiment as a straight cylinder, having a conical end portion, mounted in a wallboard coated stud frame wall.
[0038] [0038]FIG. 5F illustrates the device in FIG. 5 from the front.
[0039] [0039]FIG. 6 is a longitudinal section view from above of the device in FIG. 5.
[0040] [0040]FIG. 7 is a schematic side view in longitudinal section of the device according to one embodiment similar to a reel.
[0041] [0041]FIG. 7F illustrates the device in FIG. 7 from the front.
[0042] [0042]FIG. 8 illustrates the device in FIG. 7 from above.
[0043] [0043]FIG. 10 is a schematic side view in longitudinal section of the device according to an embodiment similar to FIG. 7, but joint compound has been applied, for example an expanding substance.
[0044] [0044]FIG. 9F illustrates the device in FIG. 9 from the front.
[0045] [0045]FIG. 9 illustrates the device in FIG. 10 from above.
[0046] [0046]FIG. 15 and FIG. 16 is a schematic side view in longitudinal section of the device according to one embodiment, in which the rear portion of the device is elongated and as large as possible for insertion through the aperture of the front wallboard. The movable part, which is similar to the rear portion and can be pulled along the cylinder to the rear side of the front wallboard, is also illustrated. Further, the cylinder body and the portion filling the lead through in the wallboard is illustrated.
[0047] [0047]FIG. 15F illustrates the device in FIG. 15 and FIG. 16 from the front.
[0048] [0048]FIGS. 11 and 12 illustrates the device in FIG. 15 and FIG. 16 from above.
[0049] [0049]FIG. 18 illustrates the same device as in FIG. 15 and FIG. 16 provided with 27 and injected with 26 .
[0050] [0050]FIG. 18F illustrates the device in FIG. 15 and FIG. 16 from the front.
[0051] [0051]FIG. 14 illustrates the device in FIG. 15 and FIG. 16 from above.
[0052] [0052]FIG. 13 is a schematic view from above illustrating the conversion of FIG. 15 to FIG. 17.
[0053] [0053]FIG. 17F illustrates FIG. 17 from the front.
[0054] [0054]FIG. 19 illustrates the device in FIG. 17 from the side and provided with 27 , 26 .
[0055] [0055]FIG. 19F illustrates FIG. 19 from the front.
[0056] [0056]FIG. 20 is a schematic side view of the device illustrated without the cylinder and having one plate pulled towards 30 . This design of the device reinforces and fastens in one wallboard only, namely the one closest to the fastening means.
[0057] [0057]FIG. 21 illustrates the device in FIG. 20 from the side in a contracted position.
[0058] [0058]FIG. 22 illustrates the device in FIG. 20 from the front.
[0059] [0059]FIG. 23 illustrates the device in FIG. 21 from above.
DESCRIPTION
[0060] With reference to FIG. 1 the reinforcement device is illustrated as a straight and possibly solid cylinder body 12 arranged between wallboards 10 . This design is adapted to be utilized for the fastening of fastening means, such as screws, to fasten loads acting in a substantially perpendicular direction in relation to the longitudinal section. The cylinder body 12 comprises an aperture 16 for fastening means, which aperture 16 is arranged along the centre of the cylinder body 12 . The cylinder body further comprises a bordered end 13 , a fixing pin 22 to protrude into a rear wallboard 10 , which fixing pin 22 is projecting from one end of the cylinder body 12 , and a glued joint 14 . An area of a wallboard lead through 15 , or envelope surface of the cylinder body 12 , is illustrated in FIG. 1. FIG. 1F illustrates the device from the front, i.e. from the outside of the construction, which normally is a wall. FIG. 2 illustrates the device from above, wherein a stud 11 also is indicated.
[0061] An aperture is arranged in the front wallboard 10 , wherein the cylinder body 12 provided with the glued joint 14 can be introduced and fastened to the rear wallboard 10 .
[0062] With reference to FIG. 3 the reinforcement device is illustrated as a cylinder body 12 provided with a glued joint 14 at one portion of the cylinder body 12 to be positioned at the front wallboard 10 . This design is adapted for utilization in connection with the fastening of fastening means, such as screws, to fasten loads acting in a substantially perpendicular direction in relation to the longitudinal section. However, the glued joint 14 contributes to a certain extent to the distribution of horizontal forces acting upon the wallboard, and to increase the extraction resistance of the reinforcement device in a horizontal plane. For example, the cylinder body 12 comprises a bordered cylinder surface 24 at the wallboard lead through area 15 . FIG. 3F illustrates the device from the front, i.e. from the outside of the construction, which usually is a wall. FIG. 4 illustrates the device from above. An aperture is arranged in the front wallboard, wherein the cylinder body 12 provided with the glued joint 14 can be inserted and fastened to the rear wallboard and the lead through.
[0063] With reference to FIG. 5 the reinforcement device is illustrated as a cylinder body 35 having a conical end portion. When a tapered lead through 36 and the glued joint 14 is arranged, this embodiment is adapted to be used for the fastening of fastening means, such as screws, to fasten loads acting in a substantially perpendicular direction in relation to the longitudinal section. However, the glued joint contributes to the distribution of horizontal forces acting upon the wallboard, and increases the extraction resistance of the reinforcement device in a horizontal plane. FIG. 5F illustrates the device from the front, i.e. from the outside of the construction, which usually is a wall. FIG. 6 illustrates the device from above.
[0064] The mounting is performed as in FIG. 3, with the addition of the tapered aperture 36 and that the cylinder body 12 is changed to cylinder body 35 .
[0065] With reference to FIG. 7 the reinforcement device is illustrated as a reel-shaped hollow cylinder body 18 . The reel-shape is used when a thinner intermediate portion is desired. When the rear bordered portion 20 of the reel-shaped cylinder and the wallboard lead through area 15 is formed with a larger surface, this embodiment for the fastening of fastening means, such as screws, to fasten loads acting in a substantially perpendicular direction in relation to the longitudinal section, will carry larger loads. A glued joint 25 between a front portion 23 of the reel-shaped cylinder 18 and the front wallboard 10 contributes to the distribution of horizontal forces acting upon the wallboard and the extraction resistance of the reinforcement device in a horizontal plane will increase by using a larger bordered rear portion 20 . When a reel-shaped hollow cylinder body 18 is used, this may be provided with a reduction plug 21 having an aperture for fastening means. For example, the cylinder body 18 comprise holes 19 . FIG. 7F illustrates the device from the front, i.e. from the outside of the construction, which construction usually is a wall. FIG. 8 illustrates the device from above.
[0066] The mounting is performed as in FIG. 3, but the straight cylinder body 12 is changed to a reel-shaped cylinder body 18 and the glued joint 14 is changed to the glued joint 25 .
[0067] With reference to FIG. 10 the reinforcement device is illustrated as a reel-shaped cylinder body 18 . The reel-shape is used when a thinner intermediate portion is desired. An elastic wire cloth 27 , or another suitable medium, can be applied to this intermediate portion when an expanding joint compound 26 is intended to be used. After the wire cloth 27 , which can be compared to a portion of a very elastic stocking, is thread onto the thinner intermediate portion of the cylinder body, the cloth is glued at the, points 29 with, for example, a fast hardening glue of a conventional hot-melt type of glue. This is performed to enable filling of the mould with joint compound, such as polyurethane foam, and preventing it from flowing out thereof. When the rear bordered portion 20 of the reel-shaped cylinder and the wallboard lead through area 15 is formed with a larger surface, this embodiment for the fastening of fastening means, such as screws, to fasten loads acting in a substantially perpendicular direction in relation to the longitudinal section, will carry larger loads. A glued joint 25 and the joint compound 26 contributes to the distribution of horizontal forces acting upon the wallboard and the extraction resistance of the reinforcement device in a horizontal plane will increase by using a larger 20 and the joint compound 26 . When 18 is used, this may be provided with a reduction plug 21 . FIG. 9F illustrates the device from the front, i.e. from the outside of the construction, which usually is a wall. FIG. 9 illustrates the device from above when applying the joint compound 26 by the means of a nozzle 28 . Mounting procedure: An aperture adapted for the cylinder body 18 is arranged in the front wallboard. The diameter of the aperture shall correspond to the front portion 23 and the rear portion 20 of the reel-shaped cylinder. Glue or joint compound for the joints 14 and 25 is applied. A wire cloth 27 is thread onto the intermediate portion of the cylinder. The cylinder body is brought into the aperture of the front wallboard and is glued to the rear wallboard. The cylinder and the mould is filled with, for example, polyurethane foam 26 .
[0068] With reference to FIG. 15 and FIG. 16 the reinforcement device is illustrated in a side view of the device according to one embodiment, in which the rear portion of the device is elongated and as large as possible to be brought through the insertion aperture in the front wallboard 10 . Further, the movable part is illustrated, which is similar to the rear portion, and can be pulled along the cylinder to the rear side of the front wallboard. Further, the cylinder body and the portion filling the wallboard lead through is illustrated. The cylinder body 32 , having its front portion 30 and its rear portion 31 , forms a rigidly assembled unit. In FIG. 15 the front portion 30 is connected with the front wallboard 10 by the means of the glued joint 25 and the rear portion 31 is connected with the rear wallboard 10 by the means of the glued joint 14 . The tapered sides of the front portion 30 provides a supporting part, particularly when a movable part 34 is pulled against the rear side of the front wallboard. The remaining sides of the front portion 30 are not tapered. This is due to that these surfaces are expected to substantially distribute forces perpendicular to 15 . Thus, horizontal forces acting to move the fastening device are avoided. The elliptic shape of a rear cylinder portion 31 and the movable part 34 contributes to give maximum surface to those portions which are to be brought through the aperture in the front wallboard. In turn this results in maximum reinforcement and fastening capacities. The size of 30 is also important for these capacities. Further, pull-strings 33 are arranged on each side of the cylinder, wherein the movable part 34 rotates when the pull-strings are winded around the cylinder and 34 is pulled along the cylinder to its front position against 30 . FIG. 16 illustrates the movable part 34 connected with the front wallboard 10 by the means of the glued joint 14 .
[0069] [0069]FIG. 15F illustrates the device in FIG. 15 and FIG. 16 from the front.
[0070] [0070]FIG. 11 and FIG. 12 illustrates the device in FIG. 15 and FIG. 16 from above.
[0071] Mounting procedure: The combined unit 30 , 32 , 31 , having the movable part 34 arranged adjacent to the rear portion 31 , is inserted into the aperture adapted to the front portion 30 . The aperture adapted to 30 may, for example, be arranged with a conventional hole cutter and tapered by the means of a file to fit the elliptic shape of 30 . The elongated plates 31 and 34 are held in a parallel position and are inserted into the aperture with the portion extending the most from the central axis of the cylinder first. The rear portion 31 is already provided with glue and is glued to the rear gypsum wallboard, and in occurring cases to the glued joint 25 on the portion 30 , and on the part 34 glued to the rear side of the front wallboard. This latter glue is also gluing the front portion 30 to the movable part 34 . The combined unit described above is pressed against the rear gypsum wallboard and is fastened thereto by the means of the fixing pin 22 . As a result the movable part 34 can be pulled into position by the means of the pull-strings 33 , see FIG. 16. Locking means can now be threaded onto the pull-strings, which may be permanent or in position only until the joints are hardened. If a hollow cylinder body is used the holes thereof can, if required, be reduced by the means of an adapter 21 . If filling with joint compound 26 is intended as is illustrated in FIG. 18, this is injected before sealing with 21 takes place.
[0072] [0072]FIG. 18 illustrates the same device as in FIG. 15 and FIG. 16 but provided with the elastic wire cloth 27 and injected with joint compound.
[0073] This increase the capacity of the reinforcement device to give, for example, a wall increased ability to bear larger horizontal and vertical forces in the area affected by forces, which in turn acts upon the fastening means.
[0074] [0074]FIG. 18F illustrates the device in FIG. 18 from the front.
[0075] [0075]FIG. 14 illustrates the device from above.
[0076] Mounting procedure: The same as described with reference to FIGS. 15 and 16 with the addition that the wire cloth 27 is threaded before the parts 34 and 31 are brought together. Fastening of the wire cloth to the mentioned parts is also required, suitably by a conventional fast hardening hot-melt, to be stretched when 34 is pulled into position against the rear side of the front wallboard. See FIGS. 18, 18F and 14 .
[0077] [0077]FIG. 13 illustrates how the reinforcement device has been mounted according to FIG. 17, wherein the unattached part 34 has been brought to rotate 180 degrees. The instructions of FIGS. 15 and 16 is followed, but with the difference that the pull-strings 33 are winded half way around the cylinder body. When 34 is pulled into position against the rear side of the front wallboard, 34 rotates a half turn.
[0078] [0078]FIG. 19 illustrates a case when the injection of joint compound 26 Is continued. This must be prepared by the mounting of wire cloth 27 before 34 is brought together with 31 , before the insertion through the aperture arranged in the front wallboard. Since 34 will rotate a half turn 31 and 34 must be kept in this final position when the wire cloth is fastened, suitably with a fast hardening hot-melt. Suitable fastening points are:
[0079] See FIGS. 19 and 19F.
[0080] 1. fold the wire cloth and fasten it to 34 , close to the cylinder body but not against it.
[0081] 2. fold the wire cloth and fasten it to 31 , one fastening point, at the rounded end, close to the cylinder body.
[0082] 3. pull the wire cloth over the corners of 31 and fasten it thereto.
[0083] The wire cloth is now fastened in four points and is resting upon the cylinder body when the reinforcement device is mounted to the wall, and can receive polyurethane foam for example.
[0084] With reference to FIG. 20 the reinforcement device is illustrated without the cylindrical intermediate portion. The rear wallboard is rectangular, or substantially rectangular. An aperture having a suitable size, adapted for fastening fastening means 37 and the plate 38 , is arranged in the front wallboard. The device can be turned in an optional direction in a full circle of 380 degrees. The edges of the aperture is tapered to fit to 30 , or alternatively an unattached front portion. The plate 38 is provided with glue and connected with 30 , which can be provided with glue 25 , through the pull-strings 33 . The plate is brought into the aperture, which among other things is possible by the length and flexibility of the pull-strings. The unattached portion 30 is inserted into the aperture and is filling it up. The plate 38 is pulled together with 30 and the rear side of the front wallboard, and can be fastened thereto by the means of locking means threaded onto the pull-strings. Except FIG. 20, illustrating the reinforcement device in this form from the side when positioning 30 , having its elliptic front with the larger diameter, horizontally, FIG. 21 illustrates the device from the side when it is pulled together and otherwise positioned as illustrated in FIG. 20. FIG. 22 illustrates the device positioned as described in FIG. 20 from the front. FIG. 23 illustrates the device positioned as in FIG. 20 from above.
[0085] If space filling means, such as mineral wool insulation, is present in the wall and the removal of this is desired a space clearing tool developed for the device may be used. The tool comprises a bar having a pivoted front portion provided with a cutter. This tool is inserted through an aperture in the wallboard and is heavily rotated, for example by the means of a drilling machine. The pivoted portion is extended and clears a space having a radius corresponding to the length of the pivoted portion and a space length corresponding to how far the tool is inserted.
[0086] To facilitate the mounting of the device, particularly at the hardening of glues and joint compounds, a fixing device associated to the device may be used. This comprise of a substantially circular cone having a peg, which can be inserted in the aperture 16 .
[0087] The cone is provided with a larger diameter than the device so that it is supported by surrounding surfaces to which it temporarily can be fastened by the means of glue and/or a pin. It may also be provided with filling spacers to compensate for differences in diameter. Such a spacer may also be mounted permanently.
[0088] The device can in some of the embodiments, particularly as a straight cylinder 12 and 35 or having a somewhat reel-shape 18 , also be applied to solid materials, such as light concrete or hollow bricks. The devices are then glued to the surrounding material in the entire length of the device, or a desired and possible portion thereof.
|
The invention relates to a reinforcement device for fastening, in this context, tremendous loads to particularly weaker walls of the type wallboard coated stud frame, and to contribute to the ability of walls to resist horizontal forces. The reinforcement device comprises portions, which connect and reinforce the parts of the wall construction. Thus, exceeding a materials tensile strength can be avoided, and the forces are distributed over a larger area, wherein the resistibility thereof can be summarised to a larger resistance. In a certain embodiment the reinforcement device can be used for fastening in solid constructions, such as light concrete and hollow brick constructions.
| 5
|
BACKGROUND
This disclosure relates generally to gas turbines and, more specifically, to flexible chordal hinge seals for sealing turbine nozzles within a gas turbine.
In a gas turbine, hot gases of combustion flow from combustors through first-stage nozzles and buckets and through the nozzles and buckets of follow-on turbine stages. The first-stage nozzles include an annular array or assemblage of cast nozzle segments, each including one or more nozzle stator vanes per segment. Each first-stage nozzle segment also includes inner and outer band portions spaced radially from one another. Upon assembly of the nozzle segments, the stator vanes are circumferentially spaced from one another to form an annular array between annular inner and outer bands. An outer shroud or retaining ring coupled to the outer band of the first-stage nozzles supports the first-stage nozzles in the gas flow path of the turbine. An annular inner support ring is engaged by the inner band and supports the first-stage nozzles against axial movement.
In an exemplary arrangement, forty-eight cast nozzle segments are provided with one vane per segment. The annular array of segments are sealed one to the other along adjoining circumferential edges by side seals. The side seals form a seal between high and low pressure regions by extending radially inwardly of the inner band and radially outwardly of the outer band. The high pressure region is found in the compressor discharge air, and the low pressure region is found in the hot gases of combustion of the hot gas flow path.
The nozzle segments also include inner and outer chordal hinge seals. The inner chordal hinge seals are used to seal between the inner band of the first-stage nozzles and an axially facing surface of the inner support ring. Each inner chordal hinge seal includes an inner rail extending radially inwardly from the inner band portion and a projection extending along the inner rail that runs linearly along a chord line of the inner band portion of each nozzle segment. This projection lies in sealing engagement with the axially opposite facing sealing surface of the inner support ring. The inner chordal hinge seals also act as hinges to allow the first-stage nozzles to move forward and aft as the inner support ring and the compressor discharge case undergo thermal expansion.
In addition, the outer sidewall chordal hinge seals are used to seal between the outer band of the first-stage nozzles and an axially facing surface of the outer shroud. Each outer chordal hinge seal includes an outer rail extending radially outwardly from the outer band portion and a projection extending along the outer rail that runs linearly along a chord line of the outer band portion of each nozzle segment. This projection lies in sealing engagement with the axially opposite facing sealing surface of the outer shroud. The outer chordal hinge seals also act as hinges to allow the first-stage nozzles to move forward and aft as the outer support ring or shroud and the compressor discharge case undergo thermal expansion.
During operation and/or repair of the first-stage nozzle, it has been found that both the outer and inner chordal hinge seals tend to experience warpage due to temperature differences across their rails. In particular, the seals tend to bow aft in the center and bow forward on the intersegment ends of the rails. Such warpage can cause gaps to form between the inner and outer chordal hinge seals and the respective sealing surfaces of the inner support ring and the outer shroud. These gaps can enable leakage of the compressor discharge cooling air into the hot gas flow path. This leakage can lead to problems such as increased production of NOx pollutants, hot gas ingestion past the chordal seals, and higher flowpath aero losses, which result in a lower heat rate.
Currently, supplemental seals are employed at the interface of the first-stage nozzles and the inner support ring/outer shroud to reduce the leakage flow past the chordal hinge seals. However, the use of such supplemental seals significantly adds to the complexity and cost of manufacturing gas turbines. A need therefore exists to develop a way of minimizing the leakage of fluid past the inner and outer sidewall chordal hinge seals without significantly increasing the cost and complexity of manufacturing gas turbines including such seals.
SUMMARY
Disclosed herein are gas turbine systems having flexible chordal hinge seals. According to an embodiment, a turbine system comprises: a nozzle segment comprising a stator vane extending between an inner band segment and an outer band segment; an inner support ring adjacent to the inner band segment; and an inner chordal hinge seal in operable communication with the nozzle segment, the inner chordal hinge seal comprising a flexible inner rail extending inwardly from the inner band segment, the inner rail having a projection for sealingly engaging the inner support ring.
In another embodiment, a turbine system comprises: a nozzle segment comprising a stator vane extending between inner and outer band segments; an outer shroud adjacent to the outer band segment; and an outer chordal hinge seal in operable communication with the nozzle segment; the outer chordal hinge seal comprising a flexible outer rail extending outwardly from the outer band segment, the outer rail having a projection for sealingly engaging the outer shroud.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the Figures, which are exemplary embodiments, and wherein the like elements are numbered alike:
FIG. 1 is a schematic elevational view of a section of a gas turbine;
FIG. 2 is a schematic perspective view of a flexible chordal hinge seal for use in a gas turbine;
FIGS. 3-5 are perspective views from different angles of a flexible chordal hinge seal attached to a nozzle segment of a gas turbine in accordance with various embodiments; and
FIG. 6 is a schematic side elevational view of an embodiment of a section of a gas turbine that includes a first stage nozzle including the choral hinge seals described herein.
DETAILED DESCRIPTION
Turning to FIG. 1 , an exemplary embodiment of a section of a gas turbine 10 is shown. Turbine 10 receives hot gases of combustion from an annular array of combustors (not shown), which transmit the hot gases through a transition piece 12 for flow along an annular hot gas path 14 . Turbine stages are disposed along the hot gas path 14 . Each stage comprises a plurality of circumferentially spaced buckets mounted on and forming part of the turbine rotor and a plurality of circumferentially spaced stator vanes forming an annular array of nozzles. For example, the first stage includes a plurality of circumferentially-spaced buckets 16 mounted on a first-stage rotor wheel 18 and a plurality of circumferentially-spaced stator vanes 20 . Similarly, the second stage includes a plurality of buckets 22 mounted on a second-stage rotor wheel 24 and a plurality of circumferentially-spaced stator vanes 26 . Moreover, the third stage includes a plurality of circumferentially-spaced buckets 28 mounted on a third-stage rotor wheel 30 and a plurality of circumferentially-spaced stator vanes 32 . Additional stages can be present if needed. The stator vanes 20 , 26 , and 32 are mounted to a turbine casing, while the buckets 16 , 22 , and 28 and wheels 18 , 24 , and 30 form part of the turbine rotor. Between the rotor wheels are spacers 34 and 36 , which also form part of the turbine rotor. It will be appreciated that compressor discharge air is located in a region 37 disposed radially inwardly and radially outwardly of the first stage and that such air in region 37 is at a higher pressure than the pressure of the hot gases flowing along the hot gas path 14 . As used herein, “radially inwardly” is defined as extending in a radial direction toward a center axis of the turbine defined by a turbine shaft, and “radially outwardly” is defined as extending in a radial direction away from the center axis of the turbine
Referring to the first stage of the turbine 10 , the first-stage nozzles include nozzle segments and stator vanes arranged in an annular array of stator segments disposed between inner and outer bands, respectively, which are supported from the turbine casing (not shown). Thus, each nozzle segment includes one or more stator vanes 20 that extend between inner and outer band segments 38 and 40 , respectively. An outer shroud 42 for securing the first-stage nozzles is in operable communication with the turbine casing and the outer band segment 40 . This outer shroud 42 includes an axially facing surface in axial opposition to a surface of the nozzle segment. The interface between these two surfaces includes a flexible or compliant outer chordal hinge seal. Likewise, an inner support ring 44 for securing the first-stage nozzle against axial movement is in operable communication with the inner band segment 38 . The inner support ring 44 includes an axially facing surface in axial opposition of a surface of the nozzle segment. The interface between these two surfaces includes an inner chordal hinge seal 52 . It is intended that when the turbine 10 is in operation, the outer and inner chordal hinge seals form seals between the high pressure compressor discharge air in the region 37 and the lower pressure hot gases flowing in the hot gas path 14 .
The inner and outer flexible chordal hinge seals have the same or similar designs. An exemplary embodiment of a chordal hinge seal that can serve as both the inner and the outer chordal hinge seal is illustrated in FIGS. 2-4 , which are views of the chordal hinge seal from different angles. The chordal hinge seal includes a flexible rail 100 extending from a band segment 102 . The thickness of the rail 100 is greatly reduced compared to that of prior art chordal hinge seal rails. In the case of the inner chordal hinge seal design, the inner rail extends inwardly from the inner band segment, whereas in the case of the outer chordal hinge seal design, the outer rail extends outwardly from the outer band segment. As used herein, “radially inwardly” is defined as extending in a radial direction toward a center axis of the turbine defined by a turbine shaft, and “radially outwardly” is defined as extending in a radial direction away from the center axis of the turbine. The rail 100 of the chordal hinge seal includes a chord-wise, linearly extending projection 106 for sealingly engaging with the retaining ring/inner support ring.
In order to minimize or prevent leakage flow from the high pressure region to the low pressure region of the hot gas path, the rail 100 is rendered flexible. As shown, the flexibility of rail 100 can be optimized by varying the fillet 104 radius of curvature across the rail 100 . The fillets 104 near the intersegment ends of the rail are shaped to mate with intersegment ends of other rails. Thus, the rails can be formed into an annular array of rails. Each intersegment end of the rail 100 can have a seal slot 108 shaped to mate with a seal of the intersegment end of an adjacent rail in the annular array. As defined herein, a “fillet” is a material shaped to ease an interior corner. The fillets 104 are disposed in corners between the band segment 102 and the rail 100 . The fillets 104 , which are desirably concave in shape, can be formed by various methods such as by welding the fillets 104 into the junctures or cast molding the fillets 104 together with the rail 100 and the band segment 102 .
The fillets 104 can be used to vary the stiffness of the rail 100 along its length, thereby allowing mechanical loads to overcome thermal distortions across the rail 100 that can occur during the operation of the turbine. Due to the positioning of the fillets 104 near the ends of the rails, the juncture between the center of the rail 100 and the band segment 102 has a smaller radius of curvature than the juncture between the end of the rail 100 and the band segment 102 . Moreover, the radius of curvature of each fillet 104 can increase as the fillet 104 approaches the end of the rail 100 . This change in the radius of curvature along the rail 100 is used to maximize the flexibility of the rail 100 near its center where aft thermal bowing would otherwise be greatest and to minimize flexibility of the rail 100 near its ends where forward bowing would otherwise be greatest. Minimizing the flexibility of the rail 100 at its ends also allows the ends to seal against adjacent rails even under worst case tolerance conditions. Thus, an intersegment seal at the end of an adjacent rail would fit within the intersegment seal slot 108 . FIG. 5 is a simple drawing that better illustrates the arrangement of the fillets 104 near the intersegment ends of the rail 100 .
The flexibility of the chordal hinge seals is advantageously achieved without significantly adding to the complexity and cost of manufacturing the gas turbine. Due to this flexibility, more effective seals are formed between the high pressure compressor discharge region and the low pressure hot gas flow path. As a result, less leakage of gas past the seals can occur during operation of the turbine despite the presence of thermal variations across the seals. Consequently, aero losses in the hot gas flow path are reduced such that the heat rate of the turbine is improved, and lower quantities of NOx pollutants, e.g., NO and NO 2 , are produced by the turbine. Hot gas ingestion past the seals is also reduced, resulting in durability improvements to the nozzle, shroud, and inner support ring.
FIG. 6 depicts an exemplary embodiment of a section 500 of a gas turbine illustrating a first stage nozzle that includes the flexible chordal hinge seals described herein. Hot gases of combustion flow from a combustor (not shown) through transition piece 510 . The hot gases enter the first stage nozzle 520 , impinging on airfoil 430 . The hot gases are directed by the airfoil 430 to the first stage bucket 540 . The directing process performed by the nozzles also accelerates gas flow resulting in a static pressure reduction between inlet and outlet planes and high pressure loading of the nozzles. Retaining ring 300 includes forward circumferential land 330 and aft circumferential land 325 . Retaining lugs 440 , 445 (one shown) of the outer sidewall 420 for each first stage nozzle fit into annular groove 320 . Retaining pins 490 , 495 (one shown) fit through axial holes 345 and 350 in the aft retaining land 325 and the forward retaining land 330 , respectively. The retaining pins 490 , 495 provide radial and circumferential support for the first stage nozzle 520 through retaining lugs 440 , 445 . Chordal hinge rail 460 on the outer sidewall 420 provides axial support for the nozzle at the point of the chordal hinge seal 465 making contact with the shroud 550 for the first stage bucket 540 . Chordal hinge rail 470 on the inner sidewall 410 provides axial support for the nozzle at the point of chordal hinge seal 475 making contact with the support ring 580 . Retaining pins 490 , 495 are prevented from backing out from the retaining lugs 440 , 445 by chordal hinge rail 460 .
As used herein, the terms “a” and “an” do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Reference throughout the specification to “one embodiment”, “another embodiment”, “an embodiment”, and so forth means that a particular element (e.g., feature, structure, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments. Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs.
While the invention has been described with reference to exemplary 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 this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
|
Gas turbine systems having flexible chordal hinge seals are provided. According to an embodiment, a turbine system comprises: a nozzle segment comprising a stator vane extending between an inner band segment and an outer band segment; an inner support ring adjacent to the inner band segment; and an inner chordal hinge seal in operable communication with the nozzle segment, the inner chordal hinge seal comprising a flexible inner rail extending inwardly from the inner band segment, the inner rail having a projection for sealingly engaging the inner support ring.
| 5
|
BACKGROUND OF THE INVENTION
1. Field Of The Invention
The present invention relates generally to line printers with interchangeable type carriers and, more particularly, to a system for discriminating the kind of type carrier loaded on such a line printer.
2. Description Of The Prior Art
As is well known, there are a variety of type carriers, such as type belts, type trains and type drums. The present invention can be applied to all sorts of type carriers. However, for purposes of explanation, the present invention is described with reference to the type belt carrier.
As is well known in the art, type belts are classified according to the number of characters provided thereon, the distance between adjacent types (hereinafter referred to as "the type pitch"), the size of the types, and the type code. However, the present invention is described with reference to the number of charaqters on the type belt and, in one modification, to the type pitch.
In the case of a 48-character type belt, the type belt may have a plurality of type sets, each comprising 48 characters. On the type belt, type marks are provided below the respective types and a synchronizing mark indicating the beginning of the type set is also provided.
In order to discriminate the type belt being used, a method has been proposed where the number of characters between synchronizing marks is counted. However, such a discrimination method exhibits deficiencies in that the discrimination time is relatively long, it is necessary to provide a counter having a count capacity equal to or greater than the maximum number of characters, and the arrangement of the device to implement such a method is intricate. This method was disclosed in Mayo, R. F., "Print Element Character Set Status Logic", IBM Technical Disclosure Bulletin, Volume 16, No. 6, Nov. 1973, pp. 1937-1938.
Another method for discriminating the type belt being used is disclosed in U.S. Pat. No. 3,899,968 to McDevitt, issued Aug. 19, 1975. This method uses a plurality of synchronizing marks at the beginning of the character set on the type belt to provide an identification tag. The identification tag is read from the belt into a shift register and then provided to an identification register, whose output is compared in a comparator with the verification tag provided by a verification register. Printing is allowed to take place only when the verification tag is identical to the identification tag. This method exhibits deficiencies in that a considerable amount of logic circuitry is needed to provide the desired identification function due to the use of the relatively complex binary coded identification tag.
Other prior art methods which provide an indication of the beginning of the font of a type belt or type drum are found in, respectively, U.S. Pat. No. 3,875,545 to Curtiss, issued April 1, 1975, and U.S. Pat. No. 3,117,514 to Doersam, issued Jan. 14, 1964. However, neither of these systems disclose a type belt idenification capability.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to eliminate the above-described difficulties accompanying the prior art, and to readily discriminate the kind of type carrier loaded on a line printer.
The specific feature of the invention resides in that a discrimination mark or discrimination marks specifying the kind of a type carrier are provided thereon, and the position of the discrimination mark or the number thereof, employed as discrimination factor, is detected to determine the kind of the type carrier.
DETAILED DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, advantages and features of the invention will be better understood from the following detailed description with reference to the accompanying drawings, in which:
FIGS. 1(a)-1(d) are plan views of type belts of 48, 64, 96 and 128 characters, respectively, according to a first embodiment of the invention;
FIG. 2 is a block diagram of the discriminating circuit according to the first embodiment;
FIG. 3 is a timing diagram illustrating the operation of the discriminating circuit shown in FIG. 2;
FIG. 4 is a logic diagram of the mark recognizing circuit used in the discriminating circuit shown in FIG. 2;
FIG. 5 is a logic diagram of the type mark counter, register and decoder used in the discriminating circuit shown in FIG. 2;
FIG. 6 is a timing diagram illustrating the operation of the logic circuitry shown in FIGS. 4 and 5;
FIGS. 7(a)-7(c) are plan views of alternate type belts which may be used in the practice of the invention with slight modification of the first embodiment;
FIGS. 8(a)-8(d) are plan views of type belts of 48, 64, 96 and 128 characters, respectively, according to a second embodiment of the invention;
FIG. 9 is a block diagram of the discriminating circuit according to the second embodiment;
FIG. 10 is a timing diagram illustrating the operation of the discriminating circuit shown in FIG. 9;
FIG. 11 is a logic diagram of the mark recognizing circuit used in the discriminating circuit shown in FIG. 9;
FIG. 12 is a logic diagram of the discrimination mark counter, register, decoder and hold pulse generator used in the discriminating circuit shown in FIG. 9;
FIGS. 13(a) and 13(b) are plan views of type belts of higher and lower pitch, respectively, which may be discriminated according to another aspect of the invention;
FIG. 14 is a block diagram of the discriminating circuit according to the first embodiment modified to discriminate between higher and lower pitch type belts; and
FIG. 15 is a timing diagram illustrating the operation of the discriminating circuit shown in FIG. 14.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1(a)-1(d) show various type belts. The type belts 1 shown in these figures have 48 different characters, 64 different characters, 96 different characters and 128 different characters, respectively. Type marks 3 are provided below types 2 on each type belt 1, respectively. The aforementioned synchronizing mark 4 is provided between the type marks 3 and on the same line of the type marks, and, furthermore, a discrimination mark 5 is also provided between the type marks 3 and on the same line of the type marks. The discrimination mark 5 is to determine the kind of a type belt 1. More specifically, the discrimination mark 5 is provided between the first and second type marks 3 from the synchronizing mark in the case of the type belt 1 having 48 different characters; it is provided between the second and third type marks 3 from the synchronizing mark 4 in the case of the type belt 1 having 64 different characters; it is provided between the third and fourth type marks 3 from the synchronizing mark 4 in the case of the type belt 1 having 96 different characters; and it is provided between the fourth and fifth type marks 3 from the synchronizing mark 4 in the case of the type belt 1 having 128 different characters. Thus, if the position of the discrimination mark 5 is detected by counting the number of type marks from the synchronizing mark 4, the kind of the type belt 1 can be discriminated.
FIG. 2 is a block diagram illustrating one concrete example of a device for carrying out such discrimination. The type marks 3, the synchronizing mark 4 and the discrimination mark 5 are disposed on one and the same line. Therefore, even though they are detected by a mark detector, they cannot be distinguished from one another. Accordingly, the detection signals of the mark detector are recognized and classified into a type mark signal, a synchronizing mark signal and a discrimination mark signal by a mark recognizing circuit 11. The mark signals are classified by the mark recognizing circuit 11 by first recognizing the relative spacing and hence timing between type marks 3 and synchronizing and discrimination marks 4 and 5, and second recognizing the sequence or order of appearance of marks 4 and 5. This will be described in more detail with reference to FIG. 4 hereinbelow. The mark signals thus classified by the mark recognizing circuit 11 are supplied to counter 12 and register 13. The synchronizing mark signal clears a type mark counter 12, while the type mark signal is counted in the type mark counter 12. That is, the type mark counter 12 counts the number of type marks 3 detected by the mark detector after detection of a synchronizing mark 4. When the discrimination mark 5 is detected, the contents of the two lower significant bits of the output of the type mark counter 12 are stored in a register 13. The output of the register 13 is applied to a decoder 14 which provides one of four outputs indicating the kind of the type belt 1 descriminated. The output of the decoder 14 becomes effective after a discrimination finish signal is provided. This is to prevent an erroneous output when a correct discrimination operation is not carried out. The generation of the discrimination finish signal will also be described with reference to FIG. 4.
FIG. 3 is a timing diagram representing the case of a type belt 1 having 64 different characters. After the synchronizing mark signal, the type mark signal occurs twice, and, therefore, the output of the type mark counter 12 is "2". If, in this case, the discrimination mark signal is provided, the two lower significant bits ("10" in binary notation) are stored in the register 13. The output of the register 13 is decoded by the decoder 14. When the discrimination finish signal indicating the finish of discrimination of the kind of a type belt is applied at the timing of the trailing edge of the discrimination mark signal, the output signal of the decoder becomes effective, as a result of which a signal line provided for the type belt having 64 characters become effective. In the case of the belt with 48 characters, the contents stored in the register 13 are "0 1"; in the case of the belt with 128 characters, the contents are "0 0". These make the signal lines of 48 characters, 96 characters and 128 characters effective to discriminate the respective type belts.
FIGS. 4 and 5 are logic circuits illustrating a concrete example of the block diagram shown in FIG. 2. More specifically, FIG. 4 shows the mark recognizing circuit 11, while FIG. 5 shows the type mark counter 12, the register 13 and decoder 14. FIG. 6 is a timing diagram for a description of the operation of the logic circuit shown in FIG. 4. The belt drive signal shown in FIG. 6 has a logical value "1" which drives an electric motor (not shown) adapted to drive the type belt 1. The discrimination permit signal is a signal having a logical value "1" which is provided a predetermined period of time after the generation of the belt drive signal or after the travelling speed of the type belt 1 reaches a predetermined value, and it is required to correctly carry out mark signal recognition (described later); that is, the discrimination permit signal prevents the mark signal recognition before the type belt 1 reaches its predetermined speed. The 16-character (CHAR) signal is a signal having a logical value "0" which is provided through an inverter 117 (FIG. 5) when the type mark counter 12 counts 16 type mark signals. The mark detector 101 (FIG. 4) is a magnetic pickup such as that disclosed in U.S. Pat. No. 3,785,545. Therefore, whenever the above-described type mark 3 or synchronizing mark 4 or discrimination mark 5 on the type belt 1 is detected by the mark detector 101, a detection mark signal is outputted by an amplifier 102 connected to the mark detector 101.
The time constant T 2 of a monostable multivibrator 108 is so selected that it is larger than the time constant T 1 of a monostable multivibrator 107 but smaller than the period of the type mark signal obtained when the type belt 1 is successively rotatably moved at the predetermined speed. Accordingly, the detection mark signal provided during the period of time during which an AND gate 109 is open (the monostable multivibrator 107 is restored to be in a steady state, but the monostable multivibrator 108 is not restored to be in a steady state yet) passes through an AND gate 106, and it is determined as the synchronizing mark signal or the discrimination mark signal. On the other hand, the detection mark signal provided during the period of time during which the AND gate 109 is closed, passes through a negative logic AND gate 105, and it is regarded as the type mark signal. The first detection mark signal passing through the AND gate 106 is determined as the synchronizing mark signal by means of a flip-flop 112 and an AND gate 114. This detection mark signal is applied through an inverter 110 to the clock input terminal of the flip-flop 112 to change the state of the latter. If, after a detection mark signal has passed through the AND gate 106 but before the type mark counter 12 counts 16 type mark signals, there is a detection mark signal which passes through the AND gate 106, this detection mark signal is recognized as the discrimination mark signal with the aid of the flip-flop 112 and the AND gate 115. Upon detection of this discrimination mark signal, it is applied through an inverter 116 to a flip-flop 113, as a result of which the state of the flip-flop 113 is inverted by the trailing edge of the discrimination mark signal, and, therefore, the discrimination finish signal is produced. If there is no detection mark signal passing through the AND gate 106 during the time interval which elapses from the detection of the first detection mark signal which passed through the AND gate 106 until the type mark counter 12 counts 16 type mark signals, the discrimination mark signal is not produced, and, therefore, the discrimination is not finished. Accordingly, the flip-flop 112 is reset through negative logic NOR gate 111 by the aforementioned 16-character signal, and, therefore the detection mark signal which passes through the AND gate 106 next is regarded as the synchronizing mark signal again.
In other words, if, after a detection mark signal passes through the AND gate 106 but before the type mark counter 12 counts 16 type mark signals, a detection mark signal passes through the AND gate 106, then the former detection mark signal is determined as the synchronizing mark signal, and the latter detection mark signal is determined as the discrimination mark signal. In contrast, if no detection mark signal passes through the AND gate 106 before the type mark counter 12 counts 16 type mark signals, no discrimination mark signal is produced, and, therefore, the discrimination is not finished. Upon detection of the discrimination mark signal, it is applied to the clock input terminals of flip-flops 118 and 119 forming the register 13 shown in FIG. 5, as a result of which the information of the two lower significant bits of the type mark counter 12--that is, "0 1" in the case of 48 characters, or "1 0" in the case of 64 characters, and so forth--is stored in the flip-flops 118 and 119. Upon receipt of the discrimination finish signal, AND gate 120-123 forming the decoder 14 are enabled. That is, in the case of the type belt having 48 characters, the gate 120 is opened, thereby indicating that the type belt has 48 characters; in the case of the type belt having 64 characters, the AND gate 121 is opened, thereby indicating that the type belt has 64 characters, and so forth.
In the embodiment described above, the type belt 1 has the type marks 3, the synchronizing mark 4 and the discrimination mark 5 arranged on one line; however, these marks may be arranged as follows. As shown in FIGS. 7(a)-7(c), the synchronizing mark 4 and the discrimination mark 5 are provided on different lines, respectively, or they may be arranged on one line, with the type marks on another line. However, if the marks 3, 4 and 5 are arranged on one end and the same line as described before, detection of the marks can be achieved by only one mark detector, which contributes to simplification of the mechanical arrangement of the device.
FIGS. 8(a)-8(d) show another example of the type belt to which the discrimination system according to this invention is applied. In this case, a discrimination mark 6 serves not only as a discrimination mark but also as a synchronizing mark. The discrimination mark 6 and the type marks 3 are provided on one and the same line. FIGS. 8(a)-8(d) show type belts 1 having 48 different characters, 64 different characters, 96 different characters and 128 different characters, respectively. As is apparent from FIGS. 8(a)-8(d), one discrimination mark 6 is provided on the type belt with 48 characters; two discrimination marks 6 on the type belt with 64 characters; three discrimination marks 6 on the type belt with 96 characters; and four discrimination marks on the type belt with 128 characters. Therefore, the kind of the type belt can be discriminated by counting the number of discrimination marks 6.
FIG. 9 is a block diagram illustrating one example of a device adapted to carry out such discrimination. Detection mark signals obtained by detecting the type mark 3 and the discrimination mark or marks 6 are classified into a type mark signal and a discrimination mark signal by means of a mark recognizing circuit 21. Upon detection of the type mark signal, a discrimination mark counter 25 is cleared while a hold pulse generator 26 is operated. After a type mark signal is detected, the hold pulse generator 26 outputs a pulse adapted to store the contents of the discrimination mark counter 25 in a register 23 during a period of time longer than a period of time for generating all the discrimination mark signals but before the provision of the following type mark signal. This pulse is generated only when the contents of the discrimination mark counter 25 are not "0". The output of the register 23 is applied to a decoder 24, where the kind of the type belt is determined. The output of the decoder 24 is not made effective before discrimination of the kind of the type belt is finished-- that is, it becomes effective when the discrimination finish signal is provided. This is again to prevent an erroneous character set discrimination signal from being produced.
FIG. 10 is a timing diagram representing the case of a type belt 1 having 64 different characters. When the first discrimination mark signal is provided after the generation of the type mark signal, a value "1" is added in the discrimination mark counter 25 which has been cleared by the type mark signal, and, therefore, the output thereof is "0 0 1" in binary notation. The discrimination mark signal clears the contents of the type mark counter 22. When the second discrimination mark signal occurs, a value "1" is added to the count value of the discrimination mark counter 25, and, therefore, the output thereof becomes "0 1 0" in binary notation. Thereafter, when the hold pulse is outputted by the hold pulse generator 26, the contents of the discrimination mark counter 25 are stored in the register 23. The output of the register 23 is decoded, and when the discrimination finish signal is available, the signal line specifying the type belt having 64 characters is activated. Data stored in the register 23 in the case of the type belt having 48 characters are "0 0 1", while data stored in the register 23 in the case of the type belt having 96 characters are "0 1 1". Furthermore, in the case of type belt having 128 characters, data stored in the register 23 and "1 0 0". These data activate the signal lines specifying the type belts having 48, 96 and 128 characters, respectively.
FIGS. 11 and 12 are logic diagrams concretely illustrating the circuitry shown in the block diagram of FIG. 9. More specifically, FIG. 11 shows the above-described mark recognizing circuit 21, and FIG. 12 shows the discrimination mark counter 25, the hold pulse generator 26 and the decoder 24. In FIGS. 11 and 12, those components which have been previously described with reference to FIGS. 4 and 5 have, therefore, been similarly numbered. As in the case of FIG. 4, the detection mark signal which passes through an AND gate 106 while an AND gate 109 is open is regarded as the discrimination mark signal, and it is allowed to pass through an AND gate 141 upon application of the above-described discrimination permit signal thereto. The discrimination mark signal is applied to the clock input terminal of the discrimination mark counter 25, which is cleared by the type mark signal, where it is counted. The hold pulse generator 26 comprises a monostable multivibrator 152 which is triggered by the type mark signal and has a time constant shorter than the period of the type mark signal obtained when the type belt 1 successively rotatably moves at a predetermined speed but longer than the period of time during which all the discrimination mark signals occurs. An OR gate 151 provides the logical sum of the output of the discrimination mark counter 25. An AND gate 153 provides the logical product of the output of the OR gate 151 and the "0" side output of the monostable multivibrator 152. A differentiation circuit 154 differentiates the output of the AND gate 153, and the differentiated output is inverted by inverter 155. The output of the hold pulse generator, or the output of the inverter 155, is the hold pulse. The hold pulse is applied to the load input terminal of the register 23 and to the clock input terminal of a flip-flop 156. Accordingly, upon provision of the hold pulse, the number of the discrimination mark signals, or the number of the discrimination marks 6, counted by the discrimination mark counter 25 (one for the type belt of 48 characters; two for the type belt of 64 characters; and so forth) is stored in the registor 23, while the state of the flip-flop 156 is changed, as a result of which the discrimination finish signal is generated. The decoder 24 comprises inverters 157 and 158 and AND gate 159-162 as shown in FIG. 12. Upon provision of the discrimination finish signal, one of the AND gates 159-162 is opened according to the number of discrimination marks 6, discriminating the kind of the type belt in question. More specifically, in the case of the type belt having 48 characters, an AND gate 159 is opened, in the case of the type belt having 64 characters, the AND gate 160 is opened, and so forth.
FIGS. 13(a)-13(b) show type belts 1 which are different in the distance between adjacent characters (hereinafter referred to as "type pitch"). More specifically, FIG. 13(a) shows a type belt 1 higher in type pitch, while FIG. 13(b) shows a type belt 1 lower in type pitch; however, both of the type belts 1 have 64 characters. On the type belt 1 higher in type pitch, a discrimination mark 7 is provided between the second type mark 3 and the third type mark 3 from the synchronizing mark 4. On the other hand, on the type belt 1 lower in type pitch, a discrimination mark 7 is provided between the tenth type mark 3 and the eleventh type mark 3 from the synchronizing mark.
FIG. 14 is a block diagram illustrating a concrete example of a device capable of discriminating the type pitch and the number of types simultaneously. Since the device shown in FIG. 14 is substantially similar to that in FIG. 2, the detailed description thereof will be omitted. When the discrimination mark 7 is detected, the output bits 2 0 , 2 1 and 2 3 of a type mark counter 32 are stored in a register 33--that is, the data "0 1 0" is stored therein in the case of the former type belt 1 higher in type pitch, the data "1 1 0" is stored therein in the case of the latter type belt 1 lower in type pitch. The two lower significant bits "1 0" of the data indicate that the type belt has 64 characters. If the most significant bit is "0", then the type belt 1 is higher in type pitch; and if it is "1", then the type belt 1 is lower in type pitch. With the type belt 1 lower in type pitch, when the discrimination mark 7 is detected, "6" is stored in the register 33 as indicated in FIG. 15. (Although the output of the type mark counter 32 is "1 0", "6" is provided because the bit 2 2 is disregarded. ) The output of the register 33 is applied to a decoder 34, whereby discrimination of the type pitch and the kind of the type belt is carried out. As a result, the signal line specifying the type belt having 64 characters is activated, while the signal line specifying the type pitch is also activated. This means that the type belt 1 is lower in type pitch and has 64 characters.
As is apparent, in this invention, it is not required to count all the type marks on the type belt. Accordingly, errors in discrimination can be minimized, and the time required for discrimination can be reduced. Furthermore, since the count value of the counter adapted to detect the position of the discrimination mark or the number of discrimination marks is small, the arrangement of the counter can be simplified. These are the significant merits of the invention.
|
Systems for discriminating among a plurality of type carriers differing in number of characters and pitch of characters are disclosed. In one circuit, the type carrier is provided with synchronizing marks and discrimination marks in addition to the usual type character marks. The synchronizing mark is located at the beginning of a set of characters, and the discrimination mark is located a predetermined distance from the synchronizing mark according to the number of characters and pitch of the particular type carrier. This distance is determined by counting type character marks. In another circuit, one or more discrimination marks are provided between type character marks at the beginning of a set of characters. The number of discrimination marks indicates the number of characters of the particular type carrier. In either circuit, a counter of only a few stages and a simple decoding circuit are all that are required to carry out the discrimination operation.
| 1
|
[0001] This application is a divisional of prior application Ser. No. 10/771,775, filed Feb. 2, 2004, currently pending;
[0002] Which is a divisional of prior application Ser. No. 09/681,598, filed May 4, 2001, now U.S. Pat. No. 6,697,982, issued Feb. 24, 2004.
COPYRIGHT STATEMENT
[0003] A portion of the disclosure of this patent document contains material which is subject to copyright or mask work protection. The copyright or mask work owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright or mask work rights whatsoever
BACKGROUND OF INVENTION
[0004] 1. Field of Invention
[0005] This invention relates to improvements in testing integrated circuits, in general, and to improvements in methods for testing embedded core integrated circuits while preserving the intellectual property contained in the core circuits, that is, protecting the core circuits from being discovered or determined by inspection of the testing software, in which virtual or pseudo pins are used to represent at least a portion of the core circuits to the testing software.
[0006] 2. Relevant Background
[0007] Recently, embedded integrated circuit cores have been increasingly popular. An embedded circuit core is an integrated circuit building block or module that is embedded into a system chip. Examples of such embedded cores include customizable digital signal processors (cDSPs), which may be embedded into a system that is integrated onto a single integrated circuit chip. The DSP may be of a proprietary design, and the peripheral and supporting circuitry may be customized for a particular use or customer.
[0008] Presently, some companies sell “embedded core” or circuit designs for use by customers who wish to design their own custom circuit content to produce their own customized or application specific integrated circuits (ASICs). As an example, a customer may wish to design its own peripheral circuits for use with a particular DSP core. In practice, the designer of the DSP provides a circuit description of the DSP in a format that will enable the customer to fabricate his desired circuit. The DSP description, however, will ideally be only sufficient to enable the customer to fabricate the custom DSP, together with peripheral circuits of its own design onto an integrated circuit, but does not disclose the specific design and circuitry of the embedded DSP. A chip in which the embedded core is included is sometimes referred to as a system on chip (SOC).
[0009] However, using this chip manufacturing technique gives rise to several problems. For example, from a business standpoint, to make the design of a core circuit economically feasible, the design often needs to be reusable in many diverse customer circuit designs. However, the delivery of a complete circuit design to a customer often enables the customer to reverse engineer the circuit, enabling the circuit configuration, and other aspects of the circuit, to be discovered. The customer then has the ability to reproduce the circuit at will, thereby shortening the lifetime during which the core designer can recoup its design and engineering costs. Therefore, unless steps are taken to protect against reverse engineering the core, the value of the intellectual property in the core may be compromised. Such embedded cores in which the owner has one or more intellectual property interests have recently been referred to as “IP cores”.
[0010] Therefore, when an embedded IP core is delivered to a customer, details of construction of the core are generally not disclosed. The information that is disclosed often is just sufficient to enable the user to interface its own circuitry to the IP core. Thus, previous IP core models often were treated as “black boxes”, in order to protect the IP content embodied in the models. No visibility into the internal structure or circuitry of the models was provided. Thus, for example, the core often may be delivered only as a circuit description, with only the connection pins and required signal parameters thereof being disclosed. However, this makes testing of the embedded core difficult or impossible. However, a properly designed core should be completely tested at least in a netlist version before being delivered to a customer for use with its custom designed circuitry. Thus, ideally, it should be unnecessary for the customer to repeat the core tests, except to the extent necessary to properly test the added circuitry and their interface and operation with the core.
[0011] Nevertheless, after an ASIC has been designed and manufactured, the chip should be tested for manufacturing defects. This typically involves first simulating a properly functioning ASIC, developing a variety of input test patterns and applying them to the simulated ASIC, and determining the expected outputs of the ASIC. The input test patterns are then applied to the actual ASIC. The actual outputs are then compared to the expected outputs. Deviations from the expected outputs indicate that the ASIC has a manufacturing defect.
[0012] Because of the complexity of the logic buried within the ASIC, an enormous number of test patterns may be required to properly test the integrated circuit device. One technique that has been used to test such integrated circuits is to add “scan cells” to the ASIC at strategic locations throughout the circuit. Scan cells are points at which logic values may be forced into the ASIC (scan writable gates) and/or observed within the ASIC (scan readable gates). Scan cells normally take the form of flip-flops which may be forced to desired logic values from outside the ASIC, or which may be read from outside the ASIC to determine particular behavior of the ASIC, for example after the test inputs have been applied. For instance, some scan cells enable an external tester to preset a counter within the ASIC to a particular count, and to capture values that verify that combinatorial logic derived from the counter outputs is working properly.
[0013] In general, in the design of such scan flip-flops, non-scan flip-flops are often converted into scan flip-flops by adding some additional logic gates, often including a multiplexer. The multiplexer selectively allows either the test values or the circuit values to be applied to the scan cell with which it is associated. The multiplexer is operated for example by a selection signal applied to a selected pin of the ASIC.
[0014] Strategic placement of scan cells within an ASIC allows the number of test patterns required to fully test an ASIC to be drastically reduced. Scan cells are normally connected in long chains, allowing all of the scan cells to be written or read from using only a few dedicated test I/O pins on the ASIC. This is important primarily because the computer simulations necessary to produce the test patterns and expected resulting outputs require a great deal of computer resources. Without scan cell techniques, simulation times to produce test patterns that adequately test an ASIC would be impractically long. Furthermore, without scan cells some gates within an ASIC may be simply not testable. However, using scan cells it is often possible to develop test patterns that will detect 99% or more of possible gate failures using a set of test patterns that is not impractically long. The fault coverage obtained is the percentage of possible gate failures that will be detected by a given set of test patterns.
[0015] Nevertheless, ASIC designs using embedded cores present a challenge to test. To assist the custom designers, embedded cores typically are supplied by the vendor along with a set of test patterns, which, if applied in isolation, will produce 99% fault coverage. However, these patterns cannot usually be applied to the embedded core in isolation, because the core is buried inside the ASIC with no direct access to the core's primary inputs and primary outputs. Hence, it is not possible to apply the supplied set of test patterns to the core in isolation unless some mechanism is supplied for accessing the core.
[0016] Among the isolation schemes that have been proposed are the use of multiplexed isolation, boundary scan cells wrapped around the core, and core parallel module testing, which includes the use of multiplexers to allow direct access to the circuitry in question. All of these proposed techniques result in area and performance overhead, which may make these techniques unacceptable for many applications.
[0017] A second possible type of approach is to generate new test vectors which will be applied at the ASIC level. Test pattern generation software is well known in the art, and is usually provided by third party vendors. Although it is possible for the ASIC vendor to generate a complete set of test vectors to test the customer's ASIC, many customers demand that third party vendors be capable of taking the customer's ASIC design and generating test vectors for it, without requiring any further assistance from the vendor.
[0018] The input to a test pattern generation program is typically a flattened ASIC netlist. A netlist is a list of circuit elements and their interconnections, and may be manually generated, or may be generated by known software programs for use in other software programs. Of course in a circuit as complex as a DSP, it would be impractical or impossible to manually generate a useful netlist.
[0019] The flattened netlist describes the complete ASIC in terms of primitives such as AND and OR gates, and their functional interconnections. The netlist is described as flattened because the cores, which are hierarchical functional blocks, have been reduced to their constituent primitives and interconnections. Using the flattened netlist, the test pattern generation software is able to generate test patterns that will test the ASIC with an extremely high percentage of fault coverage.
[0020] The problem with which a present invention is concerned is that of supplying a flattened netlist to the customer from which the third party's test pattern generator software can generate test patterns to test the entire ASIC, conflicts with the goal of keeping the detailed design of cores confidential. The flattened netlist for the core comprises much of the proprietary design details that the ASIC vendor desires to keep confidential.
[0021] Furthermore, in many circuit designs a large quantity of nonproprietary circuitry may be used. In DSP designs, for example, IEEE standard 1149.1 is often followed in the provision of testing circuitry, referred to as boundary scan or “JTAG” circuitry. To access the JTAG circuitry, a JTAG Interface circuit is provided, which also accesses the scan chains that are provided in the core. The modeling of the JTAG circuitry is non-trivial.
[0022] What is needed, therefore, is a method for enabling a core user to test the core, together with its own added circuitry, without compromising the intellectual property contained in the core, and in particular without unduly complicating the scan model due to the presence of required additional test circuitry, or the like.
SUMMARY OF INVENTION
[0023] In light of the above, therefore, it is an object of the invention to provide a method for enabling a core user to test the core, together with its own added circuitry, without compromising the intellectual property contained in the core.
[0024] Intellectual Property (IP) cores lend themselves to easy integration, but not to test. This poses several test challenges in core based/core dominated systems. The methods provided by the present invention allow for the proper use of insertion of test circuitry and automatic test pattern generation (ATPG) tools, when used in the context of core based, or core dominated, digital circuit designs. This leads to significant fault coverage improvements, while at the same time, maintaining protection of the proprietary IP core.
[0025] According to a broad aspect of the invention, a method is presented for enabling scan test vectors to be generated by an automatic test vector generating software program for a customer designed integrated circuit having an embedded vendor circuit. The embedded vendor circuit has a proprietary circuit and a nonproprietary circuit. The method includes creating at least one pseudo input to represent at least a portion of the nonproprietary circuit that is not necessary to be exercised by the automatic test vector generating software program to generate test vectors for the customer designed integrated circuit. An output node of the embedded vendor circuit to which an input of the customer designed circuit is connectable is identified. A test netlist is created which represents circuitry that produces output states at the output node which would be generated by the embedded vendor circuit thereat. The test netlist includes at least one pseudo input and the output node, without including a full netlist of either the proprietary or nonproprietary circuits. Thus, scan test vectors for the customer designed integrated circuit can be generated by the automatic test vector generating software program using the test netlist with the output node connected to an input of a netlist representing the customer supplied circuitry.
[0026] According to another broad aspect of the invention, a method is presented for generating test vectors to test an integrated circuit having an embedded vendor circuit and customer supplied circuitry. The embedded vendor circuit includes a proprietary circuit and a nonproprietary circuit. At least one pseudo input is created to represent at least a portion of the nonproprietary circuit that is not necessary to be exercised by an automatic test vector generating software program to generate test vectors at least for the customer supplied circuitry. An output node of the embedded vendor circuit to which an input of the customer supplied circuitry is connectable is defined. A test netlist is created which represents circuitry that produces output states at the output node which would be generated by the embedded vendor circuit thereat. The test netlist includes the at least one pseudo input and the output node, without including a full netlist of either the proprietary or nonproprietary circuits. A netlist of the customer supplied circuitry is combined with the test netlist to form a total netlist. And an automatic test vector generating software program is applied to the total netlist to generate test vectors therefor.
[0027] According to another broad aspect of the invention, a system is presented for generating a test netlist of an embedded vendor circuit which includes a proprietary circuit and a nonproprietary circuit for use by a customer in adding thereto customer supplied circuitry. The system includes means for creating a test netlist which represents circuitry having at least one pseudo input to represent at least a portion of the nonproprietary circuit that is not necessary to be exercised by an automatic test vector generating software program. When a netlist for the customer supplied circuitry is combined with the test netlist, scan test vectors at least for the customer supplied circuitry can be generated by an automatic test vector generating software program.
BRIEF DESCRIPTION OF DRAWINGS
[0028] The invention is illustrated in the accompanying drawings, in which:
[0029] FIG. 1 is a block diagram of a circuit illustrating one environment in which the invention may be practiced.
[0030] FIG. 2 is a block diagram of a circuit illustrating another environment in which the invention may be practiced.
[0031] And FIG. 3 is a flow chart illustrating the steps according to a preferred embodiment of the invention method for generating test vectors to test an integrated circuit having an embedded vendor circuit which includes a proprietary circuit and a nonproprietary circuit and which also includes customer supplied circuitry.
[0032] In the various figures of the drawing, like reference numerals are used to denote like or similar parts.
DETAILED DESCRIPTION
[0033] The method proposed by the present invention addresses the problem of testing integrated Intellectual Property (IP) cores through the proper use of insertion of test circuitry and automatic test pattern generation (ATPG) tools, when used in the context of core based, or core dominated, digital circuit designs. This leads to significant fault coverage improvements, while at the same time, maintaining protection of the proprietary IP core. One technique by which this may be achieved is as follows.
[0034] An internal scan chain only, partial netlist version of the embedded core in question is first extracted or developed, including only the key input and output logic cones associated with the scan flip-flops which are fed from primary inputs, and including the scan flip-flops which are driving primary output ports or pins of the core extracted. This applies as well to cores without any direct boundary scan implementations. This task may be wholly or partially performed using known software.
[0035] Next, the cells of the netlist are renamed using a generic notation, to eliminate any remnants of functionality to assist in further removing the possibility for reverse engineering of the specific contents of the embedded core.
[0036] Test pattern creation/generation is then performed, first by replacing the existing core with its partial netlist version equivalent (the scan only “model”) in the netlist hierarchy of the design. Additionally required top level input pins are introduced for proper scan mode control of the scan only model. The automatic test pattern generation (ATPG) software is then run, taking advantage of the core visibility available through the scan only model and the added test control it provides. The corresponding appropriate format test pattern files are then generated, and the test pattern files are edited to remove the additional scan only model inputs.
[0037] According to an alternative embodiment of the invention that is used exclusively with respect to ATPG a “Reset or Fixed State” only ATPG model of the embedded core is used. This technique is relatively similar to the above, except the focus is not so much IP protection, but rather the controllability of the embedded core output signal. This technique is particularly useful when support for the scan only model (partial netlist) extraction is not available for a particular embedded core.
[0038] According to the alternative embodiment, there is no extraction of any kind from the actual core netlist other than determining the state of the outputs of the embedded core at a know “Reset” or specific “Fixed” state; therefore, no IF issues are involved. However, the alternative technique provides a much less desired level of controllability than the “scan only model/partial netlist” approach. The alternative embodiment does, however, provide significant improvement over using just the embedded core in a “black box” context.
[0039] The alternative technique first determines the state of the outputs of the embedded core at a known “reset” or specific “fixed” state through simulation or some other available means, such as device specific documentation. From this information, an ATPG model representing this derived “fixed” state of the embedded core is constructed. Along with this model, just like in the “Scan Only Model” case, a corresponding ATPG setup sequence, using only the actual top level pins of the design, (i.e.: no pseudo pins needed) may be derived as well. The test pattern creation/generation is then performed by running the ATPG software on the overall embedded core based design using the newly derived ATPG model and test setup sequence. Generate corresponding appropriate format test pattern files are generated. Since, the design netlist is not changed the resulting pattern files are ready for use as is, without requiring post ATPG editing.
[0040] More particularly, FastScan.™. is one popular automatic test pattern generation (ATPG) program that is available from Mentor Graphics Corp, Wilsonville, Oreg., USA. Other programs are available as well. In operation, setup files are provided for the program, and the program automatically generates a set of test vectors that can be applied to test the circuit. The setup files contain a number of things needed for the program to run, which may include, for example, a list of initialization states that may be applied to the circuitry to produce known output results. This enables a circuit designer to append or attach his circuitry to the netlisted circuitry to accomplish his desired customized circuitry.
[0041] As described above, the netlist of the core circuitry may be a flattened or abbreviated netlist, so that the IP content of the core is not revealed to the user. However, as mentioned, much of the circuitry that will be included in the final circuit design is provided by the core vendor, but is not necessary for design verification/simulation by the custom circuit designer. An example of such additional circuitry is the JTAG Interface circuitry that may be provided with a DSP, or other similar product. Although the ATPG software may well develop appropriate test patterns for the JTAG circuitry, the test vectors are unnecessary, and, moreover, may be very complicated. As a result, and in accordance with a preferred embodiment of the invention, “pseudo-pins” are provided as a part of the setup files provided to the ATPG software.
[0042] Pseudo-pins have no circuitry associated with them, and, in fact, do not exist in the physical circuitry. They stand-in for actual circuitry pins for the ATPG software. More particularly, the pseudo-pins provide a placeholder to which the test patterns applied to the circuitry may be applied, but without the actual accompanying hardware circuitry, they do not result in the generation of a large number of test vectors by the software. Since no physical circuitry is represented by the pseudo-pins, no test vectors are generated, except those that generate the pre-established responses that may be provided in the set-up files. That is, the set-up files may contain the logic states to be applied to the pseudo-pins to produce the desired output states in the actual circuit operation. Thus, the pseudo-pins may be used to emulate the expected response by the core circuit, without including the possibly complex circuit netlist.
[0043] This is particularly useful in the case of an IP core; that is, a core that has content that is desired to be maintained in secrecy. When the set-up files are delivered to the user they may include only the initial state or setup sequences that emulate the nonproprietary circuitry that the pseudo pins replace. As a result, not only is the test vector generation greatly simplified, but the IP content of the core is maintained, as well.
[0044] Of course, once the ATPG software has generated the test vectors to test the actual physical circuitry that is represented by the netlist and other set-up files, the pseudo-pin references must be removed from the test vector files. Therefore, when the test vectors are applied to the actual circuitry in its test, the test vectors can be applied to the correct circuitry inputs. As mentioned, the test vectors for the vendor core circuitry ideally would have been already generated by the core vendor. As a result, the final combined circuitry test vectors may be somewhat redundant and unnecessary.
[0045] With reference first to FIG. 1 , a block diagram of a circuit 10 is shown illustrating one environment in which the invention may be practiced. The circuit 10 includes both vendor embedded circuitry 12 and customer designed circuitry 14 that are integrated onto a single integrated circuit chip 16 . In the embodiment illustrated, the vendor circuitry 12 is a digital signal processor (DSP); however, it should be understood that other circuitry may be equally advantageously employed.
[0046] The vendor embedded circuitry 12 includes both proprietary circuit portions 18 and nonproprietary circuit portions 20 , which are tested in known manner by signals applied via a chain of scan flip-flops 22 . The test signals normally are conducted to the chain of scan flip-flops 22 from a JTAG Interface circuit 24 , and, after traversing the scan chain 22 are returned through the JTAG circuitry via a multiplexer 26 for analysis. The JTAG Interface circuit 24 , for example, generates test signals according to IEEE standard 1149.1, and is shown for convenience as being included within the nonproprietary circuitry 20 . The embedded vendor circuitry 12 is intended to be used by the customer as the core around which the customer desires to design its own circuitry that can take advantage of the capabilities of the core circuitry. However, in order to enable the customer to design its circuitry, sufficient details of the embedded vendor core must be provided to the customer, as described above.
[0047] The customer designed circuitry 14 includes the core of customer circuitry 28 and a chain of scan flip-flops 30 . At least one output from the embedded vendor DSP 12 is applied as an input to the customer designed circuitry 14 , as denoted by the dotted line 31 . The customer circuitry 28 is tested by signals applied via the chain of scan flip-flops 30 , separately from the test signals applied to the embedded vendor circuitry 12 . The application of the test signals to the scan chain 30 of the customer circuitry 28 may also be sourced from the JTAG Interface circuit 24 and returned therethrough via the multiplexer 26 .
[0048] It should be noted, however, that typically the circuitry of the JTAG Interface circuit 24 is relatively complex, and is mostly, if not entirely, nonproprietary. Moreover, in some cases the JTAG Interface circuit 24 is mostly, if not entirely, used in the testing of the embedded vendor circuitry 12 , rather than the customer designed circuitry 14 . As a result, the inclusion of the circuitry of the JTAG Interface circuit 24 in the netlist that is provided to the customer to enable the customer to develop its circuitry may unduly complicate the design and test of the customer designed circuitry 14 , and specifically the ATPG software development of the test vectors for testing the customer circuitry 28 . For example, when the ATPG software is applied to the entire circuit including both the embedded vendor DSP and customer designed circuitry 14 , it must contend with the signal modifications made by the circuitry of the JTAG Interface 14 . This may add significant time to the generation of the test vectors for testing the final circuits.
[0049] Therefore, according to the invention, some or all of the circuitry of the vendor core may be represented by the “pseudo pins” described above in the netlist provided to the customer to enable the customer to use the ATPG software to generate its text vectors for the customer circuitry. For example, pseudo input or pseudo pin 25 is shown providing an input to the embedded vendor DSP 12 . Since the generation of the test vectors for the customer circuitry is not affected by the operation of the JTAG Interface circuitry, the pseudo pin approach greatly simplifies and shortens the test vector generation by the ATPG. An example of a test netlist that may be furnished to a customer is attached hereto as “Appendix A”. Also shown is a second pseudo input or pseudo pin 27 that may be used, if desired, to emulate other portions of the non-proprietary circuit 20 .
[0050] It should be noted that the supplied embedded vendor DSP core model and its accompanying JTAG interface circuitry in most cases have already been verified by the vendor at the time they are provided to the customer. Consequently, when the customer runs an ATPG program to generate the test vectors of its own circuitry, it may at least partially duplicate the testing of the previously verified embedded vendor DSP core.
[0051] After the ATPG test vectors have been generated, a removal program may be applied to the vendor supplied netlist to remove the references to the pseudo pins from the netlist. An example of such program is attached as “Appendix B”.
[0052] With reference additionally now to FIG. 2 , a block diagram of another circuit 35 is shown illustrating another environment in which the invention may be practiced. The circuit 35 includes both vendor embedded circuitry 36 and customer designed circuitry 38 that are integrated onto a single integrated circuit chip 40 . In the embodiment illustrated, the vendor circuitry 36 again is a digital signal processor (DSP); however, it should be understood that other circuitry may be equally advantageously employed.
[0053] The vendor embedded circuitry 36 includes both proprietary circuit portions 42 and nonproprietary circuit elements 44 , which are tested in known manner by signals applied via a chain of scan flip-flops 46 . The test signals are conducted to the chain of scan flip-flops 46 directly from a JTAG Interface circuit 48 . In some cases, the JTAG Interface circuit 48 , for example, generates test signals according to IEEE standard 1149.1. In the embodiment of circuitry 35 , it is clear that the JTAG Interface circuit 48 affects only the embedded vendor DSP 36 , and not the customer designed circuitry 38 .
[0054] The customer designed circuitry 38 includes circuitry 39 and 41 , which receive outputs 43 from the embedded vendor core circuitry 36 , and two or more chains of scan flip-flops 50 and 52 . At least one output from the embedded vendor DSP or core 36 is applied as an input to the customer designed circuitry 39 and 41 , as denoted by the dotted line 53 . The customer circuitry 38 is tested by signals applied via the chains of scan flip-flops 50 and 52 , separately from the test signals applied to the embedded vendor circuitry 36 ; however, it is noted that some of the inputs to the scan flip-flops 50 are derived from outputs from the embedded vendor DSP 36 .
[0055] In the embodiment of FIG. 2 , at least some of the functions of the JTAG Interface circuit 48 are emulated or replaced by one or more pseudo-pins 47 , as shown. Also, if desired, other portions of the nonproprietary circuitry 44 may be emulated or replaced by pseudo-pins 49 , as shown. Since the functions of the JTAG Interface circuit 48 and optionally other functions of the nonproprietary circuit 44 are emulated or replaced by the use of the pseudo pins 47 and 49 in combination with the setup states in the set up files, the pseudo-pins and setup files may be used to enable the customer to utilize the ATPG software tools to test the customer circuitry in the chip. Thus, the pseudo pin approach greatly simplifies and shortens the test vector generation by the use of such ATPG tool.
[0056] Again, after the ATPG test vectors have been generated, a removal program may be applied to the netlist to remove the references to the pseudo pins. An example of such program is attached as “Appendix B”.
[0057] Thus, in accordance with a preferred embodiment of the invention, a method is presented for testing a circuit having both an embedded circuit core and appended user circuitry, using ATPG software to generate test vectors therefor. The steps of the method are illustrated in FIG. 3 , to which reference is now made. The steps are broken up into two phases, the first performed by the vendor, the second performed by the customer. The process begins with the vendor steps, in which the vendor first generates a partial netlist of the entire embedded vendor core 60 . At least one pseudo pin input is defined for at least some of the circuitry in the partial netlist 62 . Also, an output node of the vendor circuit to which the customer circuitry will be connected is identified 64 .
[0058] Thus, it can be seen that according to one aspect of the invention, pseudo-pin inputs may be substituted into the core netlist for at least some of the circuitry, for example the JTAG Interface circuitry of FIGS. 1 and 2 . With this substitution, an abbreviated core netlist of the vendor circuit that includes the pseudo pins and the output node is generated 66 . The abbreviated netlist is then delivered to the customer to enable the customer to develop and append its own custom circuit to the embedded vendor circuit.
[0059] During the second phase of circuit development, the customer develops its own circuit 68 in the form of a customer netlist. The customer netlist is appended or attached to said abbreviated core netlist with substituted pseudo-pins to produce an abbreviated total circuit 70 . The ATPG software is then applied to the abbreviated total circuit to produce a number of circuit test vectors 72 . Thereafter, references to the pseudo-pin inputs are removed from the total circuit 74 and the removed original circuitry is substituted back thereinto 76 . Finally, the test vectors are applied to the original circuitry.
[0060] Although the invention has been described and illustrated with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example, and that numerous changes in the combination and arrangement of parts can be resorted to by those skilled in the art without departing from the spirit and scope of the invention, as hereinafter claimed.
|
A method generates test vectors for a customer designed integrated circuit having an embedded vendor circuit. The embedded vendor circuit has a proprietary circuit and a nonproprietary circuit. At least one pseudo input is defined to represent a portion of the nonproprietary circuit to emulate the nonproprietary circuit output. An output node of the embedded vendor circuit to which an input of the customer designed circuit is connectable is identified. A test netlist is created which represents circuitry that produces output states at the output node which would be generated by the embedded vendor circuit thereat. The test netlist includes at least one pseudo input and the output node, without including a full netlist of either the proprietary or nonproprietary circuits, and can be used to generate scan test vectors for the customer designed integrated circuit by the automatic test vector generating software program.
| 6
|
The present application is a division of application Ser. No. 661,958, filed on Feb. 27, 1976, now U.S. Pat. No. 4,031,606, and which is a division of application Ser. No. 552,284, filed Feb. 24, 1975, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to ion concentration measuring apparatus. More specifically, the present invention is directed to a solid state ion responsive electrode and reference electrode.
2. Description of the Prior Art
Conventional ion concentration measuring electrode structures have usually used a glass measuring electrode, a reference electrode and a thermal compensator. For example, various types of special glasses have been used to measure the pH of aqueous solutions. In making these glass electrodes the pH sensitive glass is usually fused to the end of a less expensive glass tube and is subsequently blown into a small bulb of about two to four mils thick. These "hand-blown" pH glass electrodes are fragile, have very high electrical impedance due to the thickness of the glass and are used for limited temperature ranges mainly because of the internal pressure developed by a liquid electrolyte fill which is subsequently introduced into the interior of the pH measuring electrode to provide an electrically conductive ion source. An example of a typical prior art pH electrode apparatus is shown in U.S. Pat. No. 3,405,048 of D. J. Soltz. These prior art glass electrodes are expensive mainly because of the extensive use of highly skilled manual labor in the construction of the glass envelope and the subsequent filling thereof. A somewhat similar construction is used in the construction of the prior art reference cell which additionally increases the cost of the overall conventional pH measuring system. Despite its disadvantages, the glass electrode has retained its popularity in the field of ion concentration measurement even after attempts to develop a solid state electrode such as that shown in U.S. Pat. No. 3,498,901 of L. T. Metz et al since the response of the glass electrode is faster than other prior art devices with the glass electrode also having the broadest useful pH range. However, in order to provide a low cost and even more useful ion concentration measuring system it is desirable to produce a low impedance, high reliability and relatively unbreakable ion concentration measuring electrode and reference electrode.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an improved solid state ion responsive and reference electrode structure.
Another object of the present invention is to provide a method for making a reference electrode structure.
In accomplishing these and other objects, there has been provided, in accordance with the present invention, method for making a combination ion responsive and reference electrode structure having an insulating substrate supporting an electrically conductive structure overlaid with a solid electrolyte layer having a final thin layer of ion responsive glass being attached to the solid electrolyte layer by RF sputtering. In the reference electrode, the outer glass layer has a coefficient of thermal expansion different from the solid electrolyte layer while in the ion responsive electrode, the outer ion responsive glass layer is substantially thermally matched to the supporting electrolyte layer.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention may be had when the following detailed description is read in connection with the accompanying drawings, in which:
FIG. 1 is a pictorial illustration of a cross-section of a reference electrode embodying the present invention,
FIG. 2 is a pictorial illustration of a cross-section of a an ion concentration measuring electrode embodying the present invention, and
FIG. 3 is a pictorial illustration of a cross-section of a combination ion responsive, reference electrode and thermal compensator embodying the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 in more detail, there is shown a pictorial illustration of a cross-section of a reference electrode embodying the present invention. An electrically insulating substrate 2 of an electrically insulating material, e.g., ceramic or glass, has a first layer 4 of chromium (Cr) deposited on one side thereof. A second layer 6 of silver (Ag) is subsequently deposited on the chromium and a third layer 8 of silver chloride (AgCl) is deposited on the silver. An outer layer 10 of a suitable glass is RF sputtered on the exposed surface of the silver chloride layer 8. The glass material for the outer layer 10 is selected to have a coefficient of thermal expansion different from the supporting silver chloride structure 8 whereby a subsequent temperature cycling of the multilayer structure is effective to produce microscopic cracks in the outer glass layer. For example, borosilicate glass has a coefficient approximately 1/10 that of silver chloride. These cracks provide ion conduction paths to the silver chloride layer from an aqueous solution in which the reference electrode is immersed during pH measurements. A socket shell 12 is arranged to enclose a single contact pin 14. The contact pin is electrically connected by an electrically conducting wire 16 to the silver layer 6 of the multilayer structure. An encapsulating, or potting, compound 18 is subsequently applied to the multi-layer structure, the socket shell 12, the contact pin 14 and the connecting wire 16 to form a moisture-proof barrier and to unite the elements into a rigid package. An open window, or hole, 19 is formed through the potting compound 18 to expose the outer glass layer 10.
In FIG. 2, there is shown a pictorial illustration of an exemplary cross-section of a pH measuring electrode embodying the present invention. Similar reference numbers have been used in FIGS. 1 and 2 to indicate similar structural elements although the combination of FIG. 2 is directed toward a different device from that shown in FIG. 1. An electrically insulating substrate 2, e.g., glass or ceramic, is used as a support member for a multi-layer structure similar to that used in the reference electrode. Specifically, the glass substrate 2 is first plated with a first layer 4 of chromium which is followed by a second layer 6 of silver and a subsequent third layer 8 of silver chloride. An outer layer 20 of pH sensitive glass is then RF sputtered on the silver chloride layer. The temperature coefficient of the silver chloride and pH glass layer are matched whereby the pH glass will not produce microscopic cracks as during normal temperature cycling, e.g., 0° to 100° C, as in the case of outer glass layer used in the reference electrode previously described. For example, Corning 1990 glass has a coefficient of thermal expansion approximately one-half that of silver chloride. Other pH sensitive glasses can be produced to even more closely match the coefficient of thermal expansion of the silver chloride layer by using glass formulas with the following characteristics: a high coefficient of expansion can be achieved by using oxides such Li 2 O, Na 2 O, K 2 O, Rb 2 O, Cs 2 O, BaO and SrO while a low coefficient of expansion can be achieved by using SiO 2 , B 2 O 3 , Al 2 O 3 , BeO and TiO 2 . Thus, the coefficient of thermal expansion of the silver chloride layer or other solid state electrolyte materials such as CuO, AgI, RbI, RbAg 4 I 5 , etc. can be matched to an even closer approximation if either the temperature cycling during the measurement operation or the electrolyte material layer imposes a need for such a match. The thickness of the pH glass is approximately 10 to 10,000 A. A thermal compensator structure may be produced using an insulating substrate with a thermal sensitive element mounted therein and having the same overall configuration as that used for the aforesaid reference and pH electrodes whereby the three elements would be used concurrently as shown in the aforesaid Soltz U.S. Pat. No. 3,405,048.
In order to further utilize the solid state nature of the electrodes of the present invention, a combination structure having the reference electrode, the ion concentration measuring electrode and the thermal compensator integrated therein is shown in FIG. 3. As in the case of FIGS. 1 and 2, similar reference numbers have been reused in FIG. 3 for common, or similar, elements of the structure but a capital "A" reference letter has been added to some repeated reference numbers to indicate similar elements in adjacent sections of the integrated cell structure shown in FIG. 3. Thus, in the case of a pH electrode, a first substrate 2 of an electrically insulating material has the first chromium layer 4 followed by the silver layer 6 and the silver chloride layer 8 with an outer layer of the selected mismatched temperature coefficient glass 10 to form the reference electrode portion of the integrated cell. A second electrically insulating substrate 2A has a chromium layer 4A followed by a silver layer 6A and a silver chloride layer 8A with a pH glass outer layer 20. A socket shell 24 which may advantageously be a larger size than the socket shell 12 shown in FIGS. 1 and 2 to accommodate an additional number of connector pins is provided adjacent to one side of the aforesaid multilayer structure.
A plurality of electrical connector pins 26, 28, 30 and 32 are located within the connector shell 24. A first one of the pins 26 is connected to the silver layer 6A in the pH measuring electrode section of the integrated multilayer structure by wire 16A. Similarly, the fourth pin 32 is connected by a wire 16 to the silver layer 6 in the reference electrode portion of the integrated multilayer structure. The second and third pins 28 and 30 are connected to a thermal compensator element 34 by separate wires 36 and 38 whereby the thermal compensator element 34 is electrically connected across the second and third pins 28 and 30. The thermal compensator element 34 may be formed in a recess of the second substrate element 2A by any suitable means which can include the same RF sputtering technique used to provide the layers of the pH and reference electrodes structures. Finally, an outer shell, or convering, of a potting compound 40 is provided to enclose the multilayer structure and to secure the pins 26 to 32 while engaging the connector shell 24. A first hole, or window, 19 is provided in the covering 40 to expose the glass layer 10 of the reference electrode while a second opening 19A is provided in the covering 40 to expose the pH glass layer 20 of the pH electrode structure.
MODE OF OPERATION
Since, in the RF sputtering process operation, the operating temperatures are below 200° C, the preparation of the ion responsive electrode structure including the ion responsive glass layer is performed over a much smaller temperature range which further prevents the ion responsive glass from cracking when it is cooled down to room temperature even if the ion responsive glass layer and electrolyte layer do not have an exact temperature coefficient match. Additionally, the thin, i.e., 10,000 A maximum, glass layer will stretch instead of cracking during temperature cycling to enable the overall multilayer structure to withstand temperature cycling over a relatively wide temperature range, e.g., -70° C to +200° C. Inherently, the integrated electrode structure has a low impedance due to the thinness of the outer glass layer. Another feature is an extreme ease of replacement whereby the pH electrode, the reference electrode and the thermal compensator can be replaced as a single inexpensive unit. Further, since the delicate glass handling operations required for prior art electrodes have been eliminated, the high manufacturing repeatability of the produce and the reduction of manufacturing rejects enhances the low manufacturing costs of either the separate electrodes shown in FIGS. 1 and 2 or the combinational electrode structure shown in FIG. 3. Finally, in addition to savings in the amounts of materials used for the thin layers of the multilayer structure, additional savings will be effected by the elimination of certain expensive metals which were necessary in previous glass electrodes because of the required glass-to-metal seals, e.g., platinum or other similar thermal property metals.
Accordingly, it may be seen that there has been provided, in accordance with the present invention, a solid state ion responsive and reference electrode structure and method having application in either a separate or a combination electrode construction.
|
A solid state pH measuring electrode having the pH measuring electrode structure formed by successive layers on an insulating substrate with an outer pH sensitive glass layer being deposited on a supporting solid electrolyte layer by RF sputtering. The reference electrode is similarly formed by depositing an outer layer of glass onto a supporting solid electrolyte layer by RF sputtering with the temperature expansion of the glass and supporting solid electrolyte structure being selected to produce a differential expansion causing random cracking of the glass layer during temperature cycling of the reference electrode. A combination structure is provided wherein the pH measuring electrode and the reference electrode are formed on opposite sides of the same electrically insulating substrate with a thermal compensating element being included in the integrated package.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application No. 61/671,646, entitled “Enhanced Adserving Metric Determination” and filed Jul. 13, 2012, which is hereby incorporated in its entirety as if it were fully set forth herein.
[0002] This application is related to U.S. Pat. No. 7,904,520, granted Mar. 8, 2011, entitled “First Party Advertisement Serving,” which is incorporated herein by reference for all purposes.
TECHNICAL FIELD
[0003] Implementations described herein relate generally to systems, methods, and processes for counting the unique viewers of internet ads. For example, implementations relate to determining whether a single user has been exposed and/or interacted with an ad one or more times from a single or multiple devices (work computer, home computer, tablet, smartphone, etc.) and/or multiple locations (work, home, other). Additionally, reports can be generated that demonstrate how many of the customers of that advertiser don't accept or regularly delete cookies.
BACKGROUND
[0004] Advertising via the Internet continues to grow and evolve at a rapid pace. Internet browser technology has evolved to encompass security and privacy concerns as well as new device extensions. Internet advertising counting methodologies have generally relied on internet cookies to track the users to determine how many times they have been exposed to ads. More specifically, the counting methodologies have generally relied on third-party internet cookie tracking because the vast majority of tracking companies utilize cookies within their own domain to serve internet ads and track the performance. In many cases, information from an advertiser site domain is transferred to the ad server site domain via the third-party cookies to be used for ad targeting purposes. Internet users are becoming increasingly aware of the data transfer and object to the transfer without their knowledge and permission. For example, if you visit www(dot)Domain1(dot)com you will get various third-party cookies set by the Domain1.com advertising and tracking partners as well as many Domain1.com first-party cookies set by their site partners and internal systems. In response, browser makers have enhanced access to cookie controls to enable the user to: 1) block all cookies; 2) block third-party cookies; 3) allow all cookies. Some mobile browsers are set by default to block third-party cookies and only allow first-party cookies. Standard internet advertising practices use third-party cookies to count internet ad exposure as well as the reach and frequency of those exposures. A problem encountered in counting ad views using third-party cookies is that third-party cookies can be blocked or deleted by the browser, secondary programs or users themselves. When the third-party cookies are blocked or deleted, the reach and frequency counting accuracy can be significantly over/understated, respectively. Interestingly, first-party cookie counting is less susceptible to automated cookie blocking and deletion than third-party cookie counting because users are more comfortable with cookies from companies they know and trust. Additionally, automated cookie deletion programs such as anti-spyware programs are focused on known tracking companies and generally leave first-party cookies alone.
[0005] The proliferation of digital devices and the emergence of new First-Party only browsers set a trend that limits the effectiveness of traditional third-party measurement techniques and the vendors in the eco-system that rely on them because they have no control over the upstream systems. Studies have consistently shown a rising trend in measurement deficiency—now greater than three times over traditional reach and frequency. The same factors that impact the measurement techniques are also impacting performance measurement—the association of responses to display advertising at similar rates.
SUMMARY
[0006] Due to enhanced privacy concerns, newer internet browsers and anti-spyware products are making it easier for users to control the acceptance and deletion of internet cookies on their browsers. For example, internet browsers can be set to:
[0007] 1) accept all cookies;
[0008] 2) reject third-party cookies but accept first-party cookies;
[0009] 3) reject all cookies.
[0010] Internet advertisers use reach to determine how many users have seen their ads for Return on Investment (ROI) calculations.
[0011] Reach calculations for third-party cookies as described by the Interactive Advertising Bureau (IAB) Audience Reach Measurement Guidelines Version 1 Dec. 8, 2008, which is incorporated by reference herein in its entirety, are becoming more and more unreliable due to the volatility of third-party internet cookies due to the issues described herein.
[0012] First-Party cookies can get rejected or deleted by the browser but are less likely to get deleted because they are associated with a specific advertiser rather than an unknown company or third-parry ad server.
[0013] In one implementation, a process to provide reach and/or frequency calculations is provided. In one particular implementation, for example, a multiple-step process successively refines a reach calculation by adding:
[0014] 1) A User ID;
[0015] 2) An alternate user ID to the log file and;
[0016] 2) A user registration ID from an advertiser registration system.
[0017] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other features, details, utilities, and advantages of the claimed subject matter will be apparent from the following more particular written Detailed Description of various implementations and implementations as further illustrated in the accompanying drawings and defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 illustrates an example ad serving operating environment.
[0019] FIG. 2 , collectively including each of sub- FIGS. 2A through 2C , is a flow chart of scenarios of browser security settings.
[0020] FIG. 3 is a comparison of first-party ad server setup (domain) to third-party ad server setup (domain).
[0021] FIG. 4 , collectively including each of sub- FIGS. 4A through 4D , has example reports with the data collected and potential charts depicting the path analysis of a user on different devices and across different locations.
[0022] FIG. 5 illustrates a general purpose computing system in which various operations described herein may execute.
[0023] FIG. 6 illustrates example operations used for determining one or more metrics related to advertisement serving.
[0024] FIG. 7 shows an example implementation of an ad serving environment in which a plurality of identifiers are used in targeting an advertisement to be provided to a user.
[0025] FIG. 8 shows another example implementation of an ad serving environment in which a browser and/or device fingerprint identifier is used in targeting an advertisement to be provided to a user.
[0026] FIG. 9 shows another example implementation of an ad serving environment in which a pixel firing measurement is performed.
DETAILED DESCRIPTION
[0027] U.S. Pat. No. 7,904,520 entitled “First Party Advertisement Serving” issued Mar. 8, 2011 to Neal et al. describes various first-party advertisement serving techniques and is incorporated by reference herein in its entirety. As described herein, these techniques can be useful in improved measurement of advertisement serving, such as determinations of advertisement reach and frequency. Ad counts based on cookies set in the first-party domain of the advertiser, for example, can be used in determining various measurements related to advertisement serving.
[0028] While in many instances, a First-Party measurement system may be much less likely as impacted by cookie blockings or deletions as third-party measurement systems, a measurement model is provided that, in one implementation, comprehends systematically a normalized measurement capability as the measurement landscape becomes increasingly challenging.
[0029] In some implementations, a model that comprehends one or more factors that impact measurement accuracy and provides advertisers one or more robust and empirical ways to understand performance of their advertising, make effective attribution and media investment decisions is provided. In one implementation, for example, a production validation methodology provides normalized measurement across the following response dimensions:
[0030] Reach & Frequency
[0031] Media Overlap
[0032] Device Overlap
[0033] Closed Loop Measurement and Response Attribution
[0034] Generally accepted counting practices (Interactive Advertising Bureau (IAB), MMA) use a new/old cookie technique to track users for reach and frequency counting. In this technique, if no cookie is present, a new cookie is set and the impression and reach are counted, but the technique does not look for a previous impression to link for multi-impression tracking. If a cookie is present, however, the cookie's status is changed to old and then the impression and the reach is counted. The technique also looks back in the log files for a previous ad exposure for multi-impression counting. This technique enables an ad serving company to track ad exposure and frequency to a specific browser to allow for strategic ad rotation as well as Return on Investment (ROI) calculations by a publisher site. If cookies are blocked or deleted by any one of the above mentioned processes, the reach numbers will be much higher because new cookies look like unique users and frequency numbers will be understated because it appears that ads are displayed to multiple users not just one. For example, one person that has their browser set to reject cookies seeing the same ad twice in two different internet surfing sessions will be counted as being two people (reach) seeing the add one time each (frequency) whereas they should be counted as one person with a frequency of two.
[0035] In one implementation, the flawed standard new/old cookie setting and reach calculation process is supplemented by including the addition of:
[0036] 1) Identification numbers added to log files of a first-party cookie;
[0037] 2) ID values set by secondary advertiser site based systems to count ads more accurately in the following scenarios:
A) Users with a browser set to block or delete cookies or anti-spyware software that does the same; B) Users on different devices (computer, tablet, smart phone); C) Users at different locations.
DEFINITIONS
[0041] The following identification values are merely examples of values that may be used within one or more systems or processes described herein.
[0042] A user identifier (e.g., User_ID) is a standard cookie with an ID set on a browser by an ad server. In one implementation, for example, the user identifier (User_ID) comprises a combination of a server number and a sequence ID generated by an algorithm in each server.
[0043] An alternate user identifier (e.g., Alt_User_ID) is provided to a client device (e.g., by TCP/IP communications in conjunction with HTTP headers) and is created in one or more log files (e.g., from an IP address and a user agent string (e.g., operating system, browser brand and version)). In one implementation, for example, the alternate user identifier may include a device and/or browser “fingerprint” that includes information that can be used to identify a device and/or browser in use on the device. Non-limiting information that may be used to assemble a “fingerprint” for the device and/or browser, for example, may include information such as a user agent (including browser type (e.g., Internet Explorer, Chrome, Apple Safari, Firefox, etc., version, operating system), plug in(s) present, fonts, screen resolution, color depth (e.g., 16, 32 bit, etc.), computer settings, Internet Protocol address, MAC address, or other information that can be obtained or derived from the device and/or browser.
[0044] A registration identifier (e.g., Registration_ID) is set by one or more site-side systems as a first-party cookie and is read/writeable by the other systems in the First-Party domain space. In one implementation, for example, a Customer Management System (CMS) leverages user registration information to create a cookie with a unique customer identifier.
Scenarios (FIG. 1 )
[0045] FIG. 1 shows an example ad serving operating environment. In this environment, one or more devices 100 , such as but not limited to the work computer, home computer, tablet and smart phone devices shown, connect to various web sites on a network (e.g., the Internet) via a browser 150 operating on the one or more devices 100 . The devices 100 , for example, may connect to a publisher web site 200 , an ad server web site 250 and/or an advertiser web site 300 via the browser 150 .
[0046] Where a user is a registered user of the advertiser website, for example, the browser may provide registration information data to the advertiser web 300 site to establish credentials when accessing the advertiser web site 300 . The registration information data may be used, for example to log in or otherwise inform the web site of the identity of the user and/or establish credentials with the web site.
[0047] As described above, the browser 150 may be set at various privacy settings, such as accept all cookies, reject third party cookies but accept first party cookies or reject all cookies.
[0048] In one scenario a user has their browser set to accept all cookies ( 101 ) and the user already has a User_ID ( 102 ). An Alt_User_ID is then created in a log file ( 103 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 105 ); 2) Alt_User_ID reach and frequency reports ( 106 ); 3) User Device reports ( 107 ); 4) user cookie deletion reports ( 108 ). A subsequent check is made for a Registration_ID ( 109 ). If one is found, the Registration_ID is added to the log file ( 110 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 113 ); 2) User Device Reports ( 114 ); 3) User Location reports ( 115 ); 4) user cookie deletion reports ( 116 ).
[0049] In another scenario a user has their browser set to accept all cookies and the user already has a User_ID ( 102 ). The Alt_User_ID is then created in the log file ( 103 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 105 ); 2) Alt_User_ID reach and frequency reports ( 106 ); 3) User Device reports ( 107 ); 4) User cookie deletion reports ( 108 ). A subsequent check is made for the Registration_ID ( 109 ). If one is not found, nothing happens ( 117 ) unless the user visits the advertiser site ( 111 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 112 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 113 ); 2) User Device Reports ( 114 ); 3) User Location reports ( 115 ); 4) user cookie deletion reports ( 116 ).
[0050] In another scenario a user has their browser set to accept all cookies and the user does not have a User_ID ( 102 ). The User_ID cookie is set and the Alt_User_ID is then created in the log file ( 104 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 105 ); 2) Alt_User_ID reach and frequency reports ( 106 ); 3) User Device reports ( 107 ); 4) Cookie Deletion report ( 108 ). A subsequent check is made for the Registration_ID ( 109 ). If one is found, the Registration_ID is added to the log file ( 110 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 113 ); 2) User Device Reports ( 114 ); 3) User Location reports ( 115 ); 4) user cookie deletion reports ( 116 ).
[0051] In another scenario a user has their browser set to accept all cookies and the user does not have a User_ID. The User_ID cookie is set and the Alt_User_ID is then created in the log file and the following reports are generated: 1) User_ID reach and frequency reports; 2) Alt_User_ID reach and frequency reports; 3) User Device reports. A subsequent check is made for the Registration_ID ( 109 ). If one is not found, nothing happens unless the user visits the advertiser site ( 111 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 112 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 113 ); 2) User Device Reports ( 114 ); 3) User Location reports ( 115 ); 4) user cookie deletion reports ( 116 ).
[0052] In another scenario user has their browser set to reject third-party cookies ( 101 ). If the User_ID exists ( 202 ), the Alt_User_ID is created in the log file ( 203 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 205 ); 2) Alt_User_ID reach and frequency reports ( 206 ); 3) User Device reports ( 207 ); 4) Cookie Deletion reports ( 208 ). A subsequent check is made for the Registration_ID ( 209 ). If one is found, the Registration_ID is added to the log file ( 210 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 213 ); 2) User Device Reports ( 214 ); 3) User Location reports ( 215 ); 4) user cookie deletion reports ( 216 ).
[0053] In another scenario user has their browser set to reject third-party cookies ( 101 ). If the User_ID exists ( 202 ), the Alt_User_ID is created in the log file ( 203 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 205 ); 2) Alt_User_ID reach and frequency reports ( 206 ); 3) User Device reports ( 207 ); 4) Cookie Deletion reports ( 208 ). A subsequent check is made for the Registration_ID ( 209 ). If one is not found nothing happens ( 217 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 212 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 213 ); 2) User Device Reports ( 214 ); 3) User Location reports ( 215 ); 4) user cookie deletion reports ( 216 ).
[0054] In another scenario user has their browser set to reject third-party cookies ( 101 ). If the User_ID does not exist ( 202 ), the Alt_User_ID is created in the log file ( 204 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 205 ); 2) Alt_User_ID reach and frequency reports ( 206 ); 3) User Device reports ( 207 ); 4) Cookie Deletion reports ( 208 ). A subsequent check is made for the Registration_ID ( 209 ). If one is found, the Registration_ID is added to the log file ( 210 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 213 ); 2) User Device Reports ( 214 ); 3) User Location reports ( 215 ); 4) user cookie deletion reports ( 216 ).
[0055] In another scenario a user has their browser set to reject third-party cookies ( 101 ). If the User_ID does not exist ( 202 ), the Alt_User_ID is created in the log file ( 204 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 205 ); 2) Alt_User_ID reach and frequency reports ( 206 ); 3) User Device reports ( 207 ) 4) Cookie Deletion reports ( 208 ). A subsequent check is made for the Registration_ID ( 209 ). If one is not found, nothing happens unless the user visits the advertiser site ( 211 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 212 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 213 ); 2) User Device Reports ( 214 ); 3) User Location reports ( 215 ); 4) user cookie deletion reports ( 216 ).
[0056] In another scenario user has their browser set to reject all cookies ( 101 ). If the User_ID exists ( 302 ), the Alt_User_ID is created in the log file ( 303 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 305 ); 2) Alt_User_ID reach and frequency reports ( 306 ); 3) User Device reports ( 307 ); 4) Cookie Deletion reports ( 308 ). A subsequent check is made for the Registration_ID ( 309 ). If one is found, the Registration_ID is added to the log file ( 310 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 313 ); 2) User Device Reports ( 314 ); 3) User Location reports ( 315 ); 4) user cookie deletion reports ( 316 ).
[0057] In another scenario user has their browser set to reject all cookies ( 101 ). If the User_ID exists ( 302 ), the Alt_User_ID is created in the log file ( 303 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 305 ); 2) Alt_User_ID reach and frequency reports ( 306 ); 3) User Device reports ( 307 ); 4) Cookie Deletion reports ( 308 ). A subsequent check is made for the Registration_ID ( 309 ). If one is not found nothing happens ( 317 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 312 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 313 ); 2) User Device Reports ( 314 ); 3) User Location reports ( 315 ); 4) user cookie deletion reports ( 316 ).
[0058] In another scenario user has their browser set to reject all cookies ( 101 ). If the User_ID does not exist ( 302 ), the Alt_User_ID is created in the log file ( 304 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 305 ); 2) Alt_User_ID reach and frequency reports ( 306 ); 3) User Device reports ( 307 ); 4) Cookie Deletion reports ( 308 ). A subsequent check is made for the Registration_ID ( 309 ). If one is found, the Registration_ID is added to the log file ( 310 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 313 ); 2) User Device Reports ( 314 ); 3) User Location reports ( 315 ); 4) user cookie deletion reports ( 316 ).
[0059] In another scenario a user has their browser set to reject all cookies ( 101 ). If the User_ID does not exist ( 302 ), the Alt_User_ID is created in the log file ( 304 ) and the following reports are generated: 1) User_ID reach and frequency reports ( 305 ); 2) Alt_User_ID reach and frequency reports ( 306 ); 3) User Device reports ( 307 ) 4) Cookie Deletion reports ( 308 ). A subsequent check is made for the Registration_ID ( 309 ). If one is not found, nothing happens unless the user visits the advertiser site ( 311 ) and gets an Registration_ID in which case the Registration_ID is added to the log file ( 312 ) and the following reports are generated: 1) Registration_ID reach and frequency reports ( 313 ); 2) User Device Reports ( 314 ); 3) User Location reports ( 315 ); 4) user cookie deletion reports ( 316 ).
[0060] FIG. 3 provides a comparison of a first-party ad serving system to a third-party ad serving system. A distinction between first party and third party systems is that a first-party ad server ( 550 ) acts on behalf of the advertiser ( 600 ) and can read and write cookies in the advertiser domain (Domain1.com) or sub-domain (ad.Domain1.com). In the third-party ad serving model the third-party ad server ( 850 ) sets cookies in their own domain (Domain3.com) and does not work on behalf of the advertiser ( 900 ). Third-party cookie ad servers are targeted by many anti-spyware programs for deletion and are susceptible third-party cookie blocking and rejection in browsers.
[0061] The methods described herein facilitate the workflows of the individual players as well as the workflows between and among the advertiser and/or agency, e.g., TPAS, and the publishers. A campaign reporting system includes users surfing the web, ads served to their browsers, cookies accepted, rejected or deleted by/from their browsers, a database that logs files with the associated user cookie and ad information and a reporting system that uses cookies to track users and report on the reach and frequency of those ads.
[0062] Within the user's browser there are privacy controls that enable the user to Reject all cookies, reject only third-party cookies, and/or accept all cookies. There are also anti-spam and spyware programs that identify third-party data collection cookies and schedule them for deletion.
[0063] Internet Ads are typically controlled by cookies placed on the browser and enable the ad serving company to control which ads are viewed by the user. Internet browsers continue to evolve and new devices continue to be introduced that can take advantage of internet access. Cookie-type functionality is also evolving into files and databases as evidenced, but not limited to, the growing popularity of companies using Adobe Flash™ Local Shared Objects and Microsoft Silverlight™ “Isolated Storage” capabilities. Generally accepted advertising principals like frequency of ad exposure can be applied through these technologies to ensure that the user isn't exposed to the same ad too often thus reducing the possibility of ad burn-out.
[0064] On the reporting side, the process of the ad being served captures the unique cookie ID along with other user system data (IP Address, Browser Type, etc.) and the ad information (ad name, campaign, site, width/height, site section, etc.). The log files are processed to generate reports to show how many ads were served and then the reach of those ads (unique users) and frequency of those ads to the users as well as the actions by the users (click through, purchase, etc.). Cookies can be used to control the reach and frequency of the ads to help optimize the mix and increase the ROI of the campaign. If cookies are rejected or deleted it makes the reach and frequency reporting less accurate because many new cookies are served and subsequently counted as first impressions and unique users. Third-party cookies tend to get rejected and/or deleted more often than first-party cookies. First-party cookie technology, however, can be used to produce more accurate reach and frequency reports and can extend the process to include additional attributes to make the process even more accurate.
[0065] An exemplary implementation ( FIG. 3 ) may be understood in the context of a user visiting a website like Domain1.com that has a first-party advertising relationship with a first-party ad server. The first-party relationship enables the first-party ad server to read and write cookies in the first-party mode (ad.Domain1.com) to take advantage of relationship data that the advertising company may store in their cookies (ad.domain1.com=high_value) to serve relevant ads on their behalf. When the user visits the Domain1.com website and logs-in they receive a Domain1.com registration cookie (i.e. Domain1.com=RegID=1234). When the user then surfs the web and lands on a site where the first-party ad server is serving ads on behalf of Domain1.com, the first-party ad-server will receive the contents of the Domain1.com cookie jar and can take advantage of any data stored in the cookie on behalf of Domain1.com. In this scenario, the campaign served from the first-party ad-server may serve a specific ad to the user knowing that they are a registered high-value registered user of the advertiser site. If the user is concerned about online privacy they may have their browser set to:
[0066] 1) reject all cookies;
[0067] 2) reject only third-party cookies;
[0068] 3) accept all cookies.
Reject All Cookies
[0069] If the user rejects all cookies they will get sent a new cookie request every time from first-party the ad-server (ad.domain1.com) or Domain1.com and the first-party ad server log files will capture a new User_ID each time but construct the same Alt_User_ID as long as the user is logging in from a consistent IP Address and Browser. In this case it's possible to track that this user is returning and the ad server or advertiser could actually generate a report on user location, operating system and browser type and the amount of users that are not accepting or are regularly deleting cookies.
Reject Only Third-Party Cookies
[0070] If the user rejects third-party cookies but accepts first-party cookies there are a few scenarios: 1) when the user visits the Domain1.com website the user will receive a first-party cookie. 2) When the user visits a different domain site the user will be viewed as a third-party and will be able to read the first-party Domain cookie (Ad.domain1.com) but any cookie writing will be rejected. The log files will capture a “new” cookie when the cookie is set on the first-party domain and continue to count accurately for each third-party ad serve on the external domain. If the external domain is the first time the user is seen, the Domain1.com cookie will not be set because it will be viewed as a third-party cookie to the external domain. This difference can be significant because if the cookies are set in the first-party domain (ad.Domain1.com) they can be read in the third-party domain ( 200 ) even if the browser is set to not accept third-party cookies. The log files will also be updated with new->old cookies and reach will be counted correctly in this scenario, making the first-party ad serving process more accurate for reporting and optimization purposes.
Accept All Cookies
[0071] If the user accepts all cookies then the third-party ad serving and counting process and the first-party ad serving and counting process will be similar but there could be counting discrepancies when the user accesses the web from different locations or devices. For example, a user may login from work ( 110 ) and then surf the web and view ads and then go home, login and view ads on a separate computer ( 120 ), tablet ( 130 ), or smartphone ( 140 ). In this scenario the standard reach and frequency counting process would count a reach of 2 and a frequency of one even though the same ad was viewed on both systems and should be counted as a reach of one and frequency of two.
[0072] In various implementations, however, a first-party system using the Alt_User_ID would see different User_ID's and different Alt_User_ID's but the same Registration_ID and could link the user across locations (IP addresses) and systems (work computer, home computer, tablet or smartphone). In this scenario, an enhanced counting process could correctly count the reach and frequency while standard third-party counting techniques could be significantly different.
[0073] In various first-party implementations, a new reach and frequency counting process works in a first-party cookie mode and captures multiple data points to help counting accuracy whether the user has their browser set to accept or reject cookies, there is a cookie deletion action by a the user or an anti-spam/spyware system or they use different forms of access such as work computer, home computer, tablet and smartphone.
Exemplary Operations
[0074] FIG. 1 depicts an example ad serving environment. In this implementation, an advertisement serving system works on behalf of an advertiser and generates ad tags that are then placed by a publisher advertising system into purchased media inventory. When a user surfs with their browser ( 150 ) to a web page, the web page can have many calls to different servers for content. When the ad tag is requested, the browser sends a request to the advertisement server ( 250 ) along with a number of headers. These headers help the browser and the hosting server determine the best way to provide the requested information. The user agent string is included in one of the headers provided from the browser. The user agent string from Microsoft Internet Explorer 9, by default, provides the following information to the server:
1) Application name and version (“Mozilla/5.0”) 2) Compatibility flag (“Compatible”) 3) Version Tokens (“MSIE 9.0”) 4) Platform Tokens (Windows NT 6.1″) 5) Trident Token (“Trident/5.0”) (User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0).
In many browsers it is possible to change the user agent string but the user needs to be technically proficient or run a program to make the changes. In general, the vast majority of users don't know these use agent strings exist and will never change them. In a typical web surfing process a user will visit a webpage from one of their systems (work computer ( 110 ), home computer ( 120 ), tablet ( 130 ), smartphone ( 140 ), etc.) ( 100 ), a Publisher website ( 200 ) will send HTTP headers that may include ad tags which will direct the browser to send its HTTP header information to the Advertisement deployment server ( 250 ) and request an ad. Since the ad tag had the “Host: media.Domain1.com”, the browser will send along the user agent and any cookies in the cookie jar for Domain1.com which can be used for counting, reach and frequency calculations.
[0080] FIG. 6 shows example operations of a process 600 for determining data related to advertisement serving operations. The process 600 , for example, may be performed to determine statistics such as, but not limited to, impression frequency, reach, site overlap, path analysis and the like. In the implementation shown in FIG. 6 , for example, the process generates source data logs in operation 602 . The source data logs, for example, may include all or a subset of transaction data collected in an advertisement serving process, such as for a campaign or within a particular domain. The transaction data, for example, comprises all or a subset of impressions, clicks, and pings. The data may further include name value pairs from the raw data. The source data logs can then be loaded into an analysis system, such as into staging tables, in operation 604 . In one particular implementation, for example, the data is organized into sets for analysis. The sets, for example, may be organized around one or more advertising campaigns (e.g., by a campaign ID), an advertisement serving domain, such as for first party advertisement serving, (e.g., by a domain ID), around a start date, an end date and/or a date range, or by any other set organization useful for analysis.
[0081] The analysis system analyzes the source data logs (e.g., from the staging tables) in a variety of manners. In operation 606 , for example, the analysis system performs the data analysis against a cookie, such as described above with respect to the standard new/old cookie paradigm. In operation 608 , the analysis system performs data analysis against alternate user ID data (e.g., data that can be used to identify a user by browser or client device as described above). In operation 610 , the analysis system performs data analysis against registration identification information (e.g., a Registration ID) that is readable and/or writeable in the first party domain space within a first party advertisement scheme.
[0082] The results of operation 606 are then compared to the results of operations 608 and/or 610 to create a normalized data set in operation 612 . The normalized data set, for example, can be used to identify instances in which cookies (or other persistent browser information) may have been blocked or deleted. The normalized data, thus, provides improved measurement over standard new/old cookie analysis schemes.
[0083] It is important to note that either operation 608 or operation 610 may be performed in isolation or both operations 608 and 610 may be performed and the results compared to the results of operation 606 . Thus, the results of a standard cookie analysis (operation 606 ) may be compared to an analysis performed using alternate user information (operation 608 ) and/or an analysis performed using registration identification information (operation 610 ).
[0084] FIG. 7 shows an example implementation of an ad serving environment in which a plurality of identifiers are used in targeting an advertisement to be provided to a user. For example, the ad serving environment may use two or more of the user identifier, the alternate user identifier and the registration user identifier described herein as well as any number of other identifiers, including derivatives of those or other identifiers. In the example shown in FIG. 7 , for example, one or more devices 100 A, such as but not limited to the work computer, home computer, tablet and smart phone devices shown, connect to various web sites on a network (e.g., the Internet) via a browser 150 A operating on the one or more devices 100 A. The devices 100 A, for example, may connect to a publisher web site 200 A, an ad server web site 250 A and/or an advertiser web site via the browser 150 A.
[0085] In this particular example, a rendering engine executing on rendering server 450 A provides a placeholder tag in the browser 150 A of one or more of the devices 100 A. First party information (cookie or other data elements), if present at the device 100 A (e.g., in browser 150 A), are identified and provided to an ad server 400 A. The ad server 400 A accesses memory cache server 250 A (or other data storage device such as a database, disc storage or the like) to match one or more elements of the first party information and a unique (or semi-unique) browser fingerprint detail.
[0086] The memory cache server 250 A and/or the ad server 400 A identify and/or selects two or more identifiers, such as a user identifier, an alternate user identifier (e.g., a browser fingerprint) and/or a registration information identifier, to use to identify one or more advertisements from an advertiser database 300 A or other external data provider data sets 350 A to provide to the ad server 400 A for targeting engine/creative selection decisioning as well as measurement counting accuracy. The ad server 400 A determines whether to provide any additional or replacement identifiers and/or first party data elements back to the browser 150 A to be used for relatively more relevant and/or accurate targeting information for targeting and creative selection to serve advertisements.
[0087] FIG. 8 shows another example implementation of an ad serving environment in which a browser and/or device fingerprint identifier is used in targeting an advertisement to be provided to a user. As described herein, the fingerprint identifier may be used alone or with one or more other identifiers. In the example shown in FIG. 8 , for example, one or more devices 100 B, such as but not limited to the work computer, home computer, tablet and smart phone devices shown, connect to various web sites on a network (e.g., the Internet) via a browser 150 B operating on the one or more devices 100 B. The devices 100 B, for example, may connect to a publisher web site 200 B, an ad server web site 250 BA and/or an advertiser web site via the browser 150 B.
[0088] In this particular example, a rendering engine executing on rendering server provides a placeholder tag in the browser 150 B of one or more of the devices 100 B as described above with respect to FIG. 7 . Browser and/or device fingerprint elements are used to create a unique (or semi-unique) fingerprint key (e.g., a universal key) for the browser 150 B and/or device 100 B. The fingerprint key, for example, may be stored in the browser 150 B or the elements may be provided to an ad/meta data server 250 B, which can use the elements to create on or more keys for use in an ad serving process. The fingerprint key may be a universally unique key or sufficiently distinct to statistically sufficiently distinguish a wide sampling of devices and/or browsers for the purpose of serving ads.
[0089] In addition to the fingerprint key or fingerprint elements, first party data elements (e.g., cookie or other data), if present, may be forward to the ad/meta data server 250 B as well. The ad/meta data server 250 B selects universal key or fingerprint key records for targeting from an advertiser database 300 B or from any other third party data provider 350 B. New targeting information (e.g., based on fingerprint selections) is provided back to the ad server 250 B for targeting and creative selection to serve an advertisement as well as for measurement determination. As described above with respect to FIG. 7 , the ad server 250 B may also determine whether to provide any additional information such as identifiers and/or first party data elements back to the browser 150 B to be used for relatively more relevant and/or accurate targeting information for targeting and creative selection to serve advertisements.
[0090] FIG. 9 shows another example implementation of an ad serving environment in which a pixel firing measurement is performed. In the example shown in FIG. 9 , for example, one or more devices 100 C, such as but not limited to the work computer, home computer, tablet and smart phone devices shown, connect to various web sites on a network (e.g., the Internet) via a browser 150 C operating on the one or more devices 100 C. The devices 100 C, for example, may connect to a publisher web site 200 C, an ad server web site and/or an advertiser web site via the browser 150 C.
[0091] In this particular example, a rendering engine executing on rendering server 450 C provides a placeholder tag in the browser 150 C of one or more of the devices 100 C. First party information (cookie or other data elements), if present at the device 100 C (e.g., in browser 150 C), are identified and provided to an ad server 400 C. Browser and/or device fingerprint elements are also identified and provided to the ad server 400 C. The ad server 400 C accesses memory cache server 250 C (or other data storage device such as a database, disc storage or the like) to match one or more elements of the first party information and a unique (or semi-unique) browser fingerprint detail. As described above, the fingerprint key or detail may be a universally unique key or sufficiently distinct to statistically sufficiently distinguish a wide sampling of devices and/or browsers for the purpose of serving ads.
[0092] The memory cache server 250 C and/or the ad server 400 C identify and/or select one or more identifiers, such as a user identifier, an alternate user identifier (e.g., a browser fingerprint) and/or a registration information identifier, to use to identify one or more advertisements from an advertiser database 300 C or other external data provider data sets 350 C to provide to the ad server 400 C for pixel management and measurement details. For example, memory cache server 300 C can identify appropriate pixel(s) to fire on a browser 150 C (either advertiser, publisher, or other) to ensure accurate counting and measurement via using an appropriate primary key set and closing a loop. The ad server 400 C receives decisioning pixel identifiers to send back to the browser 150 C one or more instructions to fire one or more determined measurement pixel(s).
Exemplary Computing System
[0093] FIG. 5 is a schematic diagram of a computing device 1000 upon which a creatives management or deployment system may be implemented. As discussed herein, implementations include various steps. A variety of these steps may be performed by hardware components or may be embodied in machine-executable instructions, which may be used to cause a general-purpose or special-purpose processor programmed with the instructions to perform the steps. Alternatively, the steps may be performed by a combination of hardware, software, and/or firmware.
[0094] FIG. 5 illustrates an exemplary system useful in implementations of the described technology. A general purpose computer system 1000 is capable of executing a computer program product to execute a computer process. Data and program files may be input to the computer system 1000 , which reads the files and executes the programs therein. Some of the elements of a general purpose computer system 1000 are shown in FIG. 5 wherein a processor 1002 is shown having an input/output (I/O) section 1004 , a Central Processing Unit (CPU) 1006 , and a memory section 1008 . There may be one or more processors 1002 , such that the processor 1002 of the computer system 1000 comprises a single central-processing unit 1006 , or a plurality of processing units, commonly referred to as a parallel processing environment. The computer system 1000 may be a conventional computer, a distributed computer, or any other type of computer. The described technology is optionally implemented in software devices loaded in memory 1008 , stored on a configured DVD/CD-ROM 1010 or storage unit 1012 , and/or communicated via a wired or wireless network link 1014 on a carrier signal, thereby transforming the computer system 1000 in FIG. 5 into a special purpose machine for implementing the described operations.
[0095] The I/O section 1004 is connected to one or more user-interface devices (e.g., a keyboard 1016 and a display unit 1018 ), a disk storage unit 1012 , and a disk drive unit 1020 . Generally, in contemporary systems, the disk drive unit 1020 is a DVD/CD-ROM drive unit capable of reading the DVD/CD-ROM medium 1010 , which typically contains programs and data 1022 . Computer program products containing mechanisms to effectuate the systems and methods in accordance with the described technology may reside in the memory section 1008 , on a disk storage unit 1012 , or on the DVD/CD-ROM medium 1010 of such a system 1000 . Alternatively, a disk drive unit 1020 may be replaced or supplemented by a floppy drive unit, a tape drive unit, or other storage medium drive unit. The network adapter 1024 is capable of connecting the computer system to a network via the network link 1014 , through which the computer system can receive instructions and data embodied in a carrier wave. Examples of such systems include SPARC systems offered by Sun Microsystems, Inc., personal computers offered by Dell Corporation and by other manufacturers of Intel-compatible personal computers, PowerPC-based computing systems, ARM-based computing systems and other systems running a UNIX-based or other operating system. It should be understood that computing systems may also embody devices such as Personal Digital Assistants (PDAs), mobile phones, gaming consoles, set top boxes, etc.
[0096] When used in a LAN-networking environment, the computer system 1000 is connected (by wired connection or wirelessly) to a local network through the network interface or adapter 1024 , which is one type of communications device. When used in a WAN-networking environment, the computer system 1000 typically includes a modem, a network adapter, or any other type of communications device for establishing communications over the wide area network. In a networked environment, program modules depicted relative to the computer system 1000 or portions thereof, may be stored in a remote memory storage device. It is appreciated that the network connections shown are exemplary and other means of and communications devices for establishing a communications link between the computers may be used.
[0097] In accordance with an implementation, software instructions and data directed toward operating the subsystems may reside on the disk storage unit 1012 , disk drive unit 1020 or other storage medium units coupled to the computer system. Said software instructions may also be executed by CPU 1006 .
[0098] The implementations described herein are implemented as logical steps in one or more computer systems. The logical operations are implemented (1) as a sequence of processor-implemented steps executing in one or more computer systems and (2) as interconnected machine or circuit modules within one or more computer systems. The implementation is a matter of choice, dependent on the performance requirements of a particular computer system. Accordingly, the logical operations making up the embodiments and/or implementations described herein are referred to variously as operations, steps, objects, or modules. Furthermore, it should be understood that logical operations may be performed in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.
[0099] The implementations described herein are implemented as logical steps in one or more computer systems. The logical operations are implemented (1) as a sequence of processor-implemented steps executing in one or more computer systems and (2) as interconnected machine or circuit modules within one or more computer systems. The implementation is a matter of choice, dependent on the performance requirements of the computer system being used. Accordingly, the logical operations making up the implementations described herein are referred to variously as operations, steps, objects, or modules. Furthermore, it should be understood that logical operations may be performed in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.
[0100] The above specification, examples and data provide a complete description of the structure and use of exemplary implementations of the invention. Since many implementations of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. Furthermore, structural features of the different implementations may be combined in yet another implementation without departing from the recited claims.
[0101] In some implementations, articles of manufacture are provided as computer program products. One implementation of a computer program product provides a transitory or non-transitory computer program storage medium readable by a computer system and encoding a computer program. Another implementation of a computer program product may be provided in a computer data signal embodied in a carrier wave by a computing system and encoding the computer program.
[0102] Furthermore, certain operations in the methods described above must naturally precede others for the described method to function as described. However, the described methods are not limited to the order of operations described if such order sequence does not alter the functionality of the method. That is, it is recognized that some operations may be performed before or after other operations without departing from the scope and spirit of the claims.
|
A user can view creative from multiple locations (same laptop) and multiple devices (work computer, home computer, tablet, smartphone). The user can also adjust their privacy settings on their browser to accept or reject cookies and/or have anti-spam/spyware software that regularly deletes cookies. An enhanced counting method uses first-party cookie technology to track users across access channels and across privacy settings on their browser. The non-acceptance and deletion of cookies causes the accuracy of the traditional third-party cookie calculated reach and frequency calculations to vary widely. First-party cookies reduce this variability but are still subject to non-acceptance or deletion so additional actions need to be taken to provide the opportunity for accurate reports. Additional steps to increase the accuracy of reach and frequency reporting are provided.
| 6
|
This is a National Phase Application filed under 35 U.S.C. 371 as a national stage of PCT/DK2009/000207, filed 18 Sep. 2009, and claiming the benefit from Danish Application No. BA 2009 00049, filed Mar. 7, 2009, the content of which is hereby incorporated by reference in its entirety.
BACKGROUND
1. Field
The present disclosure relates to a coffin, which in its design, function and in its choice of material is environmentally-friendly.
2. Background
Hitherto it is known to have coffin, where there is shown a two spited coffin, with an outer an inner coffin, but first after that one has dismounted one or more vertical placed holding—or distance plugs between the two coffins. An example is represented by Danish Utility Model DK 2000 00282.
The disadvantage is that the configuration uses wood, which in this version is expensive, and that it only very difficult over time for it to disintegrate by putrefaction, which very well could last half to a whole year. Additionally, subsequent to burial, it becomes necessary to add additional earth, because the earth sinks as a result of crushing of the coffin.
The disadvantage is, unless one uses an inner coffin and a outer coffin (vault), and even when using the two coffins, then collapse of the lid by displacement into the coffin can be difficult, and the coffin will not be able to immediately be shaped into a compact form and be drawn down tight over the body.
With the invention one want to make an arrangement of coffin, of the mentioned sort, where one for the first can establish or make an arrangement of coffin, which is essential cheaper than earlier, in the same time with that this by this will be more environmentally friendly, and where it by its design has such a function, that one generally can avoid causing the earth on the place of burial to sink after some time following the funeral.
SUMMARY
A coffin is configured with a lid which, upon backfilling with earth is able to be displaced or collapse into the coffin, and down against the body, as a result of the lid having, in its edges, folding arrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing, in a sectional view, a coffin, which permit the lid to collapse over the decedent upon backfilling of the grave with earth.
FIG. 2 is a diagram showing, in a sectional view, and in perspective a profile of the coffin.
FIG. 3 is a diagram showing, in a side view, a coffin made of three sections.
DETAILED DESCRIPTION
The described configuration permits the lid, upon backfilling with earth, with a reasonable mass and inertia from the mass will collapse the lid of the coffin and cause the lid to be displaced into the coffin itself. The mass from required to collapse the lid of the coffin would surpass that expected to be present from the force and weight resulting from laying of flowers and the like. In one configuration, the folding arrangement has the general configuration of an accordion bellows.
As a result of downward pressure on the top of the lid and the sides, the lid will be able to be moved and collapse along the bellows. This will especially work, when one throw earth on the lid, by which the inertia of the earth or the moving energy applied to the lid and the arrangement of the bellow, which causes these to be pushed and guided down in to the coffin and over the body itself.
In one configuration, the bottom of the coffin is equipped with U-shaped running ribs. This provides that the coffin itself will be stabilised for bending and cracking. In one particular configuration, the sides of the coffin are equipped with vertically-arranged U-shaped ribs. As a result, the sides on the coffin do not will be able to fold together in vertical direction, but will be more stabilised.
In one particular configuration the box itself of the coffin is made in more sections as two identical sections which are then coupled together, or three sections, which are then coupled together with a middle section, and where the ends are identical.
The disclosed configuration permits less costly moulds for paper pulp, as the mould will be identical for the two ends, and at the same time the mould will be shorter, which also applies for a middle section, if the coffin is made of three sections. The coffin in this way can also be provided in two different lengths, with and without a middle section.
In one particular configuration, the arrangement of the coffin may be made of paper pulp or like perishable material or recycled material.
The disclosed configuration provides that the coffin both will be less costly in production, and in the same time with that it will rapidly deteriorate. This arrangement will further be more environmentally-friendly.
FIG. 1 is a diagram showing a coffin 2 , where there in this 2 is a body 4 , and where one can see, how the lid 1 by a filling with earth 6 collapses down and around above the deceased person 4 .
It can be seen very clearly, how one has made the lid 1 , so that lid 1 itself automatically, by the filling with earth 6 , will collapse down into the coffin 2 , and fold up around 5 and over the deceased person 4 . From the drawing one can also see, how the lid 1 on the edge 3 has a down going board 3 , which guides the lid 1 so that it 1 in the first time do not will slip the sides 10 .
The lid 1 could, if necessary, also be equipped with a locking or latching arrangement, similar to the arrangement of egg cartons, where one close the eggs box by use of tabs, which can be pushed into corresponding holes.
In the lid 1 , according to one alternative, it is possible to place pins through the bellows 7 , so that even a heavy laying 6 of flowers on lid 1 of the coffin 2 would not displace the lid 1 down into the coffin itself 2 .
Alternatively, a locking arrangement may be used a 1 á the above-mentioned egg carton tabs.
The bottom could also be equipped with profiles 8 with long going ribs 8 , which would provide some stability to the body of the coffin 2 itself, and specially, if the coffin 2 is lifted with weight 4 in it 2 . It is possible to mount two longitudinal beams out on, at the edges, or between ribs 11 , with these longitudinal beams laid respectively in the right as in the left side. The handles for lift could ideally so be mounted on these beams.
The beams could even be removed when the coffin 2 has been lowered into the grave, for example by removing the handles out to each sides. One could also leave the handles in place. Alternatively, one make longitudinal beams from millboard or paper or like.
FIG. 2 is a diagram showing a profile of the coffin 2 , and where one clearly here can see the long going profiles 11 or ribs 11 in the bottom, and the vertical profiles 9 or ribs 9 on the sides of the coffin 2 . The profiles 8 , 9 and 11 , as earlier mentioned, assure that the coffin 2 itself will be more stabile, and that it 2 can hold to be lifted with a load 4 , without being prone to collapse or to breakage.
FIG. 3 is a diagram showing, as seen form the side, a coffin 2 made of three sections 12 , where the two end-parts generally are identical, and where the middle part links the coffin 2 together.
|
Coffin ( 2 ), which in its shape, function and its choice of material has a kind environment, but still is stabile, and with a lit ( 1 ), which in its design has means ( 7 ) for by an earth filling ( 6 ) to be able to be discharge ( 5 ) in to the coffin ( 2 ) and down against the body ( 4 ) there has to be buried, as the lid ( 1 ) in its edges ( 3 ) has a folding arrangement ( 7 ).
| 0
|
BACKGROUND OF THE INVENTION
This invention relates to fly traps and more particularly to fly traps of the type employing multiple chambers with inlets for admitting flies in search of food and for preventing their escape. The invention is found to be particularly effective in enticing curious, hungry flies to enter and provides an independent means of segregating and storing dead flies for disposal.
Previously, as in U.S. Pat. No. 3,820,273 fly traps have been proposed wherein a screened chamber contains a fly-attracting food and is entered through a port of restricted size. Once inside, the fly cannot fly back through the port and thus must remain to live within the trap for the remainder of a fly lifetime. This soon creates a collection of old dying flies in the trap, feeding still, and is difficult to handle and particularly difficult to empty. Furthermore, the accumulating dead flies are not attractive to curious newcomers. Multi-compartment traps of similar character have been known such as U.S. Pat. Nos. 145,791; 185,717; and 1,102,642 where provision was made for fed flies to find a means of escape from the food feeding region. Thus an outer second screened chamber was provided and entered through a port of limited size from the first chamber. The port was constructed to essentially prevent fly return. There was no escape from the second chamber. While this got dying flies away from the food, it still created a very visible pile of dead and dying flies surrounded by maggots in the bottom of the second chamber for all other flies to see, as well as becoming unattractive for the fly trap owner. Worse, these devices generally rested table top, somewhere in the vicinity, as for example of one's picnic table. There is, therefore, a need for a new and improved fly trap.
SUMMARY OF THE INVENTION AND OBJECTS
In general, it is an object of the present invention to provide a new and improved fly trap with a dead and dying fly disposal feature including a disposable collection element.
It is a further object of the invention to provide an improved fly trap of the above character which is designed for molded plastic construction.
It is a further object of the invention to provide a fly trap of the above character in which a disposable element can be formed from a plastic bag.
A further object of the invention is to provide a fly trap of the above character which is preferably of the hanging type.
A further object of the invention is to provide a fly trap of the above character in which the feeding of flies and the collection of dead flies is completely segregated in function and in space so that removal of dead flies and feeding of and replenishment of food occurs in different regions sufficient segregated that the same may be accomplished independently and without interference from trapped flies in adjacent regions.
In accordance with the present invention two effects are utilized which rely on the nature of the fly and cooperate to provide a much improved fly trap. Firstly, it is the object of any trap, no matter how difficult to clean, to be able to attract the maximum number of flies, to entrap the same and in order to do this, it must be as fly-attractive as possible. It has been found that by constructing the trap in three regions that its performance can be remarkably increased. Specifically, the present invention provides a central feeding region having an access through a port which is preferably of solid wall construction to provide relatively shielded and darkened porch. The port itself is preferably horizontally elongate and only sufficiently large to admit a walking fly to an internal precipice from which the fly may flit to the food. As the fly looks through the port the vision of the food and all predecessor feeding flies is enhanced by the general darkness of the solid wall of the entry and the contrasting lit area of food and feeding flies. The feeding region is screened thereabout to admit light and to release odors, but to entirely enclose fly movement. In a coaxial construction, a region II coaxial to the feeding region I is provided thereabout as by a second screened cylindrical or frusto-conical wall spaced from the feeding region screen. Access to region II is provided by ports through the feeding region screen so that a fly may exit, being attracted by the generally well lighted outdoors. Flies are known to fly from food in darkened quarters to available light and often impinge upon the flit about one's window for this reason. Once in region II, the well nourished fly finds further exit impossible and thus sets upon some small commotion to escape. However, the fly is no longer nourished and eventually wears out and drops of fatigue or exhaustion. The second region is without floor, however, so that any fly that drops falls into a third region (III) below the second region (II), which third region is a funnel leading to a collection bag.
In coaxial construction, the trap is relatively straight forward to construct although of moderately complex internal construction, but can still be made with a relatively small number of plastic parts. Provision is made for a hinged roof to enable removal of a feeding dish for cleaning and replenishment. The collection bag is secured to the bottom of the trap by a collet which is removable with a partial turn from a bayonet locking lug and is preferably of the totally disposable type so that a simple banding of the bag top is sufficient before throwing the same away and replacing it with a new bag. The bag may be made of perforated plastic to allow drying air to circulate and prevent stagnant accumulation of moisture in the dead fly pack, thus eliminating maggots.
These and other features and objects of the invention will become apparent from the following description and claims taken in conjunction with the accompanying drawings of which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from above showing the fly trap constructed in accordance with the present invention.
FIG. 2 is a side elevational view of the fly trap of FIG. 1.
FIG. 3 is a cross-sectional view taken along the lines 3--3 of FIG. 2.
FIG. 4 is a cross-sectional view taken along the lines 4--4 of FIG. 3.
FIG. 5 is a cross-sectional view of region II taken along the lines 5--5 of FIG. 3.
FIG. 6 is a cross-sectional view of region III taken along the lines 5--5 of FIG. 3.
FIG. 7 is a cross-sectional view taken along the lines 7--7 of FIG. 2.
FIG. 8 is a cross-sectional view taken along the lines 8--8 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2, and 4 the fly trap of the present invention is shown constructed in a coaxial format which is axially symmetric and convenient to manufacture. As a coaxial construction, the trap has several openings which are directed all around so that it can be approached from any direction. Thus, the trap includes a plurality of sheltered entries 10a, b, c, d which serve as balconies or porches and together collectively support the roof 12. A balcony floor 14 lies coaxially around and above and a pair of central, interior sub floors 16 and 18. The interior floors 16,18 are generally frustro-conical in shape, converging downwardly, and spaced to define a conical chute 20 opening into a cylindrical collar 22 at the bottom side of floor 18.
The interior of the fly trap is divided into a central interior chamber to define region I and an exterior screened region coaxial with the first region and spaced therefrom to define a second chamber or region II. The floor 16 is tapered downwardly and serves as a rest for a food dish 24 which is provided with an upstanding stem for removal. Region III is partially defined by the frustro-conical chute developed between sub floors 16 and 18 and empties into a collection bag 26 as will be further described.
The roof 12 is preferably be of peaked construction to facilitate runoff of rain water and thus in conical construction it is a cone. The central portion of the cone including the apex is constructed as a separate part overlapping the lower portion of the cone and is hinged at one side (28) to form an openable hatch cover 30. A sliding bolt 32 secures the side of the hatch cover opposite from the hinge so that can be opened as an access to the food tray. A unified structure of these parts is formed when the slide bolt 32 of the latch is engaged with the closed part 34 fastened to the lower section of the roof. A hanger is attached or formed to arise from the apex of the conical hatch and loops into an open hook 36 for hanging the entire trap as from a tree branch or hanging line.
The portico to region I is defined by three triangular walls 40, 42 and 44 which converge at the roof and are joined thereto at an uppermost lip 45 as by rivets, which may be used throughout if constructed in metal. As the walls diverge, the lateral wall opens laterally outward and the inner wall diverges inwardly and joins to floor 14 to define an entry. An elongate bar opening 46 (FIG. 4) is formed at the lower most part in the rear wall and is just high enough for a fly to walk through. These walls join to meet the floor 14 of the porch or balcony and thereby provide semi-enclosed structure. The floor 14, the balcony side walls and the roof are joined together so that the several entries, 10a, b, c and d including the floor and roof are joined into a unitary structure. The floor 14 at the elongate opening from the entry 10a with the fly trap is arranged to overlap and extend beyond the outer perimeter of the inner floor 16 so that the shelf there provided is a suitable vista for the fly to get a commanding view of the food and feeding flies inside the trap.
However, once the fly succumbs to the temptation and flits into the trap, the fly is no longer in an advantageous position for finding this entry as an egress since, from its lower aspect, the fly must walk across the difficult juncture between the inner floor and the bottom of the entry balcony floor which involves a reentrant angle and then must crawl over the edge from which it previously flit. Flies have six coordinated legs but are not known to crawl over edges. They fly over them. Here such a crawling exit is arranged to be most difficult for the fly even if the fly intelligence were such as to perceive its necessity since the fly almost has to crawl over the edge at 14a and upwardly in order to successfully crawl out opening 46. Such motion apparently does not come easily to flies, for as yet, no fly has been seen to re-emerge from the trap shown.
The food dish 24 may be of any simple sort but preferably has a conical side wall and flat bottom so as to be stably supported on the conical inner floor 16 of the trap. The food can be replaced by lifting on the lifting stem 24a and may be taken through the hatch cover for cleaning and food changing. As is shown, region I containing the food is isolated from region II by the interior screen wall 50 so that opening the cover and changing the food does not involve exposing oneself to a swarm of anxious flies contained within region II or the heap of dying flies in region III.
Once the fly has fed it is natural for the fly to attempt to escape to the light and therefore it flies upwardly and lands on the screen wall 50 separating regions I and II. Shortly the fly finds that it can proceed towards the light through any of the fly ports 52 which start as openings in the screen wall and converge as a funnel with a small opening 52a into region II. This structure is best seen in FIGS. 3 and 4 and is frustro-conical in shape with the opened apex end of the cone extending into region II. Again, once the fly has entered region II its return is substantially impeded by the size of the opening at 52a and by the necessity of crawling around the sharp edge of this opening, a feat not easy for fly feet.
Region II is defined on the inside by the conical screen separating regions I and II and on the outside by the outer screen wall 54 intermittently formed between the entry porches 10. Thus, region II is continuous around and coaxially surrounds region I intermittently to form a significantly visable external aspect of the trap. After the fly enters region II, it is well fed but has no means of escape. Thus it proceeds to set up some fly commotion and to preen itself. Eventually some fly anxiety arises which causes the flies to be busy flying and flitting in region II and on display for all their fly friends to see. This results in a significant attractive nuisance to other flies in the vicinity who come to see what's good about the situation in the trap. Eventually, flies in region II become fatigued, wear out or die after falling from exhaustion or death to the bottom of Region II. Region II has no floor, but leads by openings provided thereabout directly into the chute to region III and the dead, dying and exhausted flies drop into the collection bag leaving only the attractive vital flies to remain in Region II.
The collection bag 26 is attached by a suitable structure to the trap at its lowermost region as by providing the downwardly extending collar with connection pins 55 to which a collet 56 is connected to form a bayonet screw structure for rapid engaging and disengaging of the bag 26 in the space between the collet and the collar. The bag can be of any sort, however, it is preferred that it be relatively accurately made for containment and that it be porous such as porous craft paper or of plastic perforated with small holes to provide adequate ventilation and drying of the dead fly pack within the bag.
The entry porch floor 14 is preferably tilted downwardly and outwardly and is also in a frustro-conical shape so that it is an easier landing perch for the fly. This shape also allows rain to drip away and to run outwardly and away from the trap. A particularly hard, slanted rain may cause water to drip through the fly entry openings, but even that will fall onto the inclined floor 16, run under the dish and drain through drain holes which may be provided in floor 16 and the bag rather than flood the food dish.
In operation, the fly trap of the present invention has been found extremely effective. The rate of fly attraction and entry for the first few flies is typical of fly traps and somewhat slow. But once a few flies accumulate in region II, their appearance to flies in the neighborhood is quite attractive and flies come to the trap in droves. It is believed that this is due principally to the ability of the trap to exit dying flies out of region II before they become a liability. The trap is very easy to clean compared to prior traps, since dead flies do not normally accumulate anywhere in the trap. As has been stated anything capable of free fall is discharged from region II straightforwardly through the floor. Anything in region I that is not removed with the food dish likewise discharges through the floor 16 drains. The bag itself can easily be removed by unsnapping the collet and removing it from the neck of collar. If the bag is sized appropriately, it can be easily banded at its upper end so that its dead fly contents are secure from spillage.
FIG. 5 emphasizes and illustrates the structure of region II showing the effect of its being bounded by inner and outer screen walls which are both needed for light to enter region I for the fly to see food and feeding flies and also needed to draw fed flies to the light and into region II after feeding.
FIGS. 6 and 8 show the structural arrangement of region III. As shown a plurality of walls are provided to form channels between the openings in the floor of region II and the collection bag. These walls define a labyrinth for occluding or blocking out fly return over a substantial segment of the possible return path to region II as seen from the collection end. Thus, any fly proceeding on a path between the walls lying below an entry finds a blind and cannot get out.
While the trap of the invention is readily constructed in sheet metal and wire screen, it can also be made for mass production in a few pieces of plastic molded parts since there are more than one plane of symmetry along which a part line can be taken.
|
A multiple chamber fly trap contains approximately concentric screens defining a region within the inner screen into which the flies enter for the bait, an annular second region between the screens into which the flies enter to escape to the light, and a third region below the second region into which the flies drop after exhaustion. A plurality of openings between the consecutive regions allow passage of the flies from the first to the second to the third and into a removable collector which is preferably a disposable bag.
| 0
|
BACKGROUND
The preparation of vinyl halide-containing polymers by suspension polymerization of vinyl halide either alone or in combination with other monomers is well-known. Briefly, the process comprises adding water, the monomer, initiator and suspending agent to the reaction vessel which is jacketed. The reaction mass is heated by injecting steam into the reaction vessel. Once at desired temperature the reaction is maintained at a predetermined temperature by controlling the temperature of the water in the jacket. The reaction is allowed to proceed until it reaches a predetermined conversion level. In some instances the polymerization is terminated by the addition of a material known as a chain-stopping agent. Upon reaching the desired conversion level, the pressure is released by venting usually to a compressor. This pressure release is often called stripping since it reduces the amount of unreacted monomer. The resulting product is a slurry of vinyl halide-containing polymer in water, which contains also unreacted vinyl halide.
More recently, attention has been directed to the problem of preparing polyvinyl halide-containing polymers which contain only a minor amount, if any, of unreacted vinyl halide. My invention is directed to this problem.
PRIOR ART
It is known to add a plasticizer to the initial polymerization recipe in the preparation of vinyl halide-containing polymers by suspension polymerization.
To my knowledge, it is not known to "tail-peak" the reaction mass prior to stripping. Also, the combination of (1) conducting the polymerization in the presence of a plasticizer and (2) "tail-peaking" the reaction mass prior to stripping is not known.
BRIEF SUMMARY OF THE INVENTION
Briefly stated, the present invention is directed to a method of preparing vinyl halide-containing polymers, which contain a reduced amount of unreacted vinyl halide, by an improvement in the suspension polymerization of a monomer selected from the group consisting of a vinyl halide and a mixture of a vinyl halide and a monomer copolymerizable therewith, wherein the improvement comprises polymerizing the monomer to a conversion level of at least about 60 percent, and thereupon increasing the temperature of polymerization by about 14 to about 62° C., with the additional characteristic that the increased polymerization temperature does not exceed 100° C.
In one aspect the improved process contains the additional feature of conducting the polymerization in the presence of a minor amount of plasticizer.
Stated differently, the present invention is directed to a method of preparing vinyl halide-containing polymers, which contain a reduced amount of unreacted vinyl halide, wherein the method comprises:
A. FORMING A SUSPENSION POLYMERIZATION REACTION MIXTURE COMPRISING (I) MONOMER SELECTED FROM THE GROUP CONSISTING OF A VINYL HALIDE AND A MIXTURE OF A VINYL HALIDE AND A MONOMER COPOLYMERIZABLE THEREWITH, (II) INITIATOR, (III) SUSPENDING AGENT AND (IV) WATER,
B. POLYMERIZING THE MONOMER TO A CONVERSION LEVEL OF AT LEAST ABOUT 60 PERCENT,
C. THEREUPON INCREASING THE TEMPERATURE OF POLYMERIZATION OF ABOUT 14 TO ABOUT 62° C., with the additional characteristic that the increased polymerization temperature does not exceed 100° C., and
d. stripping the reaction admixture containing the polymer.
The polymer is recovered by conventional means.
In one aspect, the polymerization reaction mixture contains a minor amount of a conventional plasticizer.
DETAILED DESCRIPTION
The vinyl halide used in my invention preferably is vinyl chloride. However, other vinyl halides, such as vinyl bromide and vinyl fluoride, can be used. The invention will be illustrated using vinyl chloride.
My invention is also suitable for use with mixtures of a vinyl halide and a monomer copolymerizable therewith. Examples of monomers which are copolymerizable with vinyl chloride include vinylidene chloride; vinyl acetate; vinyl alkyl esters (such as vinyl neodecanoate); ethylene; propylene; isobutylene; acrylonitrile; ester of acrylic and methacrylic acids such as methyl, ethyl, butyl, propyl, 2-ethylhexyl, hexyl acrylate and methacrylate; esters of maleic acid such as diethyl, dipropyl, dihexyl, and dioctyl maleate.
Any of the initiators ordinarily used in the suspension polymerization of vinyl chloride can be used in my process. Examples of suitable initiators include organic peroxides such as benzoyl peroxide, lauroyl peroxide and diisopropyl peroxydicarbonate; azo compounds such as azobisisobutylronitrile; and the like oil-soluble catalysts.
Also, any of the suspending agents normally used in the suspension polymerization of vinyl chloride can be used in my process. Examples of suitable suspending agents include natural high molecular substances such as starch and gelatin, and synthetic high molecular substances such as partially saponified polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxypropoxymethyl cellulose, maleic anhydride-vinyl ether copolymer and polyvinyl pyrrolidine and the like.
Inasmuch as there are many references (patents, books, encyclopedias, etc.) which teach the amounts of water, monomer, initiator and suspending agent, which are used in suspension polymerization processes, it is not believed necessary to describe suitable amounts herein.
Any of the conventional primary or secondary plasticizers, which are conventionally used in the preparation of vinyl polymers, are suitable for use in the process of my invention.
Examples of suitable plasticizers include esters of polycarboxylic acids, such as phthalic acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, pimelic acid, azelaic acid, suberic acid 1,4-cyclohexanedicarboxylic acid, naphthalic acid, dinicotinic acid, acridinic acid, and 3,4-quinolinedicarboxylic acid. Also, suitable are phosphoric esters such as trioctyl phosphate, tritolyl phosphate and trixylyl phosphate.
Particularly suitable plasticizers include the C 2 -C 14 alkyl esters of dicarboxylic acids. The term dicarboxylic acids as used herein includes both aromatic and aliphatic acids. Examples of particularly suitable plasticizers include dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-iso-octyl phthalate, dinonyl phthalate, di-isodecyl-phthalate, ditridecyl phthalate, butyl benzyl phthalate, dibutyl adipate, dihexyl adipate, dioctyl adipate, dibutyl sebacate and dioctyl sebacate.
Of the foregoing materials, the phthalic acid esters are preferred.
Expressed as parts per hundred parts of monomer a suitable amount of plasticizer for use in my invention is about 0.1 to about 10. On the same basis, a preferred amount of plasticizer is about 0.3 to about 5.
PROCESS CONDITIONS
The initial part of the process of my invention is conducted under standard suspension polymerization conditions. Normally, the temperature is in the range of about 38 to about 71° C. More usually, the temperature is in the range of about 49 to about 66° C. As is wellknown in the art the reaction occurs at an increased pressure.
The important feature of the process of my invention is increasing the temperature of polymerization substantially at a predetermined conversion level. The amount of temperature increase is in the range of about 14° to about 62° C., more usually in the range of about 14° to about 33° C., with the additional limitation that the polymerization temperature does not exceed 100° C. The conversion level suitably is at least 60 percent, more suitably at least 70 percent and preferably at least 75 weight percent. A convenient means of determining the desired conversion level is by observing the pressure on the reaction vessel. A drop of pressure in the order 0.7 atmosphere indicates that the conversion has reached a level where the temperature can be increased.
Normally, the temperature increase occurs over a period of about 15 minutes to about five hours.
As indicated hereinbefore the temperature of the polymerization reaction is controlled by the flow of water in the jacket surrounding the reactor.
One convenient means of allowing the desired temperature increase is by utilizing the heat of reaction. In other words, less or no cooling water is used. In some instances, it may be necessary to use external heat to attain the desired temperature.
When the reaction nears completion, the pressure in the reactor begins to drop. At this point and while the reaction admixture is at or near the maximum temperature, stripping is begun. "Stripping" is wellknown to those skilled in this art. Usually, it means venting the vapors, which contain unreacted monomer, to a collecting vessel. The pressure on the reaction vessel is allowed to go to atmospheric. In many instances, the stripping is extended by applying a vacuum to the reactor containing the slurry.
The slurry is then passed to another vessel. If desired, it can be subjected to steam stripping, or other treatment, to remove additional unreacted vinyl halide. It is then processed by conventional means. For example, the water is removed by filtration, after which the polymer is dried.
My process has two distinct advantages. As noted hereinbefore it produces a product having a reduced amount of unreacted vinyl halide. In addition it results in a higher conversion of monomer to polymer. For example, my process results in a conversion of 90 to 92 percent. On the same basis, without tail-peaking, the process normally results in a conversion of 78 to 87 percent.
My process results in a product having a larger amount of low molecular weight material. However, the product is still useful in many applications, such as manufacture of pipe.
In order to disclose the nature of the present invention still more clearly, the following examples will be given. It is to be understood that the invention is not to be limited to the specific conditions or details set forth in these examples except insofar as such limitations are specified in the appended claims.
The amounts of, and nature of, materials used were as follows:
______________________________________ Weight (In Parts)______________________________________Deionized Water 175Vinyl Chloride 100Suspending Agent.sup.(1) 0.08Initiator.sup.(2) 0.066______________________________________ .sup.(1) Hydroxy propyl methylcellulose .sup.(2) 2-ethylhexyl peroxydicarbonate
EXAMPLE 1
This example shows the improvement obtained using "tail-peaking."
Run A
The materials described in the foregoing were added to a jacketed reaction vessel. After the reaction was begun the temperature was 56° C. with the pressure being 7 atmospheres. When the pressure dropped 0.7 atmosphere (at a conversion level of about 75 percent) the temperature was increased to 79° C. When the pressure dropped to 6.1 atmospheres stripping of the reaction was begun, i.e., the overhead vapors were allowed to escape to a collecting vessel. After the pressure reached 0 atmosphere, a vacuum was pulled on the slurry for 20 minutes while the temperature was 79° C. The water-polyvinyl chloride slurry was cooled and then withdrawn from the reaction vessel and the polyvinyl chloride was recovered by filtering and then dried. The amount of vinyl chloride in the product is shown in Table I.
Run B
The materials were the same as in Run A. The procedure was the same as in Run A with the exception that the temperature was maintained at 56° C. and not increased to 79° C. Stripping was begun while the temperature was 56° C. The amount of vinyl chloride in the product is shown in Table I.
EXAMPLE 2
This example shows the improvement obtained using "tail-peaking" in combination with a small amount of plasticizer.
The plasticizer was dioctyl phthalate. Runs were made using 0.55 and 1.0 parts of dioctyl phthalate per 100 parts of monomer. A comparative run was made. The results are shown in Table I.
Table I______________________________________ DOPRun No. "Tail-peaking" (phm) ppm Vinyl Chloride*______________________________________Ex. 1-A Yes No 200Ex. 1-B No No 1100Ex. 2-A Yes No 215Ex. 2-B Yes 0.55 86Ex. 2-C Yes 1.0 112______________________________________ *Based on dry resin
EXAMPLE 3
This example also shows the improvement obtained using "tail-peaking."
The materials described in the foregoing were added to a jacketed reactor vessel.
The procedure was similar to that of Run A of Example 1. In Run A of this example, the temperature was raised to 79° C. In Run B, the temperature was raised to 88° C. The amount of vinyl chloride in the products is shown in Table II.
Table II______________________________________Max. Reactor TemperatureTemp. ° C. Increase ° C. ppm Vinyl Chloride*______________________________________Run A 79 23 1200Run B 88 32 400______________________________________ *Based on dry resin
Thus, having described the invention in detail, it will be understood by those skilled in the art that certain variations and modifications may be made without departing from the spirit and scope of the invention as defined herein and in the appended claims.
|
An improvement in the method of preparing vinyl halide-containing polymers by suspension polymerization is disclosed. Briefly, the improvement comprises "tail-peaking" the reaction mass prior to stripping in order to remove vinyl halide. By "tail-peaking" is meant increasing the temperature of polymerization towards the latter part of the polymerization reaction. In one aspect the improvement comprises the additional feature of conducting the polymerization in the presence of a plasticizer.
| 2
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part of Ser. No. 435,065, filed May 8, 1995.
BACKGROUND OF THE INVENTION
[0002] This invention relates to the spinning of synthetic polymeric yarns. In a specific embodiment, the invention relates to spinning poly(trimethylene terephthalate) into yarn suitable for carpets.
[0003] Polyesters prepared by condensation polymerization of the reaction product of a diol with a dicarboxylic acid can be spun into yarn suitable for carpet fabric. U.S. Pat. No. 3,998,042 describes a process for preparing poly(ethylene terephthalate) yarn in which the extruded fiber is drawn at high temperature (160° C.) with a steam jet assist, or at a lower temperature (95° C.) with a hot water assist. Poly(ethylene terephthalate) can be spun into bulk continuous filament (BCF) yarn in a two-stage drawing process in which the first stage draw is at a significantly higher draw ratio than the second stage draw. U.S. Pat. No. 4,877,572 describes a process for preparing poly(butylene terephthalate) BCF yarn in which the extruded fiber is drawn in one stage, the feed roller being heated to a temperature 30° C. above or below the Tg of the polymer and the draw roller being at least 100° C. higher than the feed roll. The application of conventional polyester spinning processes to prepare poly(trimethylene terephthalate) BCF results in yarn which is of low quality and poor consistency. It would be desirable to have a process for preparing high-quality BCF carpet yarn from poly(trimethylene terephthalate).
[0004] It is therefore an object of the invention to provide a process for preparing high-quality bulk continuous filament yarn from poly(trimethylene terephthalate).
SUMMARY OF THE INVENTION
[0005] According to the invention, poly(trimethylene terephthalate) is formed into a bulk continuous filament yarn by a process comprising:
[0006] (a) melt-spinning poly(trimethylene terephthalate) at a temperature within the range of about 240° C. to about 280° C. to produce a plurality of spun filaments;
[0007] (b) cooling the spun filaments;
[0008] (c) converging the spun filaments into a yarn;
[0009] (d) drawing the yarn at a first draw ratio within the range of about 1.01 to about 2 in a first drawing stage defined by at least one feed roller and at least one first draw roller, each of said at least one feed roller operated at a temperature less than about 100° C. and each of said at least one draw roller heated to a temperature greater than the temperature of said at least one feed roller and within the range of about 50 to about 150° C.;
[0010] (e) subsequently drawing the yarn at a second draw ratio of at least about 2.2 times that of the first draw ratio in a second drawing stage defined by said at least one first draw roller and at least one second draw roller, each of said at least one second draw roller heated to a temperature greater than said at least one first draw roller and within the range of about 100 to about 200° C.; and
[0011] (f) winding the drawn yarn.
[0012] The process may optionally include texturing the drawn yarn prior to or after winding step (f).
[0013] The process of the invention permits the production of poly(trimethylene terephthalate) bulk continuous filament yarn suitable for high-quality carpet.
BRIEF DESCRIPTION OF THE FIGURES
[0014] [0014]FIG. 1 is a schematic diagram of one embodiment of the invention yarn preparation process.
[0015] [0015]FIG. 2 is a schematic diagram of a second embodiment of the invention process.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The fiber-spinning process is designed specifically for poly(trimethylene terephthalate), the product of the condensation polymerization of the reaction product of trimethylene diol (also called “1,3-propane diol”) and a terephthalic acid or an ester thereof, such as terephthalic acid and dimethyl terephthalate. The poly(trimethylene terephthalate) may be derived from minor amounts of other monomers such as ethane diol and butane diol as well as minor amounts of other diacids or diesters such as isophthalic acid. Poly(trimethylene terephthalate) having an intrinsic viscosity (i.v.) within the range of about 0.8 to about 1.0 dl/g, preferably about 0.86 to about 0.96 dl/g (as measured in a 50/50 mixture of methylene chloride and trifluoroacetic acid at 30° C.) and a melting point within the range of about 215 to about 230° C. is particularly suitable. The moisture content of the poly(trimethylene terephthalate) should be less than about 0.005% prior to extrusion. Such a moisture level can be achieved by, for example, drying polymer pellets in a dryer at 150-180° C. until the desired dryness has been achieved.
[0017] One embodiment of the invention process can be described by reference to FIG. 1. Molten poly(trimethylene terephthalate) which has been extruded through a spinneret into a plurality of continuous filaments 1 at a temperature within the range of about 240 to about 280° C., preferably about 250 to about 270° C., and then cooled rapidly, preferably by contact with cold air, is converged into a multifilament yarn and the yarn is passed in contact with a spin finish applicator, shown here as kiss roll 2 . Yarn 3 is passed around denier control rolls 4 and 5 and then to a first drawing stage defined by feed roll 7 and draw roll 9 . Between rolls 7 and 9 , yarn 8 is drawn at a relatively low draw ratio, within the range of about 1.01 to about 2, preferably about 1.01 to about 1.35. Roller 7 is maintained at a temperature less than about 100° C., preferably within the range of about 40 to about 85° C. Roller 7 can be an unheated roll, in which case its temperature of operation will be somewhat elevated (30-45° C.) due to friction and the temperature of the spun fiber. Roller 9 is maintained at a temperature within the range of about 50 to about 150° C., preferably about 90 to about 140° C.
[0018] Drawing speeds of greater than 1000 m/min. are possible with the invention process, with drawing speeds greater than 1800 m/min. desirable because of the high tenacity of the resulting yarn.
[0019] Drawn yarn 10 is passed to a second drawing stage, defined by draw rolls 9 and 11 . The second-stage draw is carried out at a relatively high draw ratio with respect to the first-stage draw ratio, generally at least about 2.2 times that of the first stage draw ratio, preferably at a draw ratio within the range of about 2.2 to about 3.4 times that of the first stage. Roller 11 is maintained at a temperature within the range of about 100 to about 200° C. In general, the three rollers will be sequentially higher in temperature. The selected temperature will depend upon other process variables, such as whether the BCF is made with separate drawing and texturing steps or in a continuous draw/texturing process, the effective heat transfer of the rolls used, residence time on the roll, and whether there is a second heated roll upstream of the texturing jet. Drawn fiber 12 is passed in contact with optional relax roller 13 for stabilization of the drawn yarn. Stabilized yarn 14 is passed to optional winder 15 or is sent directly to the texturing process.
[0020] The drawn yarn is bulked by suitable means such as a hot air texturing jet. The preferred feed roll temperature for texturing is within the range of about 150 to about 220° C. The texturing air jet temperature is generally within the range of about 150 to about 210° C., and the texturing jet pressure is generally within the range of about 50 to about 120 psi to provide a high-bulk BCF yarn. Wet or superheated steam can be substituted for hot air as the bulking medium.
[0021] [0021]FIG. 2 shows a second embodiment of the two-stage drawing process showing texturing steps downstream of the drawing zone. Molten poly(trimethylene terephthalate) is extruded through spinneret 21 into a plurality of continuous filaments 22 and is then quenched by, for example, contact with cold air. The filaments are converged into yarn 24 to which spin finish is applied at 23 . Yarn 27 is advanced to the two-stage draw zone via rolls 25 and 26 , which may be heated or non-heated.
[0022] In the first draw stage, yarn 31 is drawn between feed roll 28 and draw roll 29 at a draw ratio within the range of about 1.01 and about 2. Drawn yarn 32 is then subjected to a second draw at a draw ratio at least about 2.2 times the first draw ratio, preferably a draw ratio within the range of about 2.2 to about 3.4 times that of the first draw. The temperature of roll 28 is less than about 100° C. The temperature of draw roll 29 is within the range of about 50 to about 150° C. The temperature of draw roll 30 is within the range of about 100 to about 200° C. Drawn yarn 33 is advanced to heated rolls 34 and 35 to preheat the yarn for texturing. Yarn 36 is passed through texturing air jet 37 for bulk enhancement and then to jet screen cooling drum 38 . Textured yarn 39 is passed through tension control 40 , 41 and 42 and then via idler 43 to optional entangler 44 for yarn entanglement if desired for better processing downstream. Entangled yarn 45 is then advanced via idler 46 to an optional spin finish applicator 47 and is then wound onto winder 48 . The yarn can then be processed by twisting, texturing and heat-setting as desired and tufted into carpet as is known in the art of synthetic carpet manufacture.
[0023] Poly(trimethylene terephthalate) yarn prepared by the invention process has high bulk (generally within the range of about 20 to about 45%, preferably within the range of about 26 to about 35%), resilience and elastic recovery, and is useful in the manufacture of carpet, including cut-pile, loop-pile and combination-type carpets, mats and rugs. Poly(trimethylene terephthalate) carpet has been found to exhibit good resiliency, stain resistance and dyability with disperse dyes at atmospheric boil with optional carrier.
EXAMPLE 1
Effect of Intrinsic Viscosity on Poly(trimethylene terephthalate) Fiber Drawing
[0024] Four poly(trimethylene terephthalate) polymers having intrinsic viscosities of 0.69, 0.76, 0.84 and 0.88 dl/g, respectively, were each spun into 70 filaments with trilobal cross-sections using a spinning machine having a take-up and drawing configuration as shown in FIG. 1. Roll 1 (see detail below) was a double denier control roll; roll 2 ran at a slightly higher speed to maintain a tension and act as a feed roll for drawing. First stage drawing took place between rolls 2 and 3 , and second-stage drawing took place between rolls 3 and 4 . The drawn yarn contacted relax roll 5 prior to wind-up. The spin finish was a 15% Lurol PF 4358-15 solution from G. A. Goulston Company applied with a kiss roll.
[0025] Fiber extrusion and drawing conditions for each polymer were as follows:
Extrusion Conditions Polymer IV (dl/g): Units 0.84, 0.88 0.69, 0.76 Extruder Temp. Profile: Zone 1 ° C. 230 225 Zone 2 ° C. 250 235 Zone 3 ° C. 250 235 Zone 4 ° C. 250 235 Melt Temp. ° C. 255 240 Extrusion Pack Pressure psi 1820-2820 500-1300 Denier Control Roll Speed m/min. 225 220 Fiber Drawing Conditions Polymer IV (dl/g) 0.88 0.84 0.76 0.69 Roll Temp.: ° C. Roll 2 80 80 80 80 Roll 3 95 95 95 95 Roll 4 155 155 155 155 Roll 5 RT RT RT RT Roll Speeds: m/min. Roll 2 230 230 230 230 Roll 3 310 310 404 404 Roll 4 1020 1165 1089 1089 Roll 5 1035 1102 1075 1075 First Stage Draw Ratio 1.35 1.35 1.76 1.76 Second Stage Draw Ratio 3.29 3.29 2.70 2.70
[0026] [0026] TABLE 1 Fiber tensile properties are shown in Table 1. I.V. Yarn Count Tenacity Run (dl/g) (den.) (g/den.) % Elongation 1 0.69 1182 1.51 70.7 2 0.76 1146 1.59 79.7 3 0.84 1167 2.03 89.0 4 0.88 1198 2.24 67.5
[0027] Poly(trimethylene terephthalate) of intrinsic viscosities 0.69 and 0.76 (Runs 1 and 2) gave yarn of inferior tensile properties compared with the yarn of Runs 3 and 4. These polymers were re-spun at a lower extruder temperature profile. Although they could be spun and drawn, the fibers had high die swell. When the fiber cross-sections were examined with an optical microscope, the 0.69 i.v. fibers swelled to a point that they were no longer trilobal in shape and resembled delta cross-sections. They also had relatively low tenacity.
EXAMPLE 2
Two-Stage Drawing of PTT Fibers
[0028] 0.88 i.v. poly(trimethylene terephthalate) was extruded into 72 filaments having trilobal cross-section using a fiber-spinning machine having take-up and drawing configurations as in Example 1. Spin finish was applied as in Example 1. Extrusion and drawing conditions were as follows.
Extrusion Conditions Extruder Temperature Profile: Units Zone 1 ° C. 230 Zone 2 ° C. 260 Zone 3 ° C. 260 Zone 4 ° C. 260 Melt Temp. ° C. 265 Denier Control Roll Speed m/min. 230
[0029] [0029] Fiber Drawing Conditions Runs Units 5 6 7 8 9 10 11 Roll 2 Temp./Speed ° C./m/min 80/235 80/235 100/235 100/235 100/235 100/235 100/235 Roll 3 Temp./Speed ° C./m/min 90/317 100/286 100/817 100/817 100/817 100/993 100/945 Roll 4 Temp./Speed ° C./m/min 155/1123 100/1021 155/1047 140/1103 140/1145 130/1044 140/996 Roll 5 Temp./Speed ° C./m/min RT/1096 RT/1011 RT/1029 RT/1082 RT/1134 RT/1019 RT/981 1st Stage Draw Ratio 1.35 1.22 3.48 3.48 3.48 4.23 4.02 2nd Stage Draw Ratio 3.55 3.87 1.28 1.35 1.40 1.05 1.05 Total Draw Ratio 4.79 4.36 4.48 4.70 4.87 4.44 4.22 Yarn Count, den. den. 1225 1281 1278 1185 1210 1288 Tenacity, g/den. g/den. 1.95 1.95 1.61 1.32 1.85 1.11 Elongation % 55 75 70 76 78 86
[0030] It was observed during spinning and drawing that, when the first-stage draw ratio (between rolls 2 and 3 ) was less than about 1.5, as in Runs 5 and 6, there were fewer broken filaments and the tenacities of the filaments were generally higher than when first-stage draw was higher than about 1.5. When the first-stage draw was increased to greater than 3 (Runs 7, 8, 9, 10, and 11), it was observed that the fibers had a white streaky appearance, the threadlines were loopy, and there were frequent filament wraps on the draw rolls. The process was frequently interrupted with fiber breaks.
EXAMPLE 3
Spinning, Drawing and Texturing Poly(trimethylene terephthalate) BCF to High Bulk
[0031] The extrusion conditions in this experiment were the same as in Example 2. The fibers were spun, drawn and wound as in Example 1. They were then textured by heating the fibers on a feed roll and exposing the fibers to a hot air jet. The textured fibers were collected as a continuous plug on a jet-screen cooling drum. Partial vacuum was applied to the drum to pull the ambient air to cool the yarns and keep them on the drum until they were wound. The yarns were air entangled between the drum and the winder. The feed roll and texturizer air jet temperatures were kept constant, and the air jet pressure was varied from 50 to 100 psi to prepare poly(trimethylene terephthalate) BCF of various bulk levels.
[0032] Drawing and texturing conditions were as follows.
Drawing Conditions Rolls Temperature, ° C. Speed, m/min. Roll 1 RT 225 Roll 2 80 230 Roll 3 95 264 Roll 4 90 1058 Roll 5 110 1042 Texturing Conditions Feed Roll Temperature, ° C. 180 Feed Roll Speed, m/min. 980 Air Jet Temperature, ° C. 180 Interlacing Pressure, psi 10
[0033] Yarn bulk and shrinkage were measured by taking 18 wraps of the textured yarn in a denier creel and tying it into a skein. The initial length L 0 of the skein was 22.1 inches in English unit creel. A 1 g weight was attached to the skein and it was hung in a hot-air oven at 130° C. for 5 minutes. The skein was removed and allowed to cool for 3 minutes. A 50 g weight was then attached and the length L 1 was measured after 30 seconds. The 50 g weight was removed, a 10 Lb weight was attached, and the length L 2 was measured after 30 seconds. Percent bulk was calculated as (L 0 −L 1 )/L 0 ×100% and shrinkage was calculated as (L 0 −L 2 )/L 0 ×100%. Results are shown in Table 2.
TABLE 2 Package No. Yarn Count, den. % Bulk % Shrinkage T50 1437 32.6 3.6 T60 1406 35.7 2.7 T70 1455 39.4 3.2 T80 1500 38.0 3.6 T90 1525 37.6 4.1 T100 1507 38.0 3.6
[0034] The experiment showed that poly(trimethylene terephthalate) BCF can be textured to high bulk with a hot air texturizer.
EXAMPLE 4
Carpet Resiliency Comparison
[0035] Poly(trimethylene terephthalate) BCF yarns were made in two separate steps: (1) spinning and drawing set-up as in Example 1 and (2) texturing. Extrusion, drawing and texturing conditions for the poly(trimethylene terephthalate) yarns were as follows.
Extrusion Conditions Extruder Temperature Units Zone 1 ° C. 240 Zone 2 ° C. 255 Zone 3 ° C. 255 Zone 4 ° C. 255 Melt Temperature ° C. 260 Pack Pressure psi 1830
[0036] [0036] Drawing Conditions Units Roll 1 Temp. ° C./m/min. RT/223 Roll 2 Temp. ° C./m/min. 80/230 Roll 3 Temp. ° C./m/min. 95/288 Roll 4 Temp. ° C./m/min. 150/1088 Roll 5 Temp. ° C./m/min. RT/1000
[0037] [0037] Texturing Conditions Units Feed Roll Temp. ° C. 180 Feed Roll Speed m/min. 980 Air Jet Temp. ° C. 180 Air Jet Pressure psi 90 Interlacing Pressure psi 10
[0038] The yarn produced was 1150 denier with 2.55 g/den tenacity and 63% elongation. The textured yarn was twisted, heat set as indicated, and tufted into carpets. Performances of the poly(trimethylene terephthalate) carpets were compared with a commercial 1100 denier nylon 66 yarn. Results are shown in Table 3.
TABLE 3 Accelerated Floor % Loss Heat Setting Traffic in Pile Run Twist/Inch Conditions Rating Thickness 12 (Poly(trimethylene 4.5 × 4.5 270° F. 3.75 2.4 terephthalate) Autoclave 13 (Poly(trimethylene 4.5 × 4.5 180° C. Seussen 3.5 7.1 terephthalate) 14 (Poly(trimethylene 5.0 × 5.0 270° F. 3.75 1.7 terephthalate) Autoclave 15 nylon 66 4.0 × 4.0 270° F. 3.0 6.4 Autoclave 16 nylon 66 4.0 × 4.0 190° C. Seussen 3.5 4.5
[0039] The heat-set yarns were tufted into 24 oz. cut-pile Saxony carpets in ⅛″ gauge, {fraction (9/16)}″ pile height, and dyed with disperse blue 56 (without a carrier) at atmospheric boil into medium blue color carpets. Visual inspection of the finished carpets disclosed that the poly(trimethylene terephthalate) carpets (Runs 12, 13 and 14) had high bulk and excellent coverage which were equal to or better than the nylon controls (Runs 15 and 16). Carpet resiliency was tested in accelerated floor trafficking with 20,000 footsteps. The appearance retention was rated 1 (severe change in appearance), 2 (significant change), 3 (moderate change), 4 (slight change) and 5 (no change). As can be seen in Table 3, the poly(trimethylene terephthalate) carpets were equal to or better than the nylon 66 controls in the accelerated walk tests and in percent thickness loss.
EXAMPLE 5
One-Step Processing of Poly(trimethylene terephthalate) BCF Yarn from Spinning to Texturing
[0040] Poly(trimethylene terephthalate) (i.v. 0.90) was extruded into 72 trilobal cross-section filaments. The filaments were processed on a line as shown in FIG. 2 having two cold rolls, three draw rolls and double yarn feed rolls prior to texturing. The yarns were textured with hot air, cooled in a rotating jet screen drum and wound up with a winder. Lurol NF 3278 CS (G. A. Goulston Co.) was used as the spin finish. Texturing conditions were varied to make poly(trimethylene terephthalate) BCF yarns having different bulk levels. Extrusion, drawing, texturing and winding conditions were as follows.
Extrusion Conditions Extruder Temperature Profiles Units Zone 1 ° C. 240 Zone 2 ° C. 260 Zone 3 ° C. 260 Zone 4 ° C. 265 Melt Temperature ° C. 265 Pump Pressure psi 3650
[0041] [0041] Drawing Conditions Temperature ° C. Speed, m/min. Cold Roll 1 RT 211 Cold Roll 2 RT 264 Draw Roll 1 50 290 Draw Roll 2 90 330 Draw Roll 3 110 1100
[0042] The yarns were twisted, heat set and tufted into carpets for performance evaluation. Results are shown in Table 4.
TABLE 4 Sample Feed Roll Texturing Texturizing Jet Yarn Count, Accelerated Walk Number Temp, ° C. Jet temp., ° C. Press., psi den. % Bulk % Shrinkage Test Rating 1 150 180 70 1490 19.2 1.58 3.25 2 150 180 110 1420 26 1.59 3.5 3 150 200 110 1546 30.5 1.59 3.0 4 180 180 70 1429 24.6 2.04 3.0 5 180 180 110 1496 29.8 1.81 3.5 6 180 200 70 1475 26.5 1.36 2.75 7 180 200 110 1554 32.8 0.86 3.0 8 150 190 90 1482 26 2.31 3.25 9 180 190 90 1430 29 1.58 3.5 10 165 190 90 1553 29 2.26 3.75 Nylon 6 3.5 Nylon 66 3.5
EXAMPLE 6
Effects of Draw Ratio and Roll Temperature on Yarn Properties
[0043] Poly(trimethylene terephthalate) (0.90 i.v.) was spun into 72 filaments with trilobal cross-sections using a machine as described in Example 5. Extrusion conditions were as follows.
Extrusion Conditions Extruder Temperature Profiles Units Zone 1 ° C. 240 Zone 2 ° C. 260 Zone 3 ° C. 260 Zone 4 ° C. 260 Melt Temperature ° C. 260
[0044] The poly(trimethylene terephthalate) BCF yarns and commercial nylon 6 and 66 yarns were tufted into 32 oz. {fraction (5/32)} gauge cut-pile Saxony carpets having {fraction (20/32)}″ pile height. They were walk-tested with 20,000 footsteps accelerated floor trafficking for resiliency and appearance retention comparisons. Roll conditions and results are shown in Table 5.
EXAMPLE 7
Use of Low First-Stage Draw Ratio
[0045] Poly(trimethylene terephthalate) (0.9 i.v.) was spun into 69 filaments with trilobal cross-sections using a drawing and texturing configuration similar to that shown in FIG. 1, with the yarn passing via unheated haul-off Roll 1 , first-stage draw between Roll 1 and draw Roll 2 , and second-stage draw between Roll 2 and dual Roll 3 . The drawn yarns were then textured, relaxed and wound up. Extrusion conditions were as follows.
TABLE 5 Sample: 1 2 3 4 5 nylon 6 nylon 66 Roll 1 Temp ° C. 50 50 50 50 50 Roll 2 Temp ° C. 90 90 90 90 90 Roll 3 Temp. ° C. 110 110 110 150 150 Roll 1 speed m/min. 290 290 290 290 290 Roll 2 Speed m/min. 330 330 330 330 330 Roll 3 Speed m/min. 1000 1100 1150 1100 1000 Draw Ratio 3.45 3.79 3.97 3.97 3.45 Feed Roll Temp. ° C. 165 165 165 165 165 Feed Roll Speed m/min. 1000 1100 1150 1100 1000 Texturing Jet Temp. ° C. 190 190 190 190 190 Texturing Jet Pressure psi 90 90 90 90 90 Interlacing Pressure psi 30 30 30 30 30 Bulk % 26.1 31.6 31.9 35.8 33 Shrinkage % 1.75 2.04 2.13 2.26 192 Walk test Rating 4.0 3.5 3.5 3.5 3.5 3.5 3.5
[0046] [0046] Extrusion Conditions Extruder Temp. Profiles Trial 1 Trial 2 Zone 1 230° C. 230 Zone 2 260 245 Zone 3 260 255 Zone 4 260 255
[0047] The speed and temperature of the rolls, texturing conditions and yarn tensile properties are shown in Table 6. In Trial 1, the relax roll was a single roll with a follower, and in Trial 2, the relax roll was a dual roll. The spin finish was Goulston Lurol 3919 applied as a 25-30% emulsion. The first stage draw was about 1.13 (Trial 1) and 1.015 (trial 2) and second-stage draws were about 2.5 and 3.2. Although heat was not added to Roll 1 in these trials, the heat of operation would be expected to be above room temperature. As can be seen from Table 6, the yarn had excellent tenacity and elongation at speeds greater than 2000 m/min.
TABLE 6 Trial 1 Trial 2 Roll Speeds (m/min.): Roll 1 430 754 Roll 2 486 765 Dual Roll 3 1226 2500 Relax Roll 1176 Relax Dual Roll 4 2010 Winder 1156 1995 Roll Temperatures (° C.): Roll 1 Unheated Unheated Roll 2 49 65 Roll 3 135 165 Relax Dual Roll 4 Unheated Unheated Texturizing Conditions: Air Jet Temperature (° C.) 163 190 Air Jet Pressure (psi) 80 95 Interlacer Pressure (psi) 20 30 Yarn Properties: Yarn Count (denier) 1450 1328 Tenacity (g/den) 1.3 1.98 Elongation (%) 44 50.4
|
Poly(trimethylene terephthalate) is formed into a bulk continuous filament yarn by a process comprising:
(a) melt-spinning poly(trimethylene terephthalate) at a temperature within the range of about 240 to about 280° C. to produce a plurality of spun filaments;
(b) cooling the spun filaments;
(c) converging the spun filaments into a yarn;
(d) drawing the yarn at a first draw ratio within the range of about 1.01 to about 2 in a first drawing stage defined by at least one feed roller and at least one first draw roller, each of said at least one feed roller operated at a temperature less than about 100° C. and each of said at least one draw roller heated to a temperature greater than the temperature of said at least one feed roller and within the range of about 50 to about 150° C.;
(e) subsequently drawing the yarn at a second draw ratio of at least about 2.2 times that of the first draw ratio in a second drawing stage defined by said at least one first draw roller and at least one second draw roller, each of said at least one second draw roller heated to a temperature greater than said at least one first draw roller and within the range of about 100 to about 200° C.; and
(e) winding the drawn yarns, after optionally texturing the drawn yarns.
The invention process enables the production of poly(trimethylene terephthalate)-based carpet having the bulk and resiliency of nylon as well as the stain resistance and low static generation of polyester.
| 3
|
RELATED APPLICATION(S)
[0001] This application claims priority to U.S. Patent Application Ser. No. 61/131,572, entitled “System and Method for Measuring an Analyte in a Sample” filed on Jun. 9, 2009, which is hereby incorporated by reference in its entirety. This application is also related to the following co-pending patent applications: U.S. Patent Application Publication No. 2007/0235347, entitled “Systems and Methods for Discriminating Control Solution from a Physiological Sample” and filed on Mar. 31, 2006; U.S. Patent Application Publication No. 2009/0084687, entitled “Systems and Methods of Discriminating Control Solution From a Physiological Sample” and filed on Sep. 16, 2008, and U.S. patent application Ser. No. 12/349,017, entitled “System and Method For Measuring an Analyte in a Sample” filed on Jan. 6, 2009, each of which is hereby incorporated by reference in its entirety.
FIELD
[0002] The present disclosure relates to methods and systems for determining analyte concentration of a sample.
BACKGROUND
[0003] Analyte detection in physiological fluids, e.g. blood or blood derived products, is of ever increasing importance to today's society. Analyte detection assays find use in a variety of applications, including clinical laboratory testing, home testing, etc., where the results of such testing play a prominent role in diagnosis and management in a variety of disease conditions. Analytes of interest include glucose for diabetes management, cholesterol, and the like. In response to this growing importance of analyte detection, a variety of analyte detection protocols and devices for both clinical and home use have been developed.
[0004] One type of method that is employed for analyte detection is an electrochemical method. In such methods, an aqueous liquid sample is placed into a sample-receiving chamber in an electrochemical cell that includes two electrodes, e.g., a counter and working electrode. The analyte is allowed to react with a redox reagent to form an oxidizable (or reducible) substance in an amount corresponding to the analyte concentration. The quantity of the oxidizable (or reducible) substance present is then estimated electrochemically and related to the amount of analyte present in the initial sample.
[0005] Such systems are susceptible to various modes of inefficiency and/or error. For example, variations in temperatures can affect the results of the method. This is especially relevant when the method is carried out in an uncontrolled environment, as is often the case in home applications or in third world countries. Errors can also occur when the sample size is insufficient to get an accurate result. Partially filled test strips can potentially give an inaccurate result because the measured test currents are proportional to the area of the working electrode that is wetted with sample. Thus, partially filled test strips can under certain conditions provide a glucose concentration that is negatively biased. A user can have difficulty determining whether an electrode area of a test strip is completely covered by a sample. Many test strips, including the ones described herein, have a relatively small volume (<one microliter) making it difficult for a user to see and judge whether there is a small area of an electrode that is unwetted. This can especially be a problem for people with diabetes that often have poor visual acuity.
SUMMARY
[0006] Various aspects of a method of calculating an analyte concentration of a sample are provided. In one aspect the method accounts for temperature variation and includes applying a sample to a test strip and applying a first test voltage for a first time interval between a first electrode and a second electrode sufficient to oxidize a reduced mediator at the second electrode. A second test voltage can be applied for a second time interval between the first electrode and the second electrode that is also sufficient to oxidize the reduced mediator at the first electrode. A first glucose concentration can be calculated based on the test current values during the first time interval and the second time interval. Additionally, the test meter can measure a temperature value. Accordingly, a temperature corrected glucose concentration can be calculated based on the first glucose concentration and the temperature value.
[0007] In another aspect of a method of calculating an analyte concentration of a sample, the method is configured to determine whether a test strip is sufficiently filled with a sample. The method includes applying a first test voltage between a first electrode and a second electrode of a test strip. The first test voltage can have both an AC voltage component and a DC voltage component. The AC voltage component can be applied at a predetermined amount of time after the application of the first test voltage. The DC voltage component can have a magnitude sufficient to cause a limiting test current at the second electrode. Accordingly, a portion of the resulting test current from the AC voltage component can be processed into a capacitance value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0009] FIG. 1A is a perspective view of a test strip;
[0010] FIG. 1B is an exploded perspective view of the test strip of FIG. 1A ;
[0011] FIG. 1C is a perspective view of a distal portion of the test strip of FIG. 1A ;
[0012] FIG. 2 is a bottom plan view of the test strip of FIG. 1A ;
[0013] FIG. 3 is a side plan view of the test strip of FIG. 1A ;
[0014] FIG. 4A is a top plan view of the test strip of FIG. 1A ;
[0015] FIG. 4B is a partial side view of the distal portion of the test strip consistent with arrows 4 B- 4 B of FIG. 4A ;
[0016] FIG. 5 is a simplified schematic showing a test meter electrically interfacing with the test strip contact pads;
[0017] FIG. 6 shows a test voltage waveform in which the test meter applies a plurality of test voltages for prescribed time intervals;
[0018] FIG. 7 shows a test current transient generated with the test voltage waveform of FIG. 6 ;
[0019] FIG. 8 is a flow diagram showing an embodiment of a method of determining a glucose concentration;
[0020] FIG. 9 is a flow diagram showing an exemplary embodiment of a blood glucose algorithm and a hematocrit correction;
[0021] FIG. 10 is a chart showing a correlation between measured hematocrit levels using a reference method and measured hematocrit levels using the test strip of FIG. 1 ;
[0022] FIG. 11 is a bias plot showing a plurality of test strips that were tested with blood samples having a wide range of hematocrit levels;
[0023] FIG. 12 is a flow diagram showing an embodiment of a method of applying a temperature correction when a sample is blood;
[0024] FIG. 13 is a bias plot showing a plurality of test strips that were tested with blood samples having a wide range of hematocrit levels, a wide range of glucose levels, and a wide range of temperature levels without temperature correction;
[0025] FIG. 14 is a bias plot showing a plurality of test strips that were tested with blood samples having a wide range of hematocrit levels, a wide range of glucose levels, and a wide range of temperature levels with temperature correction;
[0026] FIG. 15 is a flow diagram showing an embodiment of a method of applying a temperature correction when a sample is control solution;
[0027] FIG. 16 is a bias plot showing a plurality of test strips that were tested with control solution samples having a wide range of glucose levels and a wide range of temperature levels without temperature correction;
[0028] FIG. 17 is a bias plot showing a plurality of test strips that were tested with control solution samples having a wide range of glucose levels and a wide range of temperature levels with temperature correction;
[0029] FIG. 18 is a flow diagram depicting an embodiment of a method of identifying system errors;
[0030] FIG. 19 is a chart showing a correlation of capacitance and bias to a reference glucose measurement (YSI, Yellow Springs Instrument) where capacitance values were measured for blood samples during the third test voltage of FIG. 6 ;
[0031] FIG. 20 is a chart showing a correlation of capacitance and bias to a reference glucose measurement (YSI, Yellow Springs Instrument) where capacitance values were measured for blood samples during the second test voltage of FIG. 6 (e.g., after approximately 1.3 seconds);
[0032] FIG. 21 is a chart showing a correlation of capacitance and bias to a reference glucose measurement (YSI, Yellow Springs Instrument) where capacitance values were measured for control solution samples during the second test voltage of FIG. 6 (e.g., after approximately 1.3 seconds);
[0033] FIG. 22 shows a test current transient of the second test time interval when a user performs a double dose (solid line) and does not perform a double dose (dotted line);
[0034] FIG. 23 shows a test current transient of the second test time interval when a late start error occurs (solid line) and does not occur (dotted line) with the test meter;
[0035] FIG. 24 shows a test current transient of the third test time interval for a test strip having a high resistance track (squares) and a low resistance track (triangles);
[0036] FIG. 25 is a chart showing a plurality of ratio values indicating that a high resistance test strip lot can be distinguished from a low resistance test strip lot;
[0037] FIG. 26 shows a plurality of test current transients for a test strip lot having leakage between a spacer and the first electrode (squares) and for test strip lots having a sufficiently low amount of leakage (circles and triangles); and
[0038] FIG. 27 is a chart showing a plurality of ratio values for identifying leakage of liquid for test strip lots prepared with different manufacturing conditions.
DETAILED DESCRIPTION
[0039] Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices, systems, and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.
[0040] The subject systems and methods are suitable for use in the determination of a wide variety of analytes in a wide variety of samples, and are particularly suited for use in the determination of analytes in whole blood, plasma, serum, interstitial fluid, or derivatives thereof. In an exemplary embodiment, a glucose test system based on a thin-layer cell design with opposing electrodes and tri-pulse electrochemical detection that is fast (e.g., about 5 second analysis time), requires a small sample (e.g., about 0.4 μL), and can provide improved reliability and accuracy of blood glucose measurements. In the reaction cell, glucose in the sample can be oxidized to gluconolactone using glucose dehydrogenase and an electrochemically active mediator can be used to shuttle electrons from the enzyme to a palladium working electrode. A potentiostat can be utilized to apply a tri-pulse potential waveform to the working and counter electrodes, resulting in test current transients used to calculate the glucose concentration. Further, additional information gained from the test current transients may be used to discriminate between sample matrices and correct for variability in blood samples due to hematocrit, temperature variation, electrochemically active components, and identify possible system errors.
[0041] The subject methods can be used, in principle, with any type of electrochemical cell having spaced apart first and second electrodes and a reagent layer. For example, an electrochemical cell can be in the form of a test strip. In one aspect, the test strip may include two opposing electrodes separated by a thin spacer for defining a sample-receiving chamber or zone in which a reagent layer is located. One skilled in the art will appreciate that other types of test strips, including, for example, test strips with co-planar electrodes may also be used with the methods described herein.
[0042] FIGS. 1A to 4B show various views of an exemplary test strip 62 suitable for use with the methods and systems described herein. In an exemplary embodiment, a test strip 62 is provided which includes an elongate body extending from a distal end 80 to a proximal end 82 , and having lateral edges 56 , 58 , as illustrated in FIG. 1A . As shown in FIG. 1B , the test strip 62 also includes a first electrode layer 66 , a second electrode layer 64 , and a spacer 60 sandwiched in between the two electrode layers 64 and 66 . The first electrode layer 66 can include a first electrode 166 , a first connection track 76 , and a first contact pad 67 , where the first connection track 76 electrically connects the first electrode 166 to the first contact pad 67 , as shown in FIGS. 1B and 4B . Note that the first electrode 166 is a portion of the first electrode layer 66 that is immediately underneath the reagent layer 72 , as indicated by FIGS. 1B and 4B . Similarly, the second electrode layer 64 can include a second electrode 164 , a second connection track 78 , and a second contact pad 63 , where the second connection track 78 electrically connects the second electrode 164 with the second contact pad 63 , as shown in FIGS. 1B , 2 , and 4 B. Note that the second electrode 164 is a portion of the second electrode layer 64 that is above the reagent layer 72 , as indicated by FIG. 4B .
[0043] As shown, the sample-receiving chamber 61 is defined by the first electrode 166 , the second electrode 164 , and the spacer 60 near the distal end 80 of the test strip 62 , as shown in FIGS. 1B and 4B . The first electrode 166 and the second electrode 164 can define the bottom and the top of sample-receiving chamber 61 , respectively, as illustrated in FIG. 4B . A cutout area 68 of the spacer 60 can define the sidewalls of the sample-receiving chamber 61 , as illustrated in FIG. 4B . In one aspect, the sample-receiving chamber 61 can include ports 70 that provide a sample inlet and/or a vent, as shown in FIGS. 1A to 1C . For example, one of the ports can allow a fluid sample to ingress and the other port can allow air to egress.
[0044] In an exemplary embodiment, the sample-receiving chamber 61 can have a small volume. For example, the chamber 61 can have a volume in the range of from about 0.1 microliters to about 5 microliters, about 0.2 microliters to about 3 microliters, or, preferably, about 0.3 microliters to about 1 microliter. To provide the small sample volume, the cutout 68 can have an area ranging from about 0.01 cm 2 to about 0.2 cm 2 , about 0.02 cm 2 to about 0.15 cm 2 , or, preferably, about 0.03 cm 2 to about 0.08 cm 2 . In addition, first electrode 166 and second electrode 164 can be spaced apart in the range of about 1 micron to about 500 microns, preferably between about 10 microns and about 400 microns, and more preferably between about 40 microns and about 200 microns. The relatively close spacing of the electrodes can also allow redox cycling to occur, where oxidized mediator generated at first electrode 166 , can diffuse to second electrode 164 to become reduced, and subsequently diffuse back to first electrode 166 to become oxidized again. Those skilled in the art will appreciate that various such volumes, areas, and/or spacing of electrodes is within the spirit and scope of the present disclosure.
[0045] In one embodiment, the first electrode layer 66 and the second electrode layer 64 can be a conductive material formed from materials such as gold, palladium, carbon, silver, platinum, tin oxide, iridium, indium, or combinations thereof (e.g., indium doped tin oxide). In addition, the electrodes can be formed by disposing a conductive material onto an insulating sheet (not shown) by a sputtering, electroless plating, or a screen-printing process. In one exemplary embodiment, the first electrode layer 66 and the second electrode layer 64 can be made from sputtered palladium and sputtered gold, respectively. Suitable materials that can be employed as spacer 60 include a variety of insulating materials, such as, for example, plastics (e.g., PET, PETG, polyimide, polycarbonate, polystyrene), silicon, ceramic, glass, adhesives, and combinations thereof. In one embodiment, the spacer 60 may be in the form of a double sided adhesive coated on opposing sides of a polyester sheet where the adhesive may be pressure sensitive or heat activated. Those skilled in the art will appreciate that various other materials for the first electrode layer 66 , the second electrode layer 64 , and/or the spacer 60 are within the spirit and scope of the present disclosure.
[0046] Various mechanisms and/or processes can be utilized to dispose a reagent layer 72 within the sample-receiving chamber 61 . For example, the reagent layer 72 can be disposed within the sample-receiving chamber 61 using a process such as slot coating, dispensing from the end of a tube, ink jetting, and screen printing. In one embodiment, the reagent layer 72 can include at least a mediator and an enzyme and is deposited onto first electrode 166 . Examples of suitable mediators include ferricyanide, ferrocene, ferrocene derivatives, osmium bipyridyl complexes, and quinone derivatives. Examples of suitable enzymes include glucose oxidase, glucose dehydrogenase (GDH) using a pyrroloquinoline quinone (PQQ) co-factor, GDH using a nicotinamide adenine dinucleotide (NAD) co-factor, and GDH using a flavin adenine dinucleotide (FAD) co-factor [E.C.1.1.99.10]. The reagent layer 72 can be prepared from a formulation that contains 33 mM potassium citraconate, pH 6.8, 0.033% Pluronic P103, 0.017% Pluronic F87, 0.85 mM CaCl 2 , 30 mM sucrose, 286 μM PQQ, 15 mg/mL apo-GDH, and 0.6 M ferricyanide. Alternatively, the PQQ can be left out of the formulation and the apo-GDH can be replaced with FAD-GDH. Pluronics are a block copolymers based on ethylene oxide and propylene oxide, which can function as antifoaming agents and/or wetting agents.
[0047] The formulation can be applied at 570 μL/min using a 13 gauge needle poised about 150 μm above a palladium web moving at about 10 m/min. Alternatively, the concentration of the solids in the reagent can be increased by 50% and the flow rate can be reduced to 380 μL/min in order to maintain a constant reagent coating density. Before coating the palladium web with the enzyme formulation, it can be coated with 2-mercaptoethane sulfonic acid (MESA). A 95 μm thick spacer with a 1.2 mm wide channel cut in it can be laminated to the reagent layer and the palladium web at 70° C. Next, a MESA-coated gold web can be laminated to the other side of the spacer. The spacer can be made from PET coated on both sides with a thermoplastic such as Vitel, which is a linear saturated copolyester resin having a relatively high molecular weight. The resulting laminate can be cut such that the fill path of the sample-receiving chamber is about 3.5 mm long, thus giving a total volume of about 0.4 μL.
[0048] In one embodiment, the reagent layer 72 may have an area larger than the area of the first electrodes 166 . As a result a portion of the spacer 60 may overlap and touch the reagent layer 72 . The spacer 60 may be configured to form a liquid impermeable seal to the first electrode 166 even though a portion of the reagent layer 72 is between the spacer 60 and the first electrode 166 . The spacer 60 may intermingle or partially dissolve a portion of the reagent layer 72 to form a liquid impermeable bond to the first electrode 166 sufficient to define the electrode area for at least the total test time. Under certain circumstances where the reagent layer 72 is not sufficiently dry, the spacer 60 may not be able to form a liquid impermeable seal and, as a result, the liquid may seep between the spacer 60 and the first electrode 166 . Such a leakage event may cause an inaccurate glucose measurement to occur.
[0049] Either the first electrode 166 or the second electrode 164 can perform the function of a working electrode depending on the magnitude and/or polarity of the applied test voltage. The working electrode may measure a limiting test current that is proportional to the reduced mediator concentration. For example, if the current limiting species is a reduced mediator (e.g., ferrocyanide), then it can be oxidized at the first electrode 166 as long as the test voltage is sufficiently greater than the redox mediator potential with respect to the second electrode 164 . In such a situation, the first electrode 166 performs the function of the working electrode and the second electrode 164 performs the function of a counter/reference electrode. Note that one skilled in the art may refer to a counter/reference electrode simply as a reference electrode or a counter electrode. A limiting oxidation occurs when all reduced mediator has been depleted at the working electrode surface such that the measured oxidation current is proportional to the flux of reduced mediator diffusing from the bulk solution towards the working electrode surface. The term bulk solution refers to a portion of the solution sufficiently far away from the working electrode where the reduced mediator is not located within a depletion zone. It should be noted that unless otherwise stated for test strip 62 , all potentials applied by test meter 100 will hereinafter be stated with respect to second electrode 164 .
[0050] Similarly, if the test voltage is sufficiently less than the redox mediator potential, then the reduced mediator can be oxidized at the second electrode 164 as a limiting current. In such a situation, the second electrode 164 performs the function of the working electrode and the first electrode 166 performs the function of the counter/reference electrode.
[0051] Initially, performing an analysis can include introducing a quantity of a fluid sample into a sample-receiving chamber 61 via a port 70 . In one aspect, the port 70 and/or the sample-receiving chamber 61 can be configured such that capillary action causes the fluid sample to fill the sample-receiving chamber 61 . The first electrode 166 and/or second electrode 164 may be coated with a hydrophilic reagent to promote the capillarity of the sample-receiving chamber 61 . For example, thiol derivatized reagents having a hydrophilic moiety such as 2-mercaptoethane sulfonic acid may be coated onto the first electrode and/or the second electrode.
[0052] FIG. 5 provides a simplified schematic showing a test meter 100 interfacing with a first contact pad 67 a , 67 b and a second contact pad 63 . The second contact pad 63 can be used to establish an electrical connection to the test meter through a U-shaped notch 65 , as illustrated in FIG. 2 . In one embodiment, the test meter 100 may include a second electrode connector 101 , and a first electrode connectors ( 102 a , 102 b ), a test voltage unit 106 , a current measurement unit 107 , a processor 212 , a memory unit 210 , and a visual display 202 , as shown in FIG. 5 . The first contact pad 67 can include two prongs denoted as 67 a and 67 b . In one exemplary embodiment, the first electrode connectors 102 a and 102 b separately connect to prongs 67 a and 67 b , respectively. The second electrode connector 101 can connect to second contact pad 63 . The test meter 100 can measure the resistance or electrical continuity between the prongs 67 a and 67 b to determine whether the test strip 62 is electrically connected to the test meter 100 . One skilled in the art will appreciate that the test meter 100 can use a variety of sensors and circuits to determine when the test strip 62 is properly positioned with respect to the test meter 100 .
[0053] In one embodiment, the test meter 100 can apply a test voltage and/or a current between the first contact pad 67 and the second contact pad 63 . Once the test meter 100 recognizes that the strip 62 has been inserted, the test meter 100 turns on and initiates a fluid detection mode. In one embodiment, the fluid detection mode causes test meter 100 to apply a constant current of about 1 microampere between the first electrode 166 and the second electrode 164 . Because the test strip 62 is initially dry, the test meter 100 measures a relatively large voltage, which can be limited by the analog-to-digital converter (A/D) within test meter 100 . When the fluid sample bridges the gap between the first electrode 166 and the second electrode 164 during the dosing process, the test meter 100 will measure a decrease in measured voltage that is below a predetermined threshold causing test meter 100 to automatically initiate the glucose test.
[0054] In one embodiment, the test meter 100 can perform a glucose test by applying a plurality of test voltages for prescribed intervals, as shown in FIG. 6 . The plurality of test voltages may include a first test voltage V 1 for a first time interval t 1 , a second test voltage V 2 for a second time interval t 2 , and a third test voltage V 3 for a third time interval t 3 . A glucose test time interval t G represents an amount of time to perform the glucose test (but not necessarily all the calculations associated with the glucose test). Glucose test time interval t G can range from about 1 second to about 5 seconds. Further, as illustrated in FIG. 6 , the second test voltage V 2 can include a constant (DC) test voltage component and a superimposed alternating (AC), or oscillating, test voltage component. The superimposed alternating test voltage component can be applied for a time interval indicated by t cap . The inset of FIG. 6 magnifies the high frequency AC component.
[0055] The plurality of test current values measured during any of the time intervals may be performed at a frequency ranging from about 1 measurement per nanosecond to about one measurement per 100 milliseconds. While an embodiment using three test voltages in a serial manner is described, one skilled in the art will appreciate that the glucose test can include different numbers of open-circuit and test voltages. For example, as an alternative embodiment, the glucose test could include an open-circuit for a first time interval, a second test voltage for a second time interval, and a third test voltage for a third time interval. One skilled in the art will appreciate that names “first,” “second,” and “third” are chosen for convenience and do not necessarily reflect the order in which the test voltages are applied. For instance, an embodiment can have a potential waveform where the third test voltage can be applied before the application of the first and second test voltage.
[0056] Once the glucose assay has been initiated, the test meter 100 may apply a first test voltage V 1 (e.g., −20 mV in FIG. 6 ) for a first time interval t 1 (e.g., 1 second in FIG. 6 ). The first time interval t 1 can range from about 0.1 seconds to about 3 seconds and preferably range from about 0.2 seconds to about 2 seconds, and most preferably range from about 0.3 seconds to about 1 seconds.
[0057] The first time interval t 1 may be sufficiently long so that the sample-receiving chamber 61 can fully fill with sample and also so that the reagent layer 72 can at least partially dissolve or solvate. In one aspect, the first test voltage V 1 may be a value relatively close to the redox potential of the mediator so that a relatively small amount of a reduction or oxidation current is measured. FIG. 7 shows that a relatively small amount of current is observed during the first time interval t 1 compared to the second and third time intervals t 2 and t 3 . For example, when using ferricyanide and/or ferrocyanide as the mediator, the first test voltage V 1 can range from about −100 mV to about −1 mV, preferably range from about −50 mV to about −5 mV, and most preferably range from about −30 mV to about −10 mV.
[0058] After applying the first test voltage V 1 , the test meter 100 applies a second test voltage V 2 between first electrode 166 and second electrode 164 (e.g., −0.3 Volts in FIG. 6 ), for a second time interval t 2 (e.g., about 3 seconds in FIG. 6 ). The second test voltage V 2 may be a value sufficiently negative of the mediator redox potential so that a limiting oxidation current is measured at the second electrode 164 . For example, when using ferricyanide and/or ferrocyanide as the mediator, the second test voltage V 2 can range from about −600 mV to about zero mV, preferably range from about −600 mV to about −100 mV, and more preferably be about −300 mV.
[0059] The second time interval t 2 should be sufficiently long so that the rate of generation of reduced mediator (e.g., ferrocyanide) can be monitored based on the magnitude of a limiting oxidation current. Reduced mediator is generated by enzymatic reactions with the reagent layer 72 . During the second time interval t 2 , a limiting amount of reduced mediator is oxidized at second electrode 164 and a non-limiting amount of oxidized mediator is reduced at first electrode 166 to form a concentration gradient between first electrode 166 and second electrode 164 .
[0060] In an exemplary embodiment, the second time interval t 2 should also be sufficiently long so that a sufficient amount of ferricyanide can be generated at the second electrode 164 . A sufficient amount of ferricyanide is required at the second electrode 164 so that a limiting current can be measured for oxidizing ferrocyanide at the first electrode 166 during the third test voltage V 3 . The second time interval t 2 may be less than about 60 seconds, and preferably can range from about 1 second to about 10 seconds, and more preferably range from about 2 seconds to about 5 seconds. Likewise, the time interval indicated as t cap in FIG. 6 may also last over a range of times, but in one exemplary embodiment it has a duration of about 20 milliseconds. In one exemplary embodiment, the superimposed alternating test voltage component is applied after about 0.3 seconds to about 0.4 seconds after the application of the second test voltage V 2 , and induces a sine wave having a frequency of about 109 Hz with an amplitude of about ±50 mV.
[0061] FIG. 7 shows a relatively small peak i pb at the beginning of the second time interval t 2 followed by a gradual increase of an absolute value of an oxidation current during the second time interval t 2 . The small peak i pb occurs due to an initial depletion of reduced mediator at about 1 second. The gradual absolute increase in oxidation current after the small peak i pb is caused by the generation of ferrocyanide by reagent layer 72 , which then diffuses to second electrode 164 .
[0062] After applying the second test voltage V 2 , the test meter 100 applies a third test voltage V 3 between the first electrode 166 and the second electrode 164 (e.g., about +0.3 Volts in FIG. 6 ) for a third time interval t 3 (e.g., 1 second in FIG. 6 ). The third test voltage V 3 may be a value sufficiently positive of the mediator redox potential so that a limiting oxidation current is measured at the first electrode 166 . For example, when using ferricyanide and/or ferrocyanide as the mediator, the third test voltage V 3 can range from about zero mV to about 600 mV, preferably range from about 100 mV to about 600 mV, and more preferably be about 300 mV.
[0063] The third time interval t 3 may be sufficiently long to monitor the diffusion of reduced mediator (e.g., ferrocyanide) near the first electrode 166 based on the magnitude of the oxidation current. During the third time interval t 3 , a limiting amount of reduced mediator is oxidized at first electrode 166 and a non-limiting amount of oxidized mediator is reduced at the second electrode 164 . The third time interval t 3 can range from about 0.1 seconds to about 5 seconds and preferably range from about 0.3 seconds to about 3 seconds, and more preferably range from about 0.5 seconds to about 2 seconds.
[0064] FIG. 7 shows a relatively large peak i pc at the beginning of the third time interval t 3 followed by a decrease to a steady-state current i ss value. In one embodiment, the second test voltage V 2 can have a first polarity and the third test voltage V 3 may have a second polarity that is opposite to the first polarity. In another embodiment, the second test voltage V 2 can be sufficiently negative of the mediator redox potential and the third test voltage V 3 can be sufficiently positive of the mediator redox potential. The third test voltage V 3 may be applied immediately after the second test voltage V 2 . However, one skilled in the art will appreciate that the magnitude and polarity of the second and third test voltages can be chosen depending on the manner in which analyte concentration is determined.
[0065] FIG. 8 illustrates one method of determining a glucose concentration by way of a flow diagram. A user can insert a test strip into a test meter and then apply a sample to the test strip. The test meter detects the presence of the sample and applies a test voltage, as shown in a step 1802 . In response to the test voltage, the test meter measures a test current, as shown in a step 1804 . A microprocessor of the test meter can then process the resulting test current values so that an accurate glucose measurement can be determined and to ensure that there are no system errors.
[0066] Another step in the method, as shown in step 1806 , can be performing a control solution (CS)/blood discrimination test. As indicated in step 1808 , if the CS/blood discrimination test determines that the sample is blood, then method 1800 moves to a series of steps that include: the application of a blood glucose algorithm 1810 , hematocrit correction 1812 , blood temperature correction 1814 , and error checks 1000 ; and if the CS/blood discrimination test determines that the sample is CS (i.e., not blood), then method 1800 moves to a series of steps that include: the application of a CS glucose algorithm 1824 , CS temperature correction 1826 , and error checks 1000 . After performing the error checks 1000 , step 1818 can be performed to determine if there are any errors. If there are no errors, then the test meter outputs a glucose concentration, as shown in a step 1820 , but if there are errors, then the test outputs an error message, as shown in a step 1822 .
Control Solution (CS)/Blood Discrimination Test
[0067] The CS/blood discrimination test 1806 can include a first reference value and a second reference value. The first reference value can be based on current values during the first time interval t 1 and the second reference value can be based on current values during both the second time interval t 2 and the third time interval t 3 . In one embodiment the first reference value can be obtained by performing a summation of the current values obtained during the first time current transient when using the test voltage waveform of FIG. 6 . By way of non-limiting example, a first reference value i sum can be represented by Equation 1:
[0000]
i
sum
=
∑
t
=
0.05
1
i
(
t
)
Eq
.
1
[0000] where the term i sum is the summation of current values and t is a time. The second reference value, sometimes referred to as the residual reaction index, can be obtained by a seventh ratio R 7 of current values during the second time interval and the third time interval, as shown in Eq. 2:
[0000]
R
7
=
abs
(
i
(
3.8
)
i
(
4.15
)
)
Eq
.
2
[0000] where abs represents an absolute function and 3.8 and 4.15 represent the time in seconds of the second and third time intervals, respectively, for this particular example. A discrimination criterion can be used to determine if the sample is either control solution or blood based on the first reference value of Eq. 1 and the second reference of Eq. 2. For example, the first reference value of Eq. 1 can be compared to a pre-determined threshold and the second reference value of Eq. 2 can be compared to a pre-determined threshold equation. The pre-determined threshold may be about 12 microamperes. The pre-determined threshold equation can be based on a function using the first reference value of Eq. 1. More specifically, as illustrated by Eq. 3, the pre-determined threshold equation can be:
[0000]
Z
1
*
(
i
sum
-
12
)
i
sum
Eq
.
3
[0000] where Z 1 can be a constant such as, for example, about 0.2. Thus, the CS/Blood discrimination test 1806 can identify a sample as blood if
[0000]
i
sum
>
12
and
if
R
7
<
Z
1
*
(
i
sum
-
12
)
i
sum
[0000] else the sample is a control solution.
Blood Glucose Algorithm
[0068] If the sample is identified as a blood sample, the blood glucose algorithm of step 1810 can be performed on the test current values. A first glucose concentration G 1 can be calculated using a glucose algorithm as shown in Equation 4:
[0000]
G
1
=
(
i
2
i
3
)
p
×
(
a
×
i
1
-
z
)
Eq
.
4
[0069] where i 1 is a first test current value, i 2 is a second test current value, i 3 is a third test current value, and the terms a, p, and z can be empirically derived calibration constants. All test current values (e.g., i 1 , i 2 , and i 3 ) in Equation 4 use the absolute value of the current. The first test current value i 1 and the second test current value i 2 can each be defined by an average or summation of one or more predetermined test current values that occur during the third time interval t 3 . The third test current value i 3 can be defined by an average or summation of one or more predetermined test current values that occur during the second time interval t 2 . One skilled in the art will appreciate that names “first,” “second,” and “third” are chosen for convenience and do not necessarily reflect the order in which the current values are calculated.
[0070] Equation 4 can be modified to provide an even more accurate glucose concentration. Instead of using a simple average of summation of test current values, the term i 1 can be defined to include peak current values i pb and i pc and the steady-state current i ss , as shown in Equation 5:
[0000]
i
1
=
i
2
{
i
pc
-
2
i
pb
+
i
ss
i
pc
+
i
ss
}
Eq
.
5
[0000] where a calculation of the steady-state current i ss can be based on a mathematical model, an extrapolation, an average at a predetermined time interval, a combination thereof, or any number of other ways for calculating a steady-state current. Some examples of methods for calculating i ss can be found in U.S. Pat. Nos. 5,942,102 and 6,413,410, each of which is hereby incorporated by reference in its entirety.
[0071] Alternatively, i ss may be estimated by multiplying the test current value at 5 seconds with a constant K 8 (e.g., 0.678). Thus, i ss ≃i(5)×K 8 ). The term K 8 can be estimated using Equation 6:
[0000]
iss
=
i
(
5
)
1
+
4
exp
(
-
4
π
2
Dx
0.975
L
2
)
Eq
.
6
[0000] where the number 0.975 is about the time in seconds after the third test voltage V 3 is applied that corresponds to i(5), which, assuming a linear variation over the time between about 0.95 seconds and 1 second, is the average current between 0.95 and 1 second, the term D is assumed to be about 5×10 −6 cm 2 /sec as a typical diffusion coefficient in blood, and the term L is assumed to be about 0.0095 cm, which represents the height of the spacer 60 .
[0072] Turning again to Eq. 5, i pc may be the test current value at 4.1 seconds, and i pb may be the test current value at 1.1 seconds, based on the test voltage and test current waveforms in FIGS. 6 and 7 .
[0073] Turning back to Eq. 4, i 2 can be defined to be
[0000]
i
2
=
∑
t
=
4.4
5
i
(
t
)
[0000] and i 3 can be defined to be
[0000]
i
3
=
∑
t
=
1.4
4
i
(
t
)
.
[0074] Equation 5 can be combined with Equation 4 to yield an equation for determining a more accurate glucose concentration that can compensate for the presence of endogenous and/or exogenous interferents in a blood sample, as shown in Equation 7:
[0000]
G
1
=
(
i
2
i
3
)
p
×
(
a
×
i
2
×
{
i
pc
-
2
i
pb
+
i
ss
i
pc
+
i
ss
}
-
z
)
Eq
.
7
[0000] where the first glucose concentration G 1 is the output of the blood glucose algorithm and the terms a, p, and z are constants that can be derived empirically.
CS Glucose Algorithm
[0075] If the sample is identified as a CS, the CS glucose algorithm of step 1824 can be performed on the test current values. A first glucose concentration G 1 for CS can be calculated using Equation 7 above, although the values for a, p, and z for CS can be different than those for blood.
Analyte Detection at Extreme Hematocrit Levels:
[0076] In addition to endogenous interferents, extreme hematocrit levels under certain circumstances can affect the accuracy of a glucose measurement. Thus, hematocrit correction 1812 can be applied by modifying G 1 to provide a second glucose concentration G 2 that is accurate even if the sample has an extreme hematocrit level (e.g., about 20% or about 60%).
[0077] Methods and systems of accurately measuring glucose concentrations in extreme hematocrit samples are provided herein. For example, FIG. 9 is a flow diagram depicting a method 2000 for calculating an accurate glucose concentration that accounts for blood samples having an extreme hematocrit level. A user can initiate a test by applying a sample to the test strip, as shown in a step 2001 . A first test voltage V 1 can be applied for a first time interval t 1 , as shown in a step 2002 . The resulting test current is then measured for the first time interval t 1 , as shown in a step 2004 . After the first time interval t 1 , the second test voltage V 2 is applied for a second time interval t 2 , as shown in a step 2006 . The resulting test current is then measured for the second time interval t 2 , as shown in a step 2008 . After the second time interval t 2 , the third test voltage V 3 is applied for a third time interval t 3 , as shown in a step 2010 . The resulting test current is then measured for the third time interval t 3 , as shown in a step 2012 .
[0078] Now that test current values have been collected by a test meter, a first glucose concentration G 1 can be calculated, as shown in a step 2014 . The first glucose concentration G 1 can be calculated using Equations 4 or 7. Next, a hematocrit level H can be calculated, as shown in a step 2016 .
[0079] The hematocrit level may be estimated using test current values acquired during the glucose test time interval t G . Alternatively, the hematocrit level H may be estimated using test current values acquired during the second time interval t 2 and the third time interval t 3 . In one embodiment, the hematocrit level H can be estimated using a hematocrit equation based upon the first glucose concentration G 1 and i 2 . An exemplary hematocrit equation is shown in Equation 8:
[0000] H=K 5 ln(| i 2 |)+ K 6 ln( G 1 )+ K 7 Eq. 8
[0080] where H is the hematocrit level, i 2 is at least one current value during the second time interval, K 5 is a fifth constant, K 6 is a sixth constant, and K 7 is a seventh constant. When GDH-PQQ is the enzyme, K 5 , K 6 , and K 7 may be about −76, 56, and 250, respectively. When FAD-GDH is the enzyme, K 5 , K 6 , and K 7 may be about −73.5, 58.8, and 213, respectively. FIG. 10 shows that the estimated hematocrit levels using Equation 8 has an approximately linear correlation with actual hematocrit levels measured with a reference method.
[0081] Once the hematocrit level H has been calculated in step 2016 , it is compared to a lower predetermined hematocrit level H L , as shown in a step 2018 . The lower predetermined hematocrit level H L may be about 30%. If the hematocrit level H is less than lower predetermined hematocrit level H L , then the first glucose concentration G 1 is compared to an upper predetermined glucose concentration G U , as shown in a step 2020 . The upper predetermined glucose concentration G U may be about 300 mg/dL. If the hematocrit level H is not less than lower predetermined hematocrit level H L , then the hematocrit level H is compared to an upper predetermined hematocrit level H U , as shown in a step 2022 . The upper predetermined hematocrit level H U may be about 50%. If the hematocrit level H is greater than H U , then the first glucose concentration G 1 is compared to a lower predetermined glucose concentration G L , as shown in a step 2028 . The lower predetermined glucose concentration G L may be about 100 mg/dL. Steps 2018 and 2022 indicate that method 2000 will output first glucose concentration G 1 , as shown in a step 2034 , if the hematocrit level H is not less than H L and not greater than H U .
[0082] A first function can be used to calculate a correction value Corr, as shown in a step 2024 , if the first glucose concentration G 1 is less than the upper predetermined glucose concentration G U . The first function may be in the form of Equation 9:
[0000] Corr= K 1 ( H L −H ) G 1 Eq. 9
[0083] where K 1 is a first constant and H L is the lower predetermined hematocrit level. In one embodiment K 1 and H L may be about −0.004 and about 30%, respectively.
[0084] However, if the first glucose concentration G 1 is not less than the upper predetermined glucose concentration G U , then the second function can be used to calculate the correction value Corr, as shown in a step 2026 . The second function may be in the form of Equation 10:
[0000] Corr= K 2 ( H L −H )( G max −G 1 ) Eq. 10
[0000] where K 2 is a second constant and G max is a predetermined maximum glucose concentration. In one embodiment K 2 and G max may be about −0.004 and about 600 mg/dL, respectively. The correction value Corr for Equations 9 and 10 may be restricted to a range of about −5 to about zero. Thus, if Corr is less than −5, then Corr is set to −5 and if Corr is greater than zero, then Corr is set to zero.
[0085] A third function can be used to calculate a correction value Corr, as shown in a step 2030 , if the first glucose concentration G 1 is less than lower predetermined glucose concentration G L . The third function may be in the form of Equation 11:
[0000] Corr=0 Eq. 11
[0000] however, if the first glucose concentration G 1 is not less than the lower predetermined glucose concentration G L , then the fourth function can be used to calculate the correction value Corr, as shown in a step 2032 . The fourth function may be in the form of Equation 12:
[0000] Corr= K 4 ( H−H U )( G 1 −G L ) Eq. 12
[0000] where K 4 is a fourth constant, which may be about 0.011. The correction value Corr for Equation 12 may be restricted to a range of about zero to about six. Thus, if Corr is less than zero, then Corr is set to zero and if Corr is greater than six, then Corr is set to six.
[0086] After calculating Corr with the first function in step 2024 , the first glucose concentration is compared to 100 mg/dL in a step 2036 . If the first glucose concentration is less than 100 mg/dL, then the second glucose concentration G 2 is calculated using a first correction equation, as shown in a step 2038 . Note that the 100 mg/dL represents a glucose threshold and should not be construed as a limiting number. In one embodiment, the glucose threshold may range from about 70 mg/dL to about 100 mg/dL. The first correction equation may be in the form of Equation 13:
[0000] G 2 =G 1 +Corr. Eq. 13
[0000] If the first glucose concentration G 1 is not less than 100 mg/dL based on step 2036 , then the second glucose concentration G 2 is calculated using a second correction equation, as shown in a step 2040 . The second correction equation may be in the form of Equation 14:
[0000]
G
2
=
G
1
(
1
+
Corr
100
)
.
Eq
.
14
[0000] After the second glucose concentration G 2 is calculated in either steps 2038 or 2040 , it is outputted as a glucose reading in a step 2042 .
[0087] After calculating Corr in step 2026 , 2030 , or 2032 , the second glucose concentration G 2 can be calculated using Equation 14, as shown in step 2040 . When Corr equals zero (as for the third function), the second glucose concentration G 2 equals the first glucose concentration G 1 , which can then be outputted as a glucose reading in step 2042 .
[0088] The method 2000 for calculating accurate glucose concentrations in blood samples having extreme hematocrit levels was verified using blood from several donors. FIG. 11 shows a bias plot for a plurality of test strips that were tested with blood samples having a wide range of hematocrit levels and glucose concentrations. More specifically, FIG. 11 shows the effect of whole blood samples having a wide range of hematocrit on the accuracy and precision of the new test system. As shown, the bias of the sensor response with respect to the YSI 2700 (Yellow Springs Instruments, Yellow Springs, Ohio) is plotted against the plasma glucose concentration. The data were obtained with 3 batches of sensors and 4 blood donors. The hematocrit was adjusted to 20% (squares), 37-45% (circles) or 60% (triangles) prior to spiking the samples with glucose. These data suggest that the thin layer cell and tri-pulse approach for electrochemical measurement offers the opportunity for improved analytical performance with blood glucose test systems. Thus, the use of the correction value Corr, which depends on the hematocrit level H and the first glucose concentration G 1 , allows for the determination of a more accurate second glucose concentration G 2 even if the blood sample has an extreme hematocrit level.
Blood Temperature Correction:
[0089] Turning back to FIG. 8 , blood temperature correction 1814 can be applied to the test current values to provide a glucose concentration with an improved accuracy because of a reduced effect from temperature. A method for calculating a temperature corrected glucose concentration can include measuring a temperature value and calculating a second correction value Corr 2 . The second correction value Corr 2 can be based on a temperature value and either first glucose concentration G 1 or second glucose concentration G 2 glucose concentration, both of which as described previously do not include a correction for temperature. Accordingly, the second correction value Corr 2 can then be used to correct the glucose concentration G 1 or G 2 for temperature.
[0090] FIG. 12 is a flow diagram depicting an embodiment of the method 1814 of applying a blood temperature correction. Initially, a glucose concentration uncorrected for temperature can be obtained such as first glucose concentration G 1 from step 1810 or a second glucose concentration G 2 from step 1812 . While a blood temperature correction can be applied to either G 1 or G 2 , for simplicity the blood temperature correction will be described using G 2 .
[0091] As shown in a step 1910 of the method 1814 , a temperature value can be measured. The temperature can be measured using a thermistor or other temperature reading device that is incorporated into a test meter, or by way of any number of other mechanisms or means. Subsequently, a determination can be performed to determine whether the temperature value T is greater than a first temperature threshold T 1 . As illustrated in FIG. 12 , the temperature threshold T 1 is about 15° C. If the temperature value T is greater than 15° C., then a first temperature function can be applied to determine the second correction value Corr 2 , as shown in a step 1914 . If the temperature value T is not greater than 15° C., then a second temperature function can be applied to determine the second correction value Corr 2 , as shown in a step 1916 .
[0092] The first temperature function for calculating the second correction value Corr 2 can be in the form of Equation 15:
[0000] Corr 2 =−K 9 ( T−T RT )+ K 10 ×G 2 ( T−T RT ) Eq. 15
[0000] where Corr 2 is the correction value, K 9 is a ninth constant (e.g., 0.57 for GDH-PQQ and 0.89 for FAD-GDH), T is a temperature value, T RT is a room temperature value (e.g., 22° C.), K 10 is a tenth constant (e.g., 0.00023 for GDH-PQQ and 0.00077 for FAD-GDH), and G 2 is the second glucose concentration. When T is about equal to T RT , Corr 2 is about zero. In some instances, the first temperature function can be configured to have essentially no correction at room temperature such that variation can be reduced under routine ambient conditions. The second temperature function for calculating the second correction value Corr 2 can be in the form of Equation 16:
[0000] Corr 2 =−K 11 ( T−T RT )+ K 12 ×G 2 ( T−T RT )− K 13 ×G 2 ( T−T 1 )+ K 14 ×G 2 ( T−T 1 ) Eq. 16
[0000] where Corr 2 is the correction value, K 11 is an eleventh constant (e.g., 0.57 for GDH-PQQ and 0.89 for FAD-GDH), T is a temperature value, T RT is a room temperature value, K 12 is a twelfth constant (e.g., 0.00023 for GDH-PQQ and 0.00077 for FAD-GDH), G 1 is a first glucose concentration, K 13 is a thirteenth constant (e.g., 0.63 for GDH-PQQ and 1.65 for FAD-GDH), T 1 is a first temperature threshold, and K 14 is a fourteenth constant (e.g., 0.0038 for GDH-PQQ and 0.0029 for FAD-GDH).
[0093] After the Corr 2 is calculated using either step 1914 or 1916 , a couple of truncation functions can be performed to ensure that Corr 2 is constrained to a pre-determined range, thereby mitigating the risk of an outlier. In one embodiment Corr 2 can be limited to have a range of −10 to +10 by using a step 1918 and/or a step 1922 . In the step 1918 , a determination can be performed to determine whether Corr 2 is greater than 10. If Corr 2 is greater than 10, the Corr 2 is set to 10, as shown in a step 1920 . If Corr 2 is not greater than 10, then a determination is performed to determine whether Corr 2 is less than −10, as shown in a step 1922 . Corr 2 can be set to −10 if Corr 2 is less than −10, as shown in a step 1924 . If Corr 2 is a value already in between −10 and +10, then there generally is no need for truncation.
[0094] Once Corr 2 is determined, a temperature corrected glucose concentration can be calculated using either a step 1928 or a step 1930 . In a step 1926 , a determination can be performed to determine whether the glucose concentration uncorrected for temperature (e.g., G 2 ) is less than 100 mg/dL. If G 2 is less than 100 mg/dL, then an Equation 17 can be used to calculate the temperature corrected glucose concentration G 3 by adding the correction value Corr 2 to the second glucose concentration G 2 :
[0000] G 3 =G 2 +Corr 2 . Eq. 17
[0095] If G 2 is not less than 100 mg/dL, then an Equation 18 can be used to calculate the temperature corrected glucose concentration G 3 by dividing Corr 2 by one hundred, adding one; and then multiplying by the second glucose concentration G 2 :
[0000] G 3 =G 2 [1+0.01×Corr 2 ]. Eq. 18
[0000] Once a third glucose concentration is determined that has been corrected for the effects of temperature, the third glucose concentration can be outputted, as shown in a step 1932 .
[0096] The method 1814 for blood temperature correction was verified using blood in a glove box over a temperature range of about 5° C. to 45° C. The blood samples had a hematocrit range of about 20-50% hematocrit and a glucose range of about 20-600 mg/dL equivalent plasma glucose concentration. The glove box was an enclosed chamber that could hold a pre-determined constant temperature. The glove portion of the glove box allowed a tester outside of the glove box to perform a glucose test inside the glove box. The tester inserted test strips into a test meter and dose sampled in an environment having both a controlled temperature and relative humidity (RH). The RH was maintained at about 60% in order to keep evaporation of the sample droplets at a relatively low level during the test. Generally the RH should not be too high to prevent condensation from occurring on the test meter. The blood was equilibrated to 37° C. outside the glove box, pipetted onto parafilm, rapidly moved into the glove box, and applied to the strips. This particular method allowed for the simulation of dosing capillary blood off a finger. FIG. 13 shows that temperature has a substantial bias on the blood results when there is no temperature compensation function in the test meters because only about 83.4% of biases were within 15% or 15 mg/dL of the reference glucose value. In contrast, as seen in FIG. 14 , there is much less bias on the blood results when there is a temperature compensation in the test meters because far less biases percentage-wise were located outside of the 15% or 15 mg/dL range of the reference glucose value when compared to the results of FIG. 13 .
Control Solution Temperature Correction:
[0097] FIG. 15 is a flow diagram depicting an embodiment of the method 1826 of applying a CS temperature correction. The CS temperature correction is similar to the blood temperature correction except that the temperature function for calculating Corr 2 is different.
[0098] Initially, a glucose concentration uncorrected for temperature can be obtained such as first glucose concentration G 1 from step 1824 . Next, a temperature value can be measured, as shown in a step 1910 . A third temperature function can be applied to determine the second correction value Corr 2 for CS, as shown in a step 1934 . The third temperature function for calculating the second correction value Corr 2 can be in the form of Equation 19:
[0000] Corr 2 =−K 15 ( T−T RT )− K 16 ×G 2 ( T−T RT ) Eq. 19
[0000] where K 15 is a fifteenth constant (e.g., 0.27 for GDH-PQQ and 0.275 for FAD-GDH), T is a temperature value, T RT is a room temperature value (e.g., 22° C.), K 16 is a sixteenth constant (e.g., 0.0011 for GDH-PQQ and 0.00014 for FAD-GDH), and G 2 is the second glucose concentration.
[0099] After the Corr 2 is calculated using step 1934 , a couple of truncation functions can be performed to ensure that Corr 2 is constrained to a pre-determined range. In one embodiment Corr 2 can be limited to have a range of −10 to +10 by using a step 1918 and/or a step 1922 , as shown in FIG. 20 . In step 1918 , a determination can be performed to determine whether Corr 2 is greater than 10. If Corr 2 is greater than 10, the Corr 2 can be set to 10, as shown in a step 1920 . If Corr 2 is not greater than 10, then a determination can be performed to determine whether Corr 2 is less than −10, as shown in a step 1922 . Corr 2 can be set to −10 if Corr 2 is less than −10, as shown in a step 1924 .
[0100] Once Corr 2 is determined, a temperature corrected glucose concentration for CS can be calculated using either a step 1928 or a step 1930 . In a step 1926 , a determination can be performed to determine whether the glucose concentration uncorrected for temperature (e.g., G 1 ) is less than 100 mg/dL. If G 1 is less than 100 mg/dL, then third glucose concentration G 3 can be calculated by adding G 1 +Corr 2 , as shown in step 1928 . If G 1 is not less than 100 mg/dL, then third glucose concentration G 3 can be calculated by dividing Corr 2 by one hundred, adding one, and then multiplying by the second glucose concentration to give a temperature corrected concentration, as shown in step 1930 . Once a third glucose concentration for CS is determined that is corrected for the effects of temperature, the third glucose concentration can be outputted, as shown in a step 1932 , to either the next step in method 1800 or to error checks 1000 .
[0101] The method 1826 for CS temperature correction was verified in a glove box over a temperature range of about 5° C. to 45° C. The relative humidity (RH) was maintained at about 60%. FIG. 16 shows that temperature has a substantial bias on the CS results when there is no temperature compensation function in the meters because a fair amount of the results fall outside of 15% or 15 mg/dL of the reference glucose value. In contrast, as seen in FIG. 17 , there is much less bias on the blood results when there is a temperature compensation in the test meters because none of the results were located outside of the 15% or 15 mg/dL range of the glucose value.
Identifying System Errors:
[0102] Various embodiments of a method for identifying various system errors, which may include user errors when performing a test, test meter errors, and defective test strips, are also provided. The system can be configured to identify a test utilizing a partial fill or double-fill of a sample chamber. Also, the system can be configured to identify those situation where the sample may be leaking from the sample chamber thereby compromising the integrity of the testing and/or those situations where some portion of system (e.g., the test strip) is damaged.
[0103] For example, FIG. 18 is a flow diagram depicting an exemplary embodiment of a method 1000 of identifying system errors in performing an analyte measurement. As shown, a user can initiate a test by applying a sample to a test strip, as shown in a step 1002 . After the sample has been dosed, the test meter applies a first test voltage V 1 for a first time interval t 1 , as shown in a step 1004 a . A resulting test current is then measured for the first time interval t 1 , as shown in a step 1005 a . During the first time interval t 1 , the test meter can perform a double dose check 1006 a and a maximum current check 1012 a . If either the double dose check 1006 a or maximum current check 1012 a fails, then the test meter will display an error message, as shown in a step 1028 . If the double dose check 1006 a and maximum current check 1012 a both pass, then the test meter can apply a second test voltage V 2 for a second time interval t 2 , as shown in a step 1004 b.
[0104] A resulting test current is measured for the second time interval t 2 , as shown in a step 1005 b . During the application of the second test voltage V 2 , the test meter can perform a sufficient volume check 1030 , a double dose check 1006 b , a maximum current check 1012 b , and a minimum current check 1014 b . If one of the checks 1030 , 1006 b , 1012 b , or 1014 b fails, then the test meter will display an error message, as shown in step 1028 . If all of the checks 1030 , 1006 b , 1012 b , and 1014 b pass, then the test meter will apply a third test voltage V 3 , as shown in a step 1004 c.
[0105] A resulting test current is measured for the third time interval t 3 , as shown in a step 1005 c . During the application of the third test voltage V 3 , the test meter can perform a double dose check 1006 c , maximum current check 1012 c , a minimum current check 1014 c , a high resistance check 1022 c , and a sample leakage check 1024 c . If all of the checks 1006 c , 1012 c , 1014 c , 1022 c , and 1024 c pass, then the test meter will display a glucose concentration, as shown in a step 1026 . If one of the checks 1006 c , 1012 c , 1014 c , 1022 c , and 1024 c fails, then the test meter will display an error message, as shown in step 1028 . The following will describe the system checks and how errors can be identified using such system checks.
Sufficient Volume Check
[0106] In one embodiment for performing a sufficient volume check, a capacitance measurement is used. The capacitance measurement can measure essentially an ionic double-layer capacitance resulting from the formation of ionic layers at the electrode-liquid interface. A magnitude of the capacitance can be proportional to the area of an electrode coated with sample. Once the magnitude of the capacitance is measured, if the value is greater than a threshold and thus the test strip has a sufficient volume of liquid for an accurate measurement, a glucose concentration can be outputted, but if the value is not greater than a threshold and thus the test strip has an insufficient volume of liquid for an accurate measurement, then an error message can be outputted.
[0107] By way of non-limiting example, methods and mechanisms for performing capacitance measurements on test strips can be found in U.S. Pat. Nos. 7,195,704 and 7,199,594, each of which is hereby incorporated by reference in its entirety. In one method for measuring capacitance, a test voltage having a constant component and an oscillating component is applied to the test strip. In such an instance, the resulting test current can be mathematically processed, as described in further detail below, to determine a capacitance value.
[0108] Generally, when a limiting test current occurs at a working electrode having a well-defined area (i.e., an area not changing during the capacitance measurement), the most accurate and precise capacitance measurements in an electrochemical test strip can be performed. A well-defined electrode area that does not change with time can occur when there is a tight seal between the electrode and the spacer. The test current is relatively constant when the current is not changing rapidly due either to glucose oxidation or electrochemical decay. Alternatively, any period of time when an increase in signal, which would be seen due to glucose oxidation, is effectively balanced by a decrease in signal, which accompanies electrochemical decay, can also be an appropriate time interval for measuring capacitance.
[0109] An area of first electrode 166 can potentially change with time after dosing with the sample if the sample seeps in between the spacer 60 and the first electrode 166 . In an embodiment of a test strip, reagent layer 72 can be have an area larger than the cutout area 68 that causes a portion of the reagent layer 72 to be in between the spacer 60 and the first electrode layer 66 . Under certain circumstances, interposing a portion of the reagent layer 72 in between the spacer 60 and the first electrode layer 66 can allow the wetted electrode area to increase during a test. As a result, a leakage can occur during a test that causes the area of the first electrode to increase with time, which in turn can distort a capacitance measurement.
[0110] In contrast, an area of second electrode 164 can be more stable with time compared to the first electrode 166 because there is no reagent layer in between the second electrode 164 and the spacer 60 . Thus, the sample is less likely to seep in between the spacer 60 and the second electrode 164 . A capacitance measurement that uses a limiting test current at the second electrode 164 can thus be more precise because the area does not change during the test.
[0111] Referring back to FIG. 6 , once liquid is detected in the test strip, a first test voltage V 1 (e.g., −20 mV) can be applied between the electrodes for about 1 second to monitor the fill behavior of the liquid and to distinguish between control solution and blood. In Equation 1, the test currents are used from about 0.05 to 1 second. This first test voltage V 1 can be relatively low (i.e., the test voltage is similar in magnitude to the redox potential of the mediator) such that the distribution of ferrocyanide in the cell is disturbed as little as possible by the electrochemical reactions occurring at the first and second electrodes.
[0112] A second test voltage V 2 (e.g., −300 mV) having a larger absolute magnitude can be applied after the first test voltage V 1 such that a limiting current can be measured at the second electrode 164 . The second test voltage V 2 can include an AC voltage component and a DC voltage component. The AC voltage component can be applied at a predetermined amount of time after the application of the second test voltage V 2 , and further, can be a sine wave having a frequency of about 109 Hertz and an amplitude of about ±50 millivolts. In a preferred embodiment, the predetermined amount of time can range from about 0.3 seconds to about 0.4 seconds after the application of the second test voltage V 2 . Alternatively, the predetermined amount of time can be a time where a test current transient as a function of time has a slope of about zero. In another embodiment, the predetermined amount of time can be a time required for a peak current value (e.g., i pb ) to decay by about 50%. As for the DC voltage, it can be applied at a beginning of the first test voltage. The DC voltage component can have a magnitude sufficient to cause a limiting test current at the second electrode such as, for example, about −0.3 volts with respect to the second electrode.
[0113] Consistent with FIG. 4B , the reagent layer 72 is not coated onto the second electrode 164 , which causes the magnitude of the absolute peak current i pb to be relatively low compared to the magnitude of the absolute peak current i pc . The reagent layer 72 can be configured to generate a reduced mediator in a presence of an analyte, and the amount of the reduced mediator proximate to first electrode can contribute to the relatively high absolute peak current i pc . In one embodiment at least the enzyme portion of the reagent layer 72 can be configured to not substantially diffuse from the first electrode to the second electrode when a sample is introduced into the test strip.
[0114] The test currents after i pb tends to settle to a flat region at approximately 1.3 seconds, and then the current increases again as the reduced mediator generated at the first electrode 166 , which can be coated with the reagent layer 72 , diffuses to the second electrode 164 , which is not coated with the reagent layer 72 . Generally, the glucose algorithm requires test current values both before and after the test interval of about 1.3 to about 1.4 seconds. For example, i pb is measured at 1.1 seconds in Equation 7 and test currents are measured at 1.4 seconds onwards for
[0000]
i
3
=
∑
t
=
1.4
4
i
(
t
)
.
[0115] In one embodiment, a capacitance measurement can be performed at a relatively flat region of the test current values, which can be performed at about 1.3 seconds to about 1.4 seconds. Generally, if the capacitance is measured before 1 second, then the capacitance measurement can interfere with the relatively low first test voltage V 1 that can be used in the CS/blood discrimination test 1806 . For example, an oscillating voltage component on the order of ±50 mV superimposed onto a −20 mV constant voltage component can cause significant perturbation of the measured test current. Not only does the oscillating voltage component interfere with the first test voltage V 1 , but it can also significantly perturb the test currents measured after 1.4 seconds, which in turn can interfere with the blood glucose algorithm 1810 . Following a great deal of testing and experimentation, it was finally determined that, surprisingly, measuring the capacitance at about 1.3 seconds to about 1.4 seconds resulted in accurate and precise measurements that did not interfere with the CS/blood discrimination test or the glucose algorithm.
[0116] After the second test voltage V 2 , the third test voltage V 3 (e.g., +300 mV) can be applied causing the test current to be measured at the first electrode 166 , which can be coated with the reagent layer 72 . The presence of a reagent layer on the first electrode can allow penetration of liquid between the spacer layer and the electrode layer, which can cause the electrode area to increase.
[0117] As illustrated in FIG. 6 , in an exemplary embodiment a 109 Hz AC test voltage (±50 mV peak-to-peak) can be applied for 2 cycles during the time interval t cap . The first cycle can be used as a conditioning pulse and the second cycle can be used to determine the capacitance. The capacitance estimate can be obtained by summing the test current over a portion of the alternating current (AC) wave, subtracting the direct current (DC) offset, and normalizing the result using the AC test voltage amplitude and the AC frequency. This calculation provides a measure of the capacitance of the strip, which is dominated by the strip sample chamber when it is filled with a sample.
[0118] In one embodiment the capacitance can be measured by summing the test current over one quarter of the AC wavelength on either side of the point in time where the input AC voltage crosses the DC offset, i.e. when the AC component of the input voltage is zero (the zero crossing point). A derivation of how this translates to a measure of the capacitance is described in further detail below. Equation 20 can show the test current magnitude as a function of time during the time interval t cap :
[0000] i ( t )= i o +st+I sin(ω t +φ) Eq. 20
[0000] where the terms i o +st represent the test current caused by the constant test voltage component. Generally, the DC current component is considered as changing linearly with time (due to the on-going glucose reaction generating ferrocyanide) and is thus represented by a constant i 0 , which is the DC current at time zero (the zero crossing point), and s, the slope of the DC current change with time. The AC current component is represented by I sin(ωt+φ), where I is the amplitude of the current wave, ω is its frequency, and φ is its phase shift relative to the input voltage wave. The term so can also be expressed as 2πf, where f is the frequency of the AC wave in Hertz. The term I can also be expressed as shown in Equation 21:
[0000]
I
=
V
Z
Eq
.
21
[0000] where V is the amplitude of the applied voltage signal and |Z| is the magnitude of the complex impedance. The term |Z| can also be expressed as shown in Equation 22:
[0000]
Z
=
R
1
+
tan
2
φ
=
R
1
+
ω
2
R
2
C
2
Eq
.
22
[0000] where R is the real part of the impedance and C is the capacitance.
[0119] Equation 20 can be integrated from one quarter wavelength before the zero crossing point to one quarter wavelength after the zero crossing point to yield Equation 23:
[0000]
∫
-
1
4
f
1
4
f
i
(
t
)
=
i
o
[
t
]
-
1
4
f
1
4
f
+
s
2
[
t
2
]
-
1
4
f
1
4
f
+
I
∫
-
1
4
f
1
4
f
sin
(
ω
t
+
φ
)
,
Eq
.
23
[0000] which can be simplified to Equation 24:
[0000]
∫
-
1
4
f
1
4
f
i
(
t
)
=
i
o
2
f
+
I
sin
φ
π
f
.
Eq
.
24
[0000] By substituting Eq. 21 into Eq. 20, then into Eq. 23, and then rearranging, Equation 25 results:
[0000]
C
=
1
2
V
(
∫
-
1
4
f
1
4
f
i
(
t
)
-
i
o
2
f
)
.
Eq
.
25
[0000] The integral term in Equation 25 can be approximated using a sum of currents shown in an Equation 26:
[0000]
∫
-
1
4
f
1
4
f
i
(
t
)
≈
1
n
∑
k
=
1
n
i
k
2
f
Eq
.
26
[0000] where the test currents i k are summed from one quarter wavelength before the zero crossing point to one quarter wavelength past the zero crossing point. Substituting Equation 26 into Equation 25 yields Equation 27:
[0000]
C
=
1
n
∑
k
=
1
n
i
k
-
i
o
4
Vf
,
Eq
.
27
[0000] in which the DC offset current i o can be obtained by averaging the test current over one full sine cycle around the zero crossing point.
[0120] In another embodiment, the capacitance measurements can be obtained by summing the currents not around the voltage zero crossing point, but rather around the maximum AC component of the current. Thus, in Equation 26, rather than sum a quarter wavelength on either side of the voltage zero crossing point, the test current can be summed a quarter wavelength around the current maximum. This is tantamount to assuming that the circuit element responding to the AC excitation is a pure capacitor, so φ is π/2. Thus, Equation 24 can be reduced to Equation 28:
[0000]
∫
-
1
4
f
1
4
f
i
(
t
)
=
i
o
2
f
+
I
π
f
.
Eq
.
28
[0000] This is a reasonable assumption in this case as the uncoated electrode is polarized such that the DC, or real, component of the current flowing is independent of the voltage applied over the range of voltages used in the AC excitation. Accordingly, the real part of the impedance responding to the AC excitation is infinite, implying a pure capacitive element. Equation 28 can then be used with Equation 25 to yield a simplified capacitance equation that does not require an integral approximation. The net result is that capacitance measurements when summing the currents not around the voltage crossing point, but rather around the maximum AC component of the current, were more precise.
[0121] In one exemplary embodiment the microprocessor of the test meter can have a heavy load with calculating the glucose concentration. In such an instance, because the capacitance data acquisition needs to be made part way through the test rather than at its beginning, it can be necessary to defer the processing of the capacitance measurement data until after the determination of the glucose concentration is completed. Thus, once the glucose measurement part of the test is completed, the capacitance can be calculated, and if the capacitance is below a pre-determined threshold, a partial fill error can be flagged.
[0122] Under certain circumstances the capacitance measurement can depend on the environmental temperature. To measure capacitance in an accurate and precise manner for determining electrode fill volumes, the effect of temperature can be reduced using a temperature correction for blood as shown in Equation 29:
[0000] Cap corr =Cap−1.9× T Eq. 29
[0000] where Cap corr is the temperature corrected capacitance value, Cap is capacitance, and T is temperature.
[0123] The effect of temperature can be removed using a temperature correction for CS as shown in Equation 30:
[0000] Cap corr =Cap−0.56× T. Eq. 30
[0000] The temperature-corrected capacitance values from Equations 29 and 30 can be used for identifying partially filled test strips.
[0124] As illustrated by Table 1 below, a different temperature-corrected capacitance threshold value will be required for blood and control solution. The threshold should generally be set four (4) standard deviation units below the mean. Statistically this equates to a 99.994% certainty that no complete fill will be identified as a partial fill. The temperature-corrected capacitance threshold value for blood will be about 450 nF, and the corresponding value for control solution will be about 560 nF. These values can be programmed into a memory portion of the test meters. In an alternative embodiment, the threshold value can be adjusted by the operator depending on the intended use.
[0000]
TABLE 1
Temperature-corrected capacitance values for complete fills
All bloods
All CS
Parameter
results
results
Mean capacitance (nF)
515
664
SD (nF)
16
27
Mean − 4 * SD (nF)
451
556
[0125] The chart of FIG. 19 shows a correlation of capacitance and bias to a reference glucose measurement (YSI, Yellow Springs Instrument). The measured glucose concentrations were converted to a bias by comparing it to a glucose measurement performed with a reference instrument. Several test strips were filled with various volumes of blood, and the capacitance and glucose concentrations were measured with the test voltage waveform of FIG. 6 . More particularly, the capacitance was measured during the third test voltage V 3 where the test current is relatively large and decreases rapidly with time. Additionally, the capacitance measurements were performed where the limiting test current occurs on the first electrode, which has a reagent layer coating.
[0126] If it is assumed that the main contributor to the bias to YSI is caused by the percentage partial coverage of the electrodes with liquid, then the capacitance values should form a straight line with relatively little scatter when correlated to the YSI bias. For example, a 50% negative bias to YSI should correspond to a 50% decrease in capacitance compared to a fully-filled test strip. Thus, if it is also assumed that the strip-to-strip variation in bias is relatively small, then the relatively large scatter of data points in FIG. 19 can be ascribed to a relatively large variation in the capacitance measurements. It was found that capacitance variation was caused by performing the capacitance measurement during the third test voltage where the test current values are generally not relatively constant.
[0127] A relatively large scatter in the capacitance measurements could cause a significant number of fully-filled test strips to be rejected. Further, a large capacitance variation can cause some capacitance measurements to be biased low, and thus, be below a sufficiently filled threshold resulting in a falsely identified partial fill.
[0128] The chart of FIG. 20 shows a correlation of capacitance (measured at about 1.3 seconds) and bias to a reference glucose measurement (YSI, Yellow Springs Instrument). Several test strips were filled with various volumes of blood, and the capacitance and glucose concentrations were measured with the test voltage waveform of FIG. 6 . More particularly, the capacitance was measured during the second test voltage V 2 where the test current is relatively constant. In addition, the capacitance measurement was performed where the limiting test current occurs on the second electrode, which did not have a reagent layer coating. In contrast to FIG. 19 , the data in FIG. 20 shows that the capacitance values are less scattered.
[0129] The chart of FIG. 21 shows a correlation of capacitance (measured at about 1.3 seconds) and bias to a reference glucose measurement (YSI, Yellow Springs Instrument). Several test strips were filled with various volumes of CS, and the capacitance and glucose concentrations were measured with the test voltage waveform of FIG. 6 . Similar to FIG. 20 , the data in FIG. 21 shows that the capacitance values have a relatively low amount of variation when performed during this time interval.
Double-Dosing Events
[0130] A double dose occurs when a user applies an insufficient volume of blood to a sample-receiving chamber and then applies a subsequent bolus of blood to further fill the sample-receiving chamber. An insufficient volume of blood expressed on a user's fingertip or a shaky finger can cause the occurrence of a double-dosing event. The currently disclosed system and method can be configured to identify such double-fill events. For example, FIG. 22 shows a test current transient where a user performed a double-dosing event during the second test time interval t 2 that caused a spike to be observed (see solid line). When there is no double-dosing event, the test current transient does not have a peak (see dotted line of FIG. 22 ).
[0131] A double-dosing event can cause a glucose test to have an inaccurate reading. Thus, it is usually desirable to identify a double-dosing event and then have the meter output an error message instead of outputting a potentially inaccurate reading. A double-dosing event initially causes the measured test current to be low in magnitude because the electrode area is effectively decreased when only a portion is wetted with sample. Once the user applies the second dose, a current spike will occur because of a sudden increase in the effective electrode area and also because turbulence causes more reduced mediator to be transported close to the working electrode. In addition, less ferrocyanide will be generated because a portion of the reagent layer is not wetted by sample for the entire test time. Thus, an inaccurate glucose reading can result if a test current value used in the glucose algorithm is depressed or elevated as a result of the double-dosing.
[0132] A method of identifying a double-dosing event ( 1006 a , 1006 b , or 1006 c ) may include measuring a second test current and a third test current where the second test current occurs before the third test current. An equation may be used to identify double-dosing events based on a difference between the absolute value of the third test current and the absolute value of the second test current. If the difference is greater than a predetermined threshold, the test meter may output an error message indicative of a double-dosing event. The method of identifying the double-dosing event may be performed multiple times in serial manner as the test current values are collected by the test meter. The equation can be in the form of Equation 31 for calculating a difference value Z 2 for determining whether a double-dosing event had occurred:
[0000] Z 2 =abs( i ( t+x ))−abs( i ( t )) Eq. 31
[0000] where i(t) is a second test current, i(t+x) is a third test current, t is a time for the second test current, and x is an increment of time in between current measurements. If the value Z 2 is greater than a predetermined threshold of about three (3) microamperes, then the test meter may output an error message due to a double-dosing event. The predetermined thresholds disclosed herein are illustrative for use with test strip 100 and with the test voltage waveform of FIG. 6 where working electrode and reference electrode both have an area of about 0.042 cm 2 and a distance between the two electrodes ranging from about 90 microns to about 100 microns. It should be obvious to one skilled in the art that such predetermined thresholds may change based on the test strip design, the test voltage waveform, and other factors.
[0133] In another embodiment for identifying a double-dosing event (e.g., 1006 a , 1006 b , or 1006 c ), a method may include measuring a first test current, a second test current, and third test current where the first test current occurs before the second test current and the third test current occurs after the second test current. An equation may be used to identify double-dosing events based on two times the absolute value of the second test current minus the absolute value of first test current and minus the absolute value of the third test current. The equation may be in the form of Equation 32 for calculating a summation value Y for determining whether a double-dosing event had occurred:
[0000] Y= 2* abs( i ( t ))−abs( i ( t−x ))−abs( i ( t+x )) Eq. 32
[0000] where i(t) is a second test current, i(t−x) is a first test current, i(t+x) is a third test current, t is a time for the second test current, and x is an increment of time in between measurements, and abs represents an absolute function. If the summation value Y is greater than a predetermined threshold, then the test meter may output an error message due to a double-dosing event. The predetermined threshold may be set to a different value for the first time interval t 1 , second time interval t 2 , and third time interval t 3 .
[0134] In one embodiment the predetermined threshold may be about two (2) microamperes for the first time interval t 1 , about two (2) microamperes for the second time interval t 2 , and about three (3) microamperes for the third time interval t 3 . The predetermined thresholds may be adjusted as a result of the following factors such as noise in the test meter, frequency of test current measurements, the area of the electrodes, the distance between the electrodes, the probability of a false positive identification of a double-dosing event, and the probability of a false negative identification of a double-dosing event. The method of identifying the double-dosing event using Equation 32 can be performed for multiple portions of the test current transient. It should be noted that Equation 32 can be more accurate than Equation 31 for identifying double-dosing events because the first test current and third test current provide a baseline correction. When using the test voltage waveform of FIG. 6 , the double-dosing check can be performed at a time period just after the beginning of the first, second, and third time intervals because a peak typically occurs at the beginning of the time intervals. For example, the test currents measured at zero seconds to about 0.3, 1.05, and 4.05 seconds should be excluded from the double-dosing check.
Maximum Current Check
[0135] As referred to in steps 1012 a , 1012 b , and 1012 c of FIG. 18 , a maximum current check can be used to identify a test meter error or a test strip defect. An example of a test meter error occurs when the blood is detected late after it is dosed. An example of a defective test strip occurs when the first and second electrode are shorted together. FIG. 23 shows a test current transient where the test meter did not immediately detect the dosing of blood into the test strip (see solid line). In such a scenario, a late start will generate a significant amount of ferrocyanide before the second test voltage V 2 is applied causing a relatively large test current value to be observed. In contrast, when the test meter properly initiates the test voltage waveform once blood is applied, the test current values for the second time interval are much smaller, as illustrated by the dotted line in FIG. 23 .
[0136] A late start event can cause an inaccurate glucose reading. Thus, it would be desirable to identify a late start event and then have the meter output an error message instead of outputting an inaccurate reading. A late start event causes the measured test current to be larger in magnitude because there is more time for the reagent layer to generate ferrocyanide. Thus, the increased test current values will likely distort the accuracy of the glucose concentration.
[0137] In addition to a test meter error, a short between the first and second electrode can cause the test current to increase. The magnitude of this increase depends on the magnitude of the shunting resistance between the first and second electrode. If the shunting resistance is relatively low, a relatively large positive bias will be added to the test current causing a potentially inaccurate glucose response.
[0138] Maximum current check ( 1012 a , 1012 b , and 1012 c ) can be performed by comparing the absolute value of all of the measured test current values to a predetermined threshold and outputting an error message if the absolute value of one of the measured test current values is greater than the predetermined threshold. The predetermined threshold can be set to a different value for the first, second, and third test time intervals (t 1 , t 2 , and t 3 ). In one embodiment, the predetermined threshold may be about 50 microamperes for the first time interval t 1 , about 300 microamperes for the second time interval t 2 , and about 3000 microamperes for the third time interval t 3 .
Minimum Current Check:
[0139] As referred to in steps 1014 b and 1014 c of FIG. 18 , a minimum current check can be used to identify a false start of a glucose test, an improper time shift by a test meter, and a premature test strip removal. A false start can occur when the test meter initiates a glucose test even though no sample has been applied to the test strip. Examples of situations that can cause a test meter to inadvertently initiate a test are an electrostatic discharge event (ESD) or a temporary short between first and second electrodes. Such events can cause a relatively large current to be observed for a least a short moment in time that initiates a test even though no liquid sample has been introduced into the test strip.
[0140] An inadvertent initiation of a glucose test can cause a test meter to output a low glucose concentration even though no sample has yet been applied to the test strip. Thus, it would be desirable to identify an inadvertent initiation of a glucose test so that the test meter does not output a falsely low glucose reading. Instead, the test meter should provide an error message that instructs the user to re-insert the same test strip or to insert a new test strip for performing the test again.
[0141] A time shifting error by the test meter can occur when the third test voltage V 3 is applied early or late. An early application of the third test voltage V 3 should cause the test current value at the end of the second time interval t 2 to be a relatively large current value with a positive polarity instead of a relatively small current value with a negative polarity. A late application of the third test voltage V 3 should cause the test current value at the beginning of the third time interval to be a relatively small current value with a negative polarity instead of a relatively large current value with a positive polarity. For both the early and late application of the third test voltage V 3 , there is a possibility of causing an inaccurate glucose result. Therefore, it would be desirable to identify a time shifting error by the test meter using the minimum current check so that an inaccurate glucose reading does not occur.
[0142] A premature removal of a test strip from the test meter before the end of a glucose test can also cause an inaccurate glucose reading to occur. A test strip removal would cause the test current to change to a value close to zero potentially causing an inaccurate glucose output. Accordingly, it would also be desirable to identify a premature strip removal using a minimum current check so that an error message can be provided instead of displaying an inaccurate glucose reading.
[0143] The minimum current check may be performed by comparing the absolute value of all of the measured test current values during the second and third time intervals (t 2 and t 3 ) to a predetermined threshold and outputting an error message if the absolute value of one of the measured test current values is less than a predetermined threshold. The predetermined threshold may be set to a different value for the second and third test time intervals. However, in one embodiment, the predetermined threshold may be about 1 microampere for the first time interval t 1 and the second time interval t 2 . Note that the minimum current check was not performed for the first time interval because the test current values are relatively small because the first test voltage V 1 is close in magnitude to the redox potential of the mediator.
High Resistance Track:
[0144] As referred to in step 1022 c of FIG. 18 , a high resistance track can be detected on a test strip that can result in an inaccurate glucose reading. A high resistance track can occur on a test strip that has an insulating scratch or a fouled electrode surface. For the situation in which the electrode layers are made from a sputtered gold film or sputtered palladium film, scratches can easily occur during the handling and manufacture of the test strip. For example, a scratch that runs from one lateral edge 56 to another lateral edge 58 on first electrode layer 66 can cause an increased resistance between first contact pads 67 and first electrode 166 . Sputtered metal films tend to be very thin (e.g., 10 to 50 nm) making them prone to scratches during the handling and manufacture of the test strip. In addition, sputtered metal films can be fouled by exposure to volatile compounds such as hydrocarbons. This exposure causes an insulating film to form on the surface of the electrode, which increases the resistance. Another scenario that can cause a high resistance track is when the sputtered metal film is too thin (e.g., <<10 nm). Yet another scenario that can cause a high resistance track is when the test meter connectors do not form a sufficiently conductive contact to the test strip contact pads. For example, the presence of dried blood on the test meter connectors can prevent a sufficiently conductive contact to the test strip contact pads.
[0145] FIG. 24 shows two test current transients during a third time interval t 3 for a test strip having a high resistance track (squares) and a low resistance track (triangles). A sufficiently high track resistance R that is between the electrode and the electrode contact pad can substantially attenuate the magnitude of the effectively applied test voltage V eff , which in turn can attenuate the magnitude of the resulting test current. The effective test voltage V eff can be described by Equation 33:
[0000] V eff =V−i ( t ) R. Eq. 33
[0000] Generally, V eff will be the most attenuated at the beginning of the third time interval t 3 where the test current will generally have the highest magnitude. The combination of a relatively large R and a relatively large test current at the beginning of the third time interval t 3 can cause a significant attenuation in the applied test voltage. In turn, this could cause an attenuation of the resulting test current at the beginning of the third time interval t 3 , as illustrated in FIG. 24 at t=4.05 seconds. Such attenuation in the peak current immediately at about 4.05 seconds can cause the calculated glucose concentration to be inaccurate. In order to avoid significant attenuation in the applied test voltage, R should be a relatively small value (i.e., low track resistance). In one embodiment, a low resistance track may be represented by an electrode layer having a resistivity of less than about 12 ohms per square and a high resistance track may be represented by an electrode layer having a resistivity of greater than about 40 ohms per square.
[0146] A determination of whether a test strip has a high track resistance can use an equation based on a first test current i 1 and a second test current i 2 that both occur during the third time interval t 3 . The first test current i 1 may be measured at about a beginning of the third time interval t 3 (e.g., 4.05 seconds) where the magnitude is at a maximum or close to the maximum. The second test current i 2 may be measured at about an end of the third time interval t 3 (e.g., 5 seconds) where the magnitude is at the minimum or close to the minimum.
[0147] The equation for identifying a high track resistance may be in the form of Equation 34:
[0000]
R
1
=
i
1
i
1
-
i
2
.
Eq
.
34
[0000] If first ratio R 1 is greater than a predetermined threshold, then the test meter may output an error message due to the test strip having a high resistance track. The predetermined threshold may be about 1.2. It is significant that the first test current i 1 is about a maximum current value because it is the most sensitive to resistance variations according to Equation 33. If a first test current i 1 is measured at a time that was closer to the minimum current value, then Equation 34 would be less sensitive for determining whether a high resistance track was present. It is advantageous to have relatively low variation in the first ratio R 1 when testing low resistance test strips. The relatively low variation decreases the likelihood of mistakenly identifying a high resistance track test strip. As determined and described herein, the variation of first ratio R 1 values for test strips having a low resistance track is about four times lower when a first test current value i 1 was defined as a current value immediately after the application of the third test voltage V 3 , as opposed to being a sum of current values during the third time interval t 3 . When there is a high variation in first ratio R 1 values for low resistance test strips, the probability of mistakenly identifying a high resistance track increases.
[0148] FIG. 25 is a chart showing a plurality of R 1 values calculated with Equation 34 for two test strip lots where one lot has a high resistance track and the other lot has a low resistance track. One lot of test strip was purposely manufactured with a high resistance track by using palladium electrodes that were purposely fouled by an exposure to gas containing hydrocarbons for several weeks. The second test strip lot was manufactured without purposely fouling the electrode surface. To prevent fouling, a roll of sputtered coated palladium was coated with MESA before coating with the reagent layer. All of the low resistance test strips, which were not fouled, had R 1 values of less than 1.1 indicating that Equation 34 could identify low track resistance test strips. Similarly, essentially all of the high resistance test strips, which were purposely fouled, had R 1 values of greater than 1.1 indicating that Equation 34 could identify high track resistance test strips.
Leakage
[0149] As previously referred to in step 1024 c in FIG. 18 , a leakage can be detected on a test strip when the spacer 60 does not form a sufficiently strong liquid impermeable seal with the first electrode layer 66 . A leakage occurs when liquid seeps in between the spacer 60 and the first electrode 166 and/or the second electrode 164 . Note that FIG. 4B shows a reagent layer 72 that is immediately adjacent to the walls of the spacer 60 . However, in another embodiment (not shown) where leakage is more likely to occur, the reagent layer 72 can be have an area larger than the cutout area 68 that causes a portion of the reagent layer 72 to be in between the spacer 60 and the first electrode layer 66 . Under certain circumstances, interposing a portion of the reagent layer 72 in between the spacer 60 and the first electrode layer 66 can prevent the formation of a liquid impermeable seal. As a result, a leakage can occur which creates an effectively larger area on either the first electrode 166 , which in turn, can cause an inaccurate glucose reading. An asymmetry in area between the first electrode 166 and the second electrode 164 can distort the test current transient where an extra hump appears during the third time interval t 3 , as illustrated in FIG. 26 .
[0150] FIG. 16 shows test current transients during a third time interval t 3 for three different types of test strip lots where test strip lot 1 (squares) has a leakage of liquid between the spacer and the first electrode. Test strip lot 1 was constructed using a dryer setting that did not sufficiently dry the reagent layer and also was laminated with a pressure setting that was not sufficient to form a liquid impermeable seal to the electrodes. Normally, the reagent layer is sufficiently dried so that an adhesive portion of the spacer 60 can intermingle with the reagent layer and still form a liquid impermeable seal to the first electrode layer 166 . In addition, sufficient pressure must be applied so that the adhesive portion of the spacer 60 can form the liquid impermeable seal to the first electrode layer 166 . The test strip lot 2 was prepared similarly to test strip lot 1 except that they were stored at about 37 degrees Celsius for about two weeks. The storage of the test strip lot 2 caused the spacer to reform creating a liquid impermeable seal to the electrodes. Test strip lot 3 was constructed using a dryer setting that was sufficient to dry the reagent layer and also was laminated with a pressure setting sufficient to form a liquid impermeable seal. Both test strip lots 2 and 3 (triangles and circles respectively) show a more rapid decay in the test current magnitude with time compared to test strip 1 (squares), as illustrated in FIG. 26 .
[0151] A determination of whether a test strip leaks can be performed using an equation based on a first test current, a second test current, a third test current, and a fourth test current that occur during the third test time interval. A first logarithm of a second ratio can be calculated based on a first test current i 1 and a second test current i 2 . A second logarithm of a third ratio can be calculated based on a third test current i 3 and a fourth test current 14 . An equation may be used to calculate a fourth ratio R 4 based on the first logarithm and the second logarithm. If the fourth ratio R 4 is less than a predetermined ratio, then the test meter will output an error message due to leakage. The predetermined threshold may range from about 0.95 to about 1. The equation for identifying leakage can be in the form of Equation 35:
[0000]
R
4
=
log
(
i
1
i
2
)
log
(
i
3
i
4
)
.
Eq
.
35
[0000] In one embodiment, the first test current i 1 and the second test i 2 current may be about the two largest current values occurring the third time interval t 3 , the fourth test current i 4 may be a smallest current value occurring the third time interval t 3 , and the third test current i 3 may be selected at a third test time so that a difference between the fourth test time and a third test time is greater than a difference between a second test time and a first test time. In one illustrative embodiment, the first test current, the second test current, the third test current, and the fourth test current may be measured at about 4.1 seconds, 4.2 seconds, 4.5 seconds, and 5 seconds, respectively.
[0152] FIG. 27 is a chart showing a plurality of R 4 values calculated with Equation 35 for the three test strip lots described for FIG. 26 . Accordingly, test strip lot 1 has fourth ratio values less than one and both test strip lots 2 and 3 have fourth ratio R 4 values greater than one indicating that Equation 35 can successfully identify strip leakages.
[0153] In an alternative embodiment, a determination of whether a test strip has a leakage can be performed using an equation based on only three test current values instead of using four test current values as shown in Equation 35. The three test current values may include a first test current i 1 , a third test current i 3 , and a fourth test current i 4 that all occur during the third test time interval t 3 . A third logarithm of a fifth ratio may be calculated based on the first test current i 1 and the third test current i 3 . A second logarithm of a third ratio may be calculated based on the third test current i 3 and the fourth test current i 4 . An equation may be used to calculate a sixth ratio R 6 based on the third logarithm and the second logarithm. If R 6 is less than a predetermined ratio, then the test meter will output an error message due to leakage. The equation for identifying leakage may be in the form of Equation 36:
[0000]
R
5
=
log
(
i
1
i
3
)
log
(
i
3
i
4
)
.
Eq
.
36
[0154] One skilled in the art will appreciate further features and advantages of the present disclosure based on the above-described embodiments. Accordingly, the present disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.
|
Methods for calculating an analyte concentration of a sample are provided. In one exemplary embodiment the method includes steps that are directed toward accounting for inaccuracies that occur as a result of temperature variations in a sample, a meter, or the surrounding environment. In another exemplary embodiment the method includes steps that are directed toward determining whether an adequate sample is provided in a meter because insufficient samples can result in inaccuracies. The methods that are provided can be incorporated into a variety of mechanisms, but they are primarily directed toward glucose meters for blood samples and toward meters for controls solutions.
| 6
|
REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of Ser. No. 08/743,784 filed Nov. 7, 1996, which is hereby incorporated by reference.
TECHNICAL FIELD
This invention relates generally to an apparatus for establishing communication paths over a circuit switched network, a connectionless packet switched network, and a connection-oriented packet switched network, and more particularly to an apparatus for establishing point-to-point or point-to-multipoint audio or video communication over a telephony network, the Internet, and an Asynchronous Transfer Mode (ATM) or a Frame Relay (FR) network.
BACKGROUND OF THE INVENTION
Voice traffic transmitted between two or more users over a telephony network is carried over circuit-switched paths that are established between the users. Circuit-switched technology is well-suited for delay-sensitive, real-time applications such as voice transmission since a dedicated path is established. In a circuit-switched network, all of the bandwidth of the established path is allocated to the voice traffic for the duration of the call.
In contrast to the telephony network, the Internet is an example of a connectionless packet-switched network that is based on the Internet Protocol (IP). While the majority of the traffic carried over the telephony network is voice traffic, the Internet is more suitable to delay-insensitive applications such as the transmission of data. The Internet community has been exploring improvements in IP so that voice can be carried over IP packets without significant performance degradation. For example, the resource reservation protocol known as RSVP (see RSVP Version 2 Functional Specifications, R. Braden, L. Zhang, D. Estrin, Internet Draft 06, 1996) provides a technique for reserving resources (i.e. bandwidth) for the transmission of unicast and multicast data with good scaling and robustness properties. The reserved bandwidth is used to effectively simulate the dedicated bandwidth scheme of circuit-switched networks to transmit delay-sensitive traffic. If RSVP is implemented only for those communications having special Quality of Service (QoS) needs such as minimal delay, the transmission of other communications such as non-real time data packets may be provided to other users of the Internet in the usual best-effort, packet-switched manner.
The majority of Internet users currently access the Internet via slow-speed dial/modem lines using protocols such as SLIP (serial line IP) and PPP (Point to Point Protocol), which run over serial telephone lines (modem and N-ISDN) and carry IP packets. Voice signals are packetized by an audio codec on the user's multimedia PC. The voice packets carry substantial packetization overhead including the headers of PPP, IP, UDP, and RTP, which can be as big as 40 octets. Transmitting voice packets over low speed access lines is almost impossible because of the size of the header relative to the size of a typical voice packet (20-160 octets, based on the average acceptable voice delay and amount of voice compression). However, several proposals have emerged to compress the voice packet headers so that greater transmission efficiency and latency can be achieved for voice-packets transmitted over low-speed, dial access lines.
A substantial number of users is expected to begin sending voice traffic over the Internet with acceptable voice quality and latency because of the availability of RSVP and packet-header compression technologies. The transmission terminals for sending packetized voice over the Internet are likely to be multimedia personal computers.
In addition to the telephony network and the Internet, other transmission standards such as Frame-Relay and ATM have been emerging as alternative transport technologies for integrated voice and data. ATM/FR networks are similar to the telephony network in that they both employ connection-oriented technology. However, unlike the telephony network, ATM/FR networks employ packet switching. In contrast to the Internet Protocol, which is a network layer protocol (layer three), FR and ATM pertain to the data link layer (layer two) of the seven-layer OSI model.
Frame Relay and ATM can transport voice in two different formats within the FR (or ATM) packets (cells). In the first format, the FR (ATM) packets (cells) carry an IP packet (or some other layer-3 packet), which in turn encapsulates the voice packets. Alternatively, the FR (ATM) packets (cells) directly encapsulate the voice packet, i.e., without using IP encapsulation. The first alternative employs protocols such as LAN Emulation (LANE), Classical IP Over ATM, and Multiprotocol Over ATM (MPOA), all of which are well known in the prior art. The second alternative is referred to as “Voice over FR” and “Voice over ATM”, respectively. Note that the first alternative, which includes IP encapsulation, allows voice packets to be routed between IP routers. That is, layer-3 processing is performed by the routers along the voice path to determine the next hop router. The second alternative is a purely FR/ATM switched solution. In other words, switching can be performed only at the data link layer. FIG. 1 depicts the protocol stacks for transport of voice over IP and the two alternatives for voice over FR/ATM.
The audio codec depicted in FIG. 1 enables voice encoding/decoding, including voice digitization, compression, silence elimination and formatting. The audio codec is defined by ITU-T standards such as G.711 (PCM of Voice Frequencies), G.722 (7 Khz Audio-Coding within 64 Kbps), G.723 (Dual Rate Speech Code for Multimedia Telecommunications Transmitting at 6.4 and 5.3 Kbps), and G.728 (Speech Encoding at 16 Kbps).
The “Voice over ATM/FR layer” depicted in FIG. 1 is referred to as the multimedia multiplex and synchronization layer, an example of which is defined in ITU-T standard H.222. ITU-T is currently defining the H.323 standard, which specifies point-to-point and multipoint audio-visual communications between terminals (such as PCs) attached to LANs. This standard defines the components of an H.323 system including H.323 terminals, gate-keepers, and multi-point control units (MCUs). PCs that communicate through the Internet can use the H.323 standards for communication with each other on the same LAN or across routed data networks. In addition to H.323, the ITU-T is in the process of defining similar audio-visual component standards for B-ISDN (ATM) in the H.310 standard, and for N-ISDN in the H.320 standard. The previously mentioned standards also define call signaling formats. For example, IP networks use Q.931 call controls over a new ITU-T standard known as H.225 (for H.323 terminals). Telephony networks use Q.931 signaling and ATM networks use Q.2931 signaling.
Many standards bodies are in the process of defining how voice (and video) can be transported within a given homogenous network such as the telephony, IP, FR and ATM networks. However, there is currently no arrangement for transmitting voice over a heterogeneous network that consists of two or more such networks employing different transmission standards.
Summary of the Invention
In accordance with the principles of the invention, the foregoing problem is addressed by employing a gateway which connects to the telephony network, the Internet and the ATM/FR network. Such gating facilities are needed if communication getween users on different networks are to be allowed. The telephony network, Internet and FR/ATM Networks all use different schemes for establishing a voice session (i.e., call set-up protocols), and different formats for controlling a session and transporting voice. The gateway of the present invention provides conversion of the transmission format, control, call signaling and audio stream (and potentially video and data streams) between different transmission standards.
Embodiments of the disclosed gateway provide some or all of the following functions: call-signaling protocol conversion, audio mixing/bridging or generation of composite audio and switching, address registration, address translation, audio format conversion, audio coding translation, session management/control, address translation between different address types, interfacing with other gateways, interfacing with the SS7 signaling network, and interfacing with an Internet signaling network.
The apparatus establishes a communication session between first and second terminals that may be resident in networks that employ differing transmission standards. The different networks may, illustratively, be a circuit switched network (e.g., a telephony network), a connectionless packet switched network (e.g., the Internet) or a connection-oriented packet switched network (e.g., an ATM or frame relay network). The communication session may be an audio session, a video session or a multimedia session.
The apparatus includes a call set-up translator for translating among call set-up protocols associated with the circuit switched network, the connectionless packet switched network and the connection-oriented packet switched network. An encoding format translator is provided for translating among encoding protocols associated with the circuit switched network, the connectionless packet switched network and the connection-oriented packet switched network. Also provided is an address database for storing a plurality of addresses in different formats for each registered terminal, which includes the first and second terminals. The apparatus also includes a session manager for storing control information relating to the first and second terminals. The control information includes an identification of the first and second terminals that participate in the communication session. Participation in a conversation by more than a pair of terminals is easily accommodated by the disclosed gateway.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a simplified protocol stack for transporting voice over an IP network, a telephony network (e.g., an ISDN network) and an ATM/FR network;
FIG. 2 shows a gateway in accordance with the present invention situated among a telephony network, an IP network and a AM/FR network;
FIG. 3 shows a plurality of gateways interfacing with one another and with user terminals;
FIG. 4 shows a simplified diagram of a gateway interconnected with various networks;
FIG. 5 is a block diagram showing the functionality of various interfaces of which the gateway is comprised;
FIG. 6 shows a flow chart of an exemplary method for processing calls through the gateway in accordance with the present invention; and
FIG. 7 is a block diagram of one embodiment of the gateway shown in FIGS. 2-4.
DETAILED DESCRIPTION
FIG. 2 shows a gateway 100 in accordance with the present invention. As shown, gateway 100 communicates with networks employing differing transmission standards such as telephony network 52 , ATM/FR network 57 and Internet 53 . Illustratively, gateway 100 is connected to a switch, router or server, and an ATM/FR switch, which are within telephony network 52 , Internet network 53 , and ATM/FR network 57 , respectively. Gateway 100 facilitates voice communication between a variety of end-point stations connected to the individual networks. Such stations may include telephone 61 , fax machine/telephone 62 , and PC 63 (which are connected to the telephony network 52 ), PCs 71 and 72 (which are connected to the Internet 53 ) and workstations 81 and 82 (which are connected to the ATM/FR network 57 ).
An illustrative functional embodiment of gateway 100 in conformance with FIG. 2 is presented in FIG. 4 . Networks 52 , 53 , and 57 , are three different networks that are connected to gateway 100 . Network 52 is the conventional, well known, telephone network, network 53 is an internet network, and network 57 is an ATM/Frame Relay network. This, of course, is merely illustrative, and it should be appreciated that any number of networks can be coupled to gateway 100 , that not all of the networks must be different from each other, and that the illustrated set of types of networks is not exhaustive.
Each network that connects to gateway 100 has an interface block. Thus, gateway 100 in FIG. 4 has an interface bus 301 for connecting Internet network 53 to interface block 311 , an interface bus 302 for connecting telephony network 52 to interface block 312 , and an interface bus 303 for connecting ATM/FR network 57 to interface block 313 . Within network interface 311 there is an IP call setup module 101 and an IP mixer 201 . Within network interface 312 there is a telephony call signaling module 102 and a telephony bridge 202 . Within network interface 313 there is an ATM/FR call signaling module 103 and an ATM mixer 203 . Each one of the interfaces ( 311 , 312 , and 313 ) is connected to a signaling format adaptation module 104 , to a voice format adaptation module 204 , and to session manager 304 . Thus, module 104 handles the signaling handled among the network interfaces ( 311 , 312 , and 313 ); module 204 handles communication (e.g. conversation) signals flowing among the network interfaces; and session manager handles session managing needs of conversations passing through gateway 100 . In the context of this disclosure, a session corresponds to the activities that set-up a call, that carry on communication, and that tear-down a call.
A number of different approaches can be taken for handling the signal formats between interfaces 311 , 312 , and 313 on the one hand, and processing elements 104 , 204 , and 304 , on the other. One approach is to allow interfaces 311 , 312 , and 313 to operate in formats that are native to the networks with which they interface. For example, signals between the core elements (elements 104 , 204 , and 304 ) and interface 311 may be in a format acceptable to IP network 53 , signals between the core elements and interface 312 may be in a format acceptable to telephony network 52 , and signals between the core elements and interface 313 may be in a format acceptable to ATM/FR network 57 . Another approach is to employ a chosen, generic, format and have all interfaces (elements 311 , 312 , and 313 ) interact with the core elements in that generic format. Of course, all functions and other conversions that need to be performed by the gateway are carried out by the core elements or the interface elements. The division of labor between the core elements and the interfaces is a matter of designer choice.
Interface 311 includes an IP call setup unit 101 and an IP mixer 201 , interface 312 includes telephony signaling unit 102 and telephone bridge 202 , and interface 313 includes ATM/RF call signaling unit 103 and ATM Mixer 203 . Units 101 , 102 , and 103 are involved in establishing calls, and units 201 , 202 , and 203 are involved in combining voice signals.
When an IP station in network 53 wishes to establish a call, for example with a conventional POTS telephone in network 52 , it sends an appropriate signaling packet to its Internet Service Provider (ISP). That signaling packet eventually arrives at unit 101 , and unit 101 determines that the packet wishes to establish service with a particular POTS telephone. Element 104 determines the POTS phone number of the called party, and forwards a call set up request to unit 102 . The POTS number is determined either from the signaling packet, or packets, of the IP station, or with the aid of database 105 which is coupled to element 104 . For example, the IP station may specify the called party in terms of an IP address. Database 105 would then translate the IP address to the format desired by network 52 . Most simply, unit 102 is coupled to a central office and simply dials out the called party's number using DTMF signals. In such a case, the called phone number has the familiar 1, area code, exchange, number format. Alternatively, unit 102 can be constructed to possess some of the capabilities that are found in a central office, such as the ability to consult with the SS7 signaling network and to proceed with the call establishment if a line is available. In such an embodiment, unit 102 interfaces with network 52 in the format that is acceptable to network 52 , for example Q.931, and it includes circuitry to interact with the SS7 network. Such circuitry generates SS7 signaling messages to a Network Control Point (NCP) to obtain, for example, a telephone number translation prior to generating an outgoing Q.931 signaling message to the telephony network 52
In the course of sending information from unit 101 to unit 104 , and then to unit 102 , some signal conversion must necessarily occur. As indicated above, this can occur by unit 101 converting the information in the signaling pocket(s) to information formatted in a selected generic format. In such a case, unit 104 accepts the information in the generic format, performs its analysis, forwards the necessary information to unit 102 in the same generic format, and unit 102 converts the information to a format that is suitable for telephony network 52 . Alternatively, unit 101 sends information in IP format to unit 104 , unit 104 ascertains what that information is, formats the necessary information into a format acceptable to unit 102 (e.g. DTMF, or Q.931), and forwards the formatted information to unit 102 . Element 101 also monitors the status of each call establishment session and transmits error messages as appropriate (in the form of audio messages or digital data) to the IP station, as necessary.
A similar interaction occurs when an IP station wishes to establish a connection with a station in network 57 , except that unit 103 is involved rather than unit 102 (and the format might be Q.2931). Also, a similar interaction occurs when a station in some other network wishes to establish communication with a station in IP network 53 . For example, if a POTS telephone wishes to call a station in network 53 , it dials out the called number. The SS7 network identifies the called number as one that must be accessed through gateway 100 and if a path is available, the calling party is connected to interface 312 and the called party number is provided to unit 102 . Unit 102 sends the necessary information to signaling format adaptation unit 104 which, with the aid of database 105 , converts the dialed phone number into an IP address of the called party (IP station). The necessary information is then forwarded to unit 101 , which sends a call establishment packet, or packets, to the called IP station.
For sake of simplicity, the following descriptions relate to an embodiment where signals between interface 311 and the core elements are in IP format, signals between interface 312 and the core elements are in telephony format, and signals between interface 313 and the core elements are in ATM/FR format.
As can be surmised from the above, signaling format adaptation block 104 is a signaling format translator. It translates the call-setup requests from the form with which such requests arrive into a form that the destination interface can properly understand. For example, it generates the information that Q.931 signals need if network 52 is the destination, the information that IP packets need if network 53 is the destination, and/or the information that Q.2931 signals need if network 57 is the destination. It also effects number translations with the aid of database 105 .
Mixer 201 is needed for the occasions when more than one IP terminal participates in the communication. When one IP terminal communicates with, for example, a POTS telephone, the IP terminal encodes the speech in accordance with a particular algorithm and transmits the resulting digital data in IP packet format. The stream of IP packets of that terminal is applied to voice format adaptation block 204 , wherein the encoded speech contained in the packet is decoded and converted to the format needed for the POTS telephone. Conversely, information destined to that IP terminal comes from block 204 already formatted in IP format and in the speech encoding that is suitable for the IP terminal. However, when two or more IP terminals are involved, the situation is more complicated. This is particularly so when the IP terminals that participate in the connection employ different speech encoding algorithms. On the side going to other networks, it is the function of mixer 201 to process incoming packet streams and to create a single packet stream that represents the combined speech signal of the IP terminals that participate in the communication. That IP packet stream is applied to element 204 , and element 204 converts it to the speech signal format of either interface 312 or interface 313 , as appropriate. In the other direction, signals that reach mixer 201 from element 204 and are destined to more than one IP terminal have to be converted to a number of individual IP streams, addressed to the appropriate individual IP terminals. Mixer 201 performs this “demultiplexing” and also insures that each of the IP terminals receives a signal that is encoded in the proper speech encoding algorithm, for example, 16 Kpbs speech encoding (standard G.728) for one IP terminal, and 64 Kbps speech encoding (standard G.722) for another IP terminal. The speech encoding translations are performed in mixer 201 pursuant to information provided to IP mixer 201 by session manager 304 .
In some embodiments of the invention, the IP packet mixer 201 also provides control functionality that would otherwise be performed by IP call set-up interface 101 . In particular, IP packet mixer 201 performs such control functions when in-band signaling is employed. If out-of-band signaling is employed, the control functions may conveniently reside in IP call set-up interface 101 . In the former situation the IP packet mixer receives control packets over an IP connection such as a dedicated UDP or TCP socket interface, for example. The control packets identify the control information pertaining to the station from which it receives the packet, such as the type of voice encoding that is employed by the station, bandwidth utilization, and Quality-of-Service (QoS) requirements. A QoS requirement relates to a measure of goodness of a service connection. In packet-routing networks, it may relate to the probability of lost packets. Of course, if no control information is provided, previously defined default control parameters may be used. IP packet mixer 201 is also used by an IP station to terminate its participation in a session. The session control information received by the IP packet mixer 201 is forwarded to the session manager 304 to maintain a current database of station requirements.
Voice bridge 202 serves a function that parallels the function of mixer 201 , except that it concerns itself with multiple session participants from network 52 . For example, when more than one voice instrument from network 52 participates in a communication, voice bridge 202 combines the two signals to form a single signal that represents the combination. Likewise, ATM mixer 203 concerns itself with multiple participants from network 57 . As an aside, bridge 202 can be an analog bridge when the incoming signals are analog. It can also be digital, if incoming signals are digital or conversion to digital precedes the bridge.
Voice format adaptation block 204 is a speech format translator. It translates incoming speech that arrives in one particular format and speech encoding standard into a format and speech encoding standard that the destination terminal is adapted to accept. Voice format interface 204 also performs appropriate de-encapsulation (if the incoming signal is from interface 313 ), protocol conversion, echo cancellation, encryption, packetization, etc., before the digitized voice is sent to the IP mixer 201 and/or the ATM/FR mixer 203 for subsequent forwarding.
Address translator 105 is provided to various stations to register using various address formats, such as email address, IP address, E.164 address, MAC address and/or ATM NSAP address formats, etc. This allows element 104 to translate addresses from one address format to another.
Session manager interface 304 is employed to receive control information from the mixers, bridges and call set-up interfaces which pertains to the capabilities and status of those stations participating in the communication session. Session manager interface 304 assists the IP mixer 201 , telephony bridge 202 and FR/ATM mixer 203 in forwarding voice traffic to all participating stations.
In an initial, commercial, introduction of the gateway disclosed herein, it is possible that a telecommunications services provider may find that a single gateway will suffice. However, most telecommunications services providers own networks that span a large geographic area, and the different types of networks that they own have roughly the same geographic footprint. Since most subscribers make most of their calls to subscribers that are geographically close, it is quite possible that even in an initial introduction of the gateway disclosed herein, the telecommunications services provider will find it advantageous to employ more than one gateway. In accordance with the principles of this invention, when more than one gateway is used it may be found advantageous to interconnect these gateways in a wide area network (WAN). In this manner, calls from a terminal in one type of network to a terminal in another type of network would pass through one gateway, or perhaps through more than one gateway, based on the geographic distance between the calling and called parties. More specifically, under normal circumstances it is expected that when the distance is short, only one gateway would be employed. When the distance is large, two or more gateways would be employed. It may be noted in passing that use of the term WAN does not intend to suggest any particular network arrangement, because any network that interconnects geographically disperse gateways will do. This includes hierarchical and not hierarchical networks, fault tolerant and non-fault tolerant networks, etc.
FIG. 3 illustrates one arrangement of a WAN which, in a sense, is a hierarchical network. It includes gateways 150 , 110 , and 120 which are connected to each other and which make up the highest level in the hierarchical structure. A lower level is also shown, and it comprises gateways 130 and 140 . The arrangement illustrated in FIG. 3 does not show a direct connection between gateways 130 and 140 but such a connection may be permitted. As depicted, the FIG. 3 network can be also thought to comprise “master” gateways 100 , 110 , and 120 , and “slave” gateways 130 and 140 .
Each of the gateways, whether a master gateway or a slave gateway, can support subscribers from one or more diverse networks. The gateways for the FIG. 3 arrangement can be replicas of the FIG. 4 gateway, except that those gateways that support subscribers from less that all of the different networks can be constructed with fewer components. Illustratively, if the three networks that are shown in FIG. 2 constitute all of the different network to be served, and one of the gateways supports only customers from one, or perhaps two of the networks then, of course, that gateway may be constructed with fewer than all of the elements shown in FIG. 4 .
Bus 109 in FIG. 4, which carries signals from elements 104 , 204 and 304 , is the bus that is used to couple gateways to each other. The format of the signals that bus 109 carries is a matter for designer's choice. Certainly, it should permit any possibly of connections. Perhaps the most challenging connection occurs when a conference call is conducted with six participant (in the context of the three diverse networks of FIG. 2 ), where two gateways are involved, and each gateway services one subscriber in each of the three diverse networks. Given some thought, it becomes apparent that in such a connection, bus 109 cannot simply employ the signal format of the network from which a subscriber calls (i.e. choose to not make any conversion). Some conversions must be made. This, however, does not dictate that some format be fixedly selected. The format employed on bus 109 may be the format of one of the networks, may be some generic format that is a super-set of the other three formats, may be the format of the first subscriber that initiates the conference call, etc.
As illustrated in FIG. 5 gateway 100 also connects to various common Operations Administration Management and Provisioning (OAM&P) functions, databases/directories (e.g., authentication databases such as for credit card authorization), and signaling network intelligence that reside within the SS7 signaling network such as a network control point (NCP) and an Internet NCP residing within the Internet. For example, an NCP may be used by the telephony call set-up interface 102 to translate an 800 number into a telephone number. Similarly, an Internet NCP may be used by the IP call set-up interface 101 to request a translation of a station's email address, host name, or URL to an IP. The Internet NCPs provide intelligent services, such as discussed in U.S. application Ser. No. 08/618,483.
FIG. 6 shows a flow chart of an exemplary method for establishing a voice session between user stations 300 and 600 of FIG. 3 . Station 300 is an IP station and is provided with direct connectivity to the gateway 150 . Station 600 is an ISDN station, and it communicates with the gateway 120 . The method begins at step 501 when station 300 sends a call signaling request over the Internet to gateway 150 in the form of an IP packet. The IP packet carries signaling information (e.g., in the form of a Q.931 message), including the IP address of the called station 600 . Within gateway 150 , station 600 is connected to interface 301 .
In step 503 ,. IP call set-up interface 101 parses the IP packet, retrieves the IP address of station 600 and communicates that information to element 104 . In step 505 , element 104 sends an address query to the address translator 105 to retrieve another address for station 600 . In step 511 element 105 retrieves an address for station 600 , normally in the format of the network in which station 600 resides. Of course, knowing the network address of station 600 is insufficient to inform the arrangement of which gateway is best to use in order to reach station 600 . Element 105 may have a single designated gateway for station 600 , or it may have a list of gateways arranged in order of priority. Element 105 may also include an associated means (e.g. a processor) for dynamically choosing a gateway for station 600 ; for example, based on traffic conditions in the various telecommunication networks. In other words, the Wide Area Network can employ almost any of the routing techniques that are currently known.
It is also possible that station 600 is known to others by an 800 number. In such a case, it may be advantageous to design the gateway so that element 105 informs element 104 of the fact that the number sought to be translated is an 800 number, and provides to element 104 the 800 number in an appropriate format. This information is sent to element 102 , which interacts with an appropriate database outside the gateway to obtain a proper translation. Of course, one can have a plurality of 800 number-translation databases outside the gateway, and in different formats; in which case, the outputs of database 105 might be different. To account for the above, following step 511 , conditional branch point 513 determines whether address translator 105 returned an 800 number for station 600 .
If the result in step 513 is NO, then the information provided by database 105 reveals the gateway through which it is best to reach station 600 ; which in the illustrative example is gateway 120 . Control then passes to step 601 (FIG. 6 B). Otherwise, control passes to step 515 .
If the result in step 513 is YES, indicating that station 600 was requested by dialing an 800 number, address translator interface 105 sends the 800 number to the IP call set-up interface 101 of gateway 150 in step 515 . In step 517 , IP set-up interface 101 of gateway 150 sends the 800 number to the signaling format interface 104 , which in turn constructs an SS7 message and forwards it to the telephony call set-up interface 102 . In step 519 , the interface 102 sends the SS7 message to the NCP in the signaling network to translate the 800 number into a telephone number. The NCP provides the requested telephone number to the telephony call set-up interface 102 .
Once the proper telephone number is determined, in step 521 interface 102 provides that information to element 104 . Once element 104 obtains the translated number, control returns to step 511 where database 104 is asked to translate the number and to identify the gateway to be employed. Control then passes to step 513 , from which control passes this time to step 601 .
Connection to station 600 is then effected and, once the station 600 is connected across the Telephony Bridge 202 and IP Mixer 201 , a “connection negotiation” is established between the users 300 and 600 in steps 601 and 603 to indicate their respective audio encoding preferences, say G.711 for station 300 and G.723 for station 600 . Note that gateway 150 needs to know the encoding preferences of station 300 while gateway 120 needs to know the encoding preferences of station 600 . Once the station capabilities and preferences are known to each gateway, in step 605 the session managers 304 in both gateways 150 and 120 store a conference table that includes the preferences of both users. Communication proceeds between stations 300 and 600 in step 611 when station 300 sends a voice packet to the IP mixer 201 in gateway 150 , which in turn sends the packet to the IP mixer 201 in gateway 120 .
The method described above in connection with FIG. 6 may be implemented in a similar manner if station 600 is an ISDN terminal that employs voice over ISDN without implementing the Internet protocol.
FIG. 7 is a block diagram of an exemplary embodiment of WAN-based gateway 1001 which includes a) central processing unit (CPU) 1002 , b) interface port 1003 c) data bus 1004 and d) memory 1005 . Central processing unit (CPU) 1002 provides the computational capability necessary to control the processes of gateway 1001 .
Data bus 1004 provides for the exchange of data between the components of gateway 1001 .
Interface port 1003 provides for the exchange of data between gateway 1001 and devices external to Gateway 1001 via link high speed backbone 425 .
To this end, interface port 1003 contains, for example, well-known data transceivers.
Memory 1005 includes 1 ) code portion 1006 , which contains the instructions (program) used by CPU 1002 to control the processes of Gateway 1001 , such as those described herein above, and data storage portion 1007 , which contains the information necessary to the gateway to perform its specific function, such as, address registration and translation.
The foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope.
|
In one embodiment of the invention, an apparatus is provided for establishing a communication session between first and second terminals in communication over a plurality of networks that employ differing transmission standards. The plurality of networks are selected from among a circuit switched network (e.g., a telephony network), a connectionless packet switched network (e.g., the Internet) and a connection-oriented packet switched network (e.g., an ATM or frame relay network). The apparatus includes a call set-up translator for translating among call set-up protocols associated with the circuit switched network, the connectionless packet switched network and the connection-oriented packet switched network. An encoding format translator is provided for translating among encoding protocols associated with the circuit switched network, the connectionless packet switched network and the connection-oriented packet switched network. Also provided is an address database for storing a plurality of addresses in different formats for each registered terminal, which includes the first and second terminals. The apparatus also includes a session manager for storing control information relating to the first and second terminals. The control information includes an identification of the first and second terminals that participate in the communication session.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority from Japanese application JP2013-023528 filed on Feb. 8, 2013, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a touch sensing device and method of identifying the touched position, and more particularly to touch coordinates calculation for a capacitive touch sensing device.
2. Description of the Related Art
In recent years, capacitive touch screen have been used in a large number of devices. U.S. Pat. No. 7,030,860B1 discloses a structure in which a plurality of X-electrodes aligned in an X-direction and a plurality of Y-electrodes aligned in a Y-direction are formed on a single glass substrate as a structure of the capacitive touch screen. JP2009-244958A discloses a structure of a touch sensor in which parts of liquid crystal display elements form Y-electrodes, and X-electrodes are disposed on a glass for liquid crystal display. The touch sensor disclosed in JP2009-244958A does not require the sheet only for the touch sensor. In the touch sensors disclosed in those publications, touch coordinates are obtained according to a detected signal corresponding to a variation in a mutual capacitance between the X-electrode and the Y-electrode due to a finger touch in each combination of the X-electrodes and the Y-electrodes.
As a method for obtaining the touch coordinates, for example, there is a method for obtaining, as the touched position, the centroid calculated with the detected signal as a weight at a center position of a cross portion of each combination of the X-electrodes and the Y-electrodes. The detected signal corresponding to a mutual capacitance variation in each combination of the X-electrodes and the Y-electrodes.
It is conceivable that, when the screen is touched by a finger, there are measurement portions (the cross portion of each combination of the X-electrode and the Y-electrode) in a given range where the detected signal corresponding to a variation in the mutual capacitance is obtained. On the other hand, when the finger touches an end of the above-mentioned sensing area, the detected signal which would be obtained when measurement portions are present outside of the end of the sensing area is not obtained. For that reason, in a case where the end of the sensing area is touched by the finger, a gap between touch coordinates by the centroid calculation, and the actually touched coordinates becomes larger than a case where a neighborhood of the center of the sensing area is touched. Also, a method for correcting the calculated coordinates with some calculation formula is also proposed. However, this method has a limited improvement in a precision of the coordinates.
SUMMARY OF THE INVENTION
The invention has been made in view of the above problem, and an object of the invention is to provide a technique that can identify a touched position with higher precision than a case in which a configuration of the invention is not provided.
An outline of a typical feature of the invention disclosed in the invention will be described in brief below.
(1) A touch sensing device including: a touch sensing unit that measures a value indicative of the degree of an electric influence of a touch on each of a plurality of measurement portions within a sensing area; and a coordinate calculation unit that obtains touch coordinates by calculating the optimal solution of the objective function which expresses the sum of squared differences between each of detection signal values measured at the plurality of measurement portions and each of values calculated by the function that expresses theoretical signal values of each measurement portions versus touch coordinates and touch size.
(2) The touch sensing device according to the item (1), in which the variables further includes a peak value of the function which expresses the theoretical signal values.
(3) The touch sensing device according to the item (2), in which the function is a two-dimensional Gaussian function that has a maximum point at the touch coordinates.
(4) The touch sensing device according to any one of the items (1) to (3), in which the coordinate calculation unit determines whether a first area within the sensing area is touched, or a second area closer to an end of the sensing area than the first area is touched, and the coordinate calculation unit obtains touch coordinates by calculating variables which minimize the objective function based on the difference between each of the detection signal values measured at the measurement portions and each of the values calculated by the function at the measurement portions if it is determined that the second area is touched, and obtains the touch coordinates through a calculation method different from that for the second area if it is determined that the first area is touched.
(5) The touch sensing device according to any one of the items (1) to (4), in which the coordinate calculation unit obtains the touch coordinates so that the error becomes minimal through an iterative solution technique, and the coordinate calculation unit sets the touch coordinates obtained previously as an initial value of the iterative solution technique.
(6) The touch sensing device according to any one of the items (1) to (5), further a touch sensor substrate on which the touch sensing unit and the coordinate calculation unit are mounted, and the coordinate calculation unit further includes a communication unit that transmits a signal indicative of whether to obtain the touch coordinate so that the error becomes minimal to a computer connected to the touch sensor substrate.
(7) A touch screen, comprising: a measurement unit that measures a value indicative of the degree of an electric influence of a touch on each of a plurality of measurement portions within an area where the touch is detected; a storage unit that stores a value indicative of a characteristic of a signal value due to a touch different depending a specification and an individual of the touch screen; and a communication unit that transmits a value measured at the plurality of measurement portions, and a value indicative of the characteristic stored in storage unit to a calculation unit that obtains touch coordinates by obtaining, on the basis of a function for obtaining each theoretical value of the plurality of measurement portions according to a variables including a value indicative of a characteristic of the touch screen, and a value indicative of the touch coordinates and the characteristic, a variables in which an objective function based on a difference between each of detection signal values measured at the plurality of measurement portions and each of values calculated by the function at the measurement portions is minimal to obtain the touch coordinates.
(8) A touch sensing method, including the steps of: measuring a value indicative of the degree of an electric influence of a touch on each of a plurality of measurement portions within an area where the touch is detected; and obtaining touch coordinates by obtaining, on the basis of a function for obtaining each theoretical value of the plurality of measurement portions according to a variables including the touch coordinates, a variables in which an objective function based on a difference between each of detection signal values measured at the plurality of measurement portions and each of values calculated by the function at the measurement portions is minimal.
According to the invention, when the finger touches an end of the sensing area, the touched position can be detected with higher precision than a case in which a configuration of the invention is not provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an example of configuration of a main function related to touch sensing in a touch sensitive device according to a first embodiment of the invention;
FIG. 2 is a diagram illustrating an example of a processing flow of a touch detection unit, a coordinate calculation unit, and a communication unit;
FIG. 3 is a diagram illustrating one example of detected signal values in a part of measurement portions;
FIG. 4 is a diagram illustrating another example of the detected signal values in a part of the measurement portions;
FIG. 5 is a diagram illustrating an example of a relation between coordinates of measurement portions and a function f indicative of a theoretical signal value;
FIG. 6 is a diagram illustrating an example of a relation between touch coordinates and an objective function; and
FIG. 7 is a block diagram illustrating an example of a main functional configuration related to touch sensing in a touch sensitive device according to a second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings. In the embodiments, components having the same function are denoted by identical reference characters, and their repetitive description will be omitted.
First Embodiment
FIG. 1 is a block diagram illustrating an example of configuration of a main function related to touched position detection in a device with a touch screen according to a first embodiment of the invention. The device with the touch screen is, for example, a smartphone, a tablet device, or a personal computer with a touch screen. The device with the touch screen includes a display panel DP with a touch sensor, and a host substrate HS. The display panel DP with the touch sensor is, for example, an in-cell touch screen of a liquid crystal display panel or an organic EL display panel, and a sensitive area of the touch sensor is disposed in correspondence with a display area thereof.
A plurality of X-electrodes LX and a plurality of Y-electrodes LY which are common to drive electrodes for display, an integrated circuit package IC, and a memory FM are disposed on a display panel DP with a touch sensor. The X-electrodes LX are aligned in a lateral direction, extend in a vertical direction, and are denoted by LX 1 , LX 2 , LX n from the left. The Y-electrodes LY are aligned in the vertical direction, extend in the lateral direction, and are denoted by LY 1 , LY 2 , LY m from above. For example, each of the number n of X-electrodes LX and the number m of Y-electrodes LY is about 10 to 30.
A touch detection unit MU, a coordinate calculation unit CU, a transmitting unit TU, and a panel storage unit FM are implemented in the integrated circuit package IC. The touch detection unit MU includes apart of the display control circuit, and a touch detection circuit, and is connected to the Y-electrodes LY which are common to drive electrodes for display, and the X-electrodes LX. The touch detection unit MU acquires a detected signal corresponding to a variation in each mutual capacitance of measurement portions MP which are arranged at cross points of the X-electrodes LX and the Y-electrodes LY in a matrix. The coordinate calculation unit CU is realized by a processor incorporated into the IC, and calculates coordinates (touch coordinates) indicative of a position touched by the finger according to the detected signal at each of the measurement portions MP. The calculation method will be described later. The transmitting unit TU transmits information on the calculated touch coordinates toward a host substrate HS. The panel storage unit FM is configured by a nonvolatile memory and a DRAM, and stores calculation results from the processor, and programs therein.
The host substrate HS is a type of computer, and includes a host processing unit PR and a receiving unit RU. The receiving unit RU is connected to a transmitting unit TU of the display panel DP with the touch sensor, and receives information on the touch coordinates transmitted from the transmitting unit TU. The host processing unit PR corresponds to a processor and a memory, analyzes operation of a user according to the received information on the touch coordinates and an image displayed on the screen, and instructs the overall device on the image to be displayed on the screen or a communication with an external of the device according to the operation. With the above configuration, the device with the touch screen having the host substrate HS can provide the user with the image or the information, or help the user to create various contents.
Hereinafter, a description will be given of processing of acquiring the respective touch detected signals of the measurement portions MP, and calculating the touch coordinates. FIG. 2 is a diagram illustrating an example of a processing flow of the touch detection unit MU, the coordinate calculation unit CU, and the communication unit TU. The processing illustrated in FIG. 2 is processing for obtaining the touch coordinates once, and this processing is repetitively conducted at various times with time.
First, the touch detection unit MU acquires the respective touch detected signals from the plural measurement portions MP at which the X-electrodes LX and the Y-electrodes LY cross each other (Step S 101 ). More specifically, the touch detection unit MU supplies pulse signals to the Y-electrodes LY in sequence, and measures an integral value of currents flowing into a detector circuit of the touch detection unit from the respective X-electrodes LX when supplying the pulse signals. As a result, the touch detection unit MU acquires the touch detected signal corresponding to the mutual capacitance variation of each measurement portion MP. A variation in the mutual capacitance has a tendency to become larger as a size of the finger is larger. Then, the touch detection unit MU converts an intensity of the detected signal into a digital value. This value is a detected signal value of a source for a coordinate calculation.
Then, the coordinate calculation unit CU determines whether the position touched by the user s finger is in an edge area close to any corner of a sensing area, or in a center area close to a center thereof (Step S 102 ). The center area is, for example, an area surrounded by a center line of the second X-electrode LX 2 , a center line of the (n−1) th X-electrode LX n-1 , a center line of the second Y-electrode LY 2 , and a center line of the (m−1) th Y-electrode LY m-1 . The center area may be an area at a predetermined distance from an end of the sensing area. The edge area is an area except for the center area in the sensing area. The edge area is, for example, an area including an area on an end side from the center line of the X-electrode LX 2 , an area on an end side from the center line of the X-electrode LX n-1 , an area on an end side from the center line of the Y-electrode LY 2 , and an area on an end side from the center line of the Y-electrode LY m-1 .
In Step S 102 , in order to determine whether the touched position is included in the sensing area or in the edge area, the coordinate calculation unit CU calculates tentative touch coordinates. The tentative touch coordinates represent the centroid of the detected signal values acquired in each of the measurement portions MP. The centroid is obtained assuming that the detected signal values of each measurement portion MP is a value at the coordinates of the center of this measurement portion MP. The respective measurement portions MP are numbered, and when a detected signal value at an i-th measurement portion MP is Di, and coordinates of the i-th measurement portion MP are (x i , y i ), tentative touch coordinates (Xg, Yg) are obtained by the following expression.
Xg
=
∑
i
x
i
Di
∑
i
Di
Yg
=
∑
i
y
i
Di
∑
i
Di
(
Ex
.
1
)
Then, the coordinate calculation unit CU determines whether the tentative touch coordinates are included in the center area, or in the edge area.
FIG. 3 is a diagram illustrating one example of the detected signal values in a part of measurement portions MP. In this case, a peak is present at a measurement portion MP of a position where the fourth X-electrode LX 4 and the fifth Y-electrode LY 5 cross each other. Since it is conceivable that the tentative touch coordinates calculated by the centroid fall within an area surrounded by the measurement portions MP adjacent to the measurement portion MP of that peak, the touch coordinates fall within the center area.
FIG. 4 is a diagram illustrating another example of the detected signal values in a part of the measurement portions MP. A dashed line in FIG. 4 indicates an end of the sensing area. In this drawing, a peak is present at a measurement portion MP of a position where the n-th X-electrode LX n and the fifth Y-electrode LY 5 cross each other. It is conceivable that the tentative touch coordinates by the centroid calculation are present within an area outside of the X electrode LX (n-1) . Hence, the touch coordinates fall within the edge area. In this case, the tentative touch coordinates are present inside of a real touched position.
If the tentative touch coordinates are present in the edge area of the sensing area (Y in Step S 102 ), the touch coordinates which are an estimated value of the touched position are calculated with the use of a function fitting process subsequent to Step S 103 . On the other hand, if the tentative touch coordinates are present in the center area of the sensing area (N in Step S 102 ), the coordinates of the centroid calculated as the tentative touch coordinates are determined as the touch coordinates (Step S 106 ).
In Step S 103 , the coordinate calculation unit CU allows the transmitting unit TU to transmit a flag indicating that the function fitting process is conducted to calculate the touch coordinates to the receiving unit RU. Then, the coordinate calculation unit CU acquires the characteristic parameters of the touch screen TP from the panel storage unit FM (Step S 104 ). The characteristic parameters will be described later.
Then, the coordinate calculation unit CU calculates touch coordinates (Xt*, Yt*) with the use of the function fitting. More specifically, the coordinate calculation unit CU obtains an optimal solution (Xt*, Yt*, S*) of an objective function g(Xt, Yt, S) that is a sum of squared differences between a function f expressing a theoretical signal value in each of the measurement portions MP, and a real detected signal value in each of the measurement portions MP, and sets the result as the final touch coordinates (Xt*, Yt*) (Step S 105 ). Then, the transmitting unit TU transmits the calculated or determined touch coordinates toward the receiving unit RU of the host substrate HS (Step S 107 ).
Hereinafter, processing of obtaining the touch coordinates in Step S 105 will be described in more detail. The function f expresses a detected signal corresponding to a mutual capacitance variation at a certain measurement portion MP in terms of the touch coordinates (Xt, Yt) and a virtual peak height S. The center of the measurement point is represented by coordinates (x, y). The function f is given by the following expression.
f
(
x
,
y
,
Xt
,
Yt
,
S
)
=
S
exp
{
-
(
Xt
-
x
α
(
S
)
)
2
-
(
Yt
-
y
β
(
S
)
)
2
}
(
Ex
.
2
)
A function α and a function β are approximate polynomials determined according to the specification of the display panel DP with the touch sensor. Those functions are exemplified as follows.
α( S )= A 0 +A 1 S
β( S )= B 0 +B 1 S (Ex. 3)
A 0 , A 1 , B 0 , and B 1 are characteristic parameter determined according to the specification and the individual variation of the display panel DP with the touch sensor. The characteristic parameter are determined for each specification by measurement of samples, or individually by measurement during manufacturing, and stored in the panel storage unit FM in advance. The characteristic parameter may be copied in a DRAM from a nonvolatile memory when powering on, or the characteristic parameter may be acquired from the DRAM in Step S 104 .
FIG. 5 is a diagram illustrating an example of a function f expressing value of theoretical signal values in term of coordinates (x, y) that is the center of a measurement point MP. The function f indicates a bell shape and has the maximum value S at the touch coordinates (Xt, Yt). Also, the function α and the function β indicate the degree of expansion of a hoot of a mountain of the graph.
With the use of the function f, the objective function g that is the sum of squared differences between the detection signal measured at each of the measurement portions MP, and the value calculated by the function f at each of the measurement portion MP is represented as follows.
g
(
Xt
,
Yt
,
S
)
=
∑
i
{
Di
-
f
(
xi
,
yi
,
Xt
,
Yt
,
S
)
}
2
(
Ex
.
4
)
Like the above description, Di is a real detection signal value at the i-th measurement portion MP, and (x i , y i ) is coordinates of the i-th measurement portion MP. Because values of Xt, Yt, and S are variables not determined in the function f at a present time, the objective function g can be regarded as a function of Xt, Yt, and S. The objective function g can be expressed as the sum of squared differences between the measurement value and the theoretical value at each of the measurement portions MP. The objective function g is not always limited to the above function. For example, the values may be weighted according to the positions of the measurement portions MP.
FIG. 6 is a diagram illustrating an example of a relation between the touch coordinates (Xt, Yt) and the objective function g in the objective function g(Xt, Yt, S). FIG. 6 illustrates a case in which S is a constant for ease of explanation. For example, when an influence of S is ignored, (Xt*, Yt*) at which the values of the objective function g(Xt, Yt, S) is minimum, are the touch coordinates to be calculated in FIG. 6 .
The coordinate calculation unit CU obtains the values of (Xt, Yt, S) at which the value of the objective function g is minimized through a repetitive numerical solution. For example, a non-linear least squares or a mathematical optimization.
Hereinafter, the least squares linear Taylor differential correction method which is one of the non-linear least squares will be described. This method is a numerical calculation by using a condition that the minimum value of the objective function g occurs when the gradient is zero. That is the following equations are satisfied at the minimum point of the function g.
∂
g
∂
Xt
=
0
∂
g
∂
Yt
=
0
∂
g
∂
S
=
0
(
Ex
.
5
)
Put values (Xt 0 , Yt 0 , S 0 ) are estimate of the optimal solution (Xt*, Yt*, S*) in the vicinity of a point at which the objective function g is minimum. Consider the Taylor series expansion of the function f linearized by approximation to first-order in the vicinity of the estimated value (Xt 0 , Yt 0 , S 0 ), and the conditions of Expression 5, the following simultaneous equation is obtained.
∑
i
[
∂
fi
∂
c
0
]
[
∂
fi
∂
c
0
]
T
δ
c
=
-
∑
i
[
∂
fi
∂
c
0
]
(
f
(
xi
,
yi
,
Xt
0
,
Yt
0
,
S
)
-
Di
)
Where
c
≡
[
Xt
Yt
S
]
T
c
0
≡
[
Xt
0
Yt
0
S
0
]
T
δ
c
≡
c
-
c
0
[
∂
fi
∂
c
0
]
≡
[
∂
f
(
xi
,
yi
,
c
)
∂
Xt
|
c
=
c
0
∂
f
(
xi
,
yi
,
c
)
∂
Yt
|
c
=
c
0
∂
f
(
xi
,
yi
,
c
)
∂
S
|
c
=
c
0
]
T
(
Ex
.
6
)
Those expressions are linear simultaneous equations related to δc. Therefore, δc is obtained through a Gaussian elimination method. An estimated value c 0 is replaced with c 0 +δc with the use of the obtained δc, and calculation is repeated to obtain the optimal solution (Xt*, Yt*, S*). (Xt*, Yt*) is the calculated touch coordinates. The tentative touch coordinates obtained in Step S 102 may be preferably used for an initial value of the estimated value c 0 required for a first calculation. As another method, the touch coordinates calculated in the processing of the previous Steps S 101 to S 107 may be used. This is because when a move in the touch coordinates between the previous processing and the present processing is small, a reduction in the number of repetitive processing can be expected.
The convergence condition of the repetitive calculation may be set so that ∥δc∥ is smaller than a given value. In the calculation of the touch coordinates, because a processing speed is important, there is a need to determine an upper limit of the number of repeating the above-mentioned calculation in a practical use. Hence, the number of repetitive calculations is equal to or lower than the upper limit.
The touch coordinates are thus obtained with the use of the function fitting so that the touched position can be detected with high precision even when a portion close to the end of the sensing area is touched. This is because when the function fitting is used, even if the measurement portion MP corresponding to, for example, a right side of the peak is not present, the touch coordinates can be calculated with the use of a value of the measurement portion MP corresponding to a left side of the peak, or values of the measurement portions MP corresponding to upper and lower portions of the peak.
Also, the processing load of the display panel DP with the touch sensor can be reduced by calculating the touch coordinates through the function fitting only when the touched position is close to the end. Also, in Step S 103 , information on whether the touch coordinates are calculated through the function fitting, or not, is transmitted to the host substrate HS side. This information can be recognized by a computer. Thus a program can flexibly deal a change of a time interval for acquiring the touch coordinates in case that the time interval is changed depending on whether the function fitting is conducted or not, for example, because of a limit of a calculation capacity of the coordinate calculation unit CU.
In Step S 102 , it is determined whether the function fitting is conducted, or not, according to whether the tentative touched position is in the edge area, or not. Not only that, but the determination may be conducted on the basis of the size of touch, that is, the number of responsive measurement portions MP, or whether multi-touch is made, or not. For example, in the case of a size as large as the touch screen is touched by a palm, the function f is not applied, and the fitting is difficult. Therefore, such a situation needs to be dealt with through the gravity center calculation or another algorithm. Also, since the multi-touch has a high potential not to require precision, there may arise no problem in the conventional algorithm.
Second Embodiment
FIG. 7 is a block diagram illustrating an example of a main functional configuration related to touch sensing system according to a second embodiment of the invention. The second embodiment is mainly different from the first embodiment in that the coordinate calculation unit CU is disposed on the host substrate HS side. Hereinafter, differences from the first embodiment will be mainly described.
The touch sensitive screen is equipped with a plurality of X-electrodes LX, a plurality of Y-electrodes LY, and an integrated circuit package IC. A touch detection unit MU, a transmitting unit TU, and a panel storage unit FM are included in the integrated circuit package IC. The panel storage unit FM can be configured by another package different from the integrated circuit package IC. The touch detection unit MU is connected to the X-electrodes LX and the Y-electrodes LY, and acquires a detected signal corresponding to a variation in each mutual capacitance of the measurement portions MP which are arranged at cross points of the X-electrodes LX and the Y-electrodes LY in a matrix. The panel storage unit FM is configured by a nonvolatile memory, and stores characteristic parameter used when calculating the touch coordinates therein.
The transmitting unit TU transmits the calculated measurement values of the respective measurement portions MP, and the characteristic parameter stored in the panel storage unit FM toward the host substrate HS. In the second embodiment, for making data transmission more efficient, it is preferable that the characteristic parameters are transmitted when starting the device with the touch screen.
The host substrate HS includes a host processing unit PR, a host storage unit MM, a receiving unit RU, and a coordinate calculation unit CU. The coordinate calculation unit CU is realized by processing of the same processor as that of the host processing unit PR. The receiving unit RU receives the characteristic parameters transmitted from the transmitting unit TU, and delivers the characteristic parameters to the host storage unit MM at the time of startup, and receives a detected signal value of the touch detected signal transmitted from the transmitting unit TU, and delivers the detected signal value to the coordinate calculation unit CU in a normal operation. The coordinate calculation unit CU calculates the touch coordinates on the basis of the characteristic parameters read from the host storage unit MM and the measurement value of the received touch detected signal. A method for calculating the touch coordinates is identical with that in the first embodiment, and therefore a detailed description thereof will be omitted.
In the second embodiment, the coordinate calculation unit CU is disposed on a side of the host substrate HS. In general, since an arithmetic capacity of the processor which is a main of the host substrate HS is higher than a processing capability of the processor mounted in the display panel DP with the touch sensor, a time required to acquire the touch coordinates can be reduced.
Also, when the characteristic parameters are stored in the panel storage unit FM on a side of the display panel DP with the touch sensor, and transmitted to the host substrate HS side, a difference in the characteristics caused by a manufacturing error of the display panel DP with the touch screen can be allowed. That is, a difference of the individual devices can be dealt with no need of a load of manufacturing and inspection by an excessive quality for rigidly managing the characteristics of the touch sensitive device.
While there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.
|
In a touch sensing device of a capacitive type, touch coordinates are obtained according to a detected signal corresponding to a variation in a mutual capacitance between an X-electrode and a Y-electrode due to a finger touch in each combination of a plurality of X-electrodes and a plurality of Y-electrodes within a sensing area. The theoretical value of the detected signal in each combination of the X-electrodes an the Y-electrodes approximately expressed by a two-dimensional Gaussian function. The touch coordinates are identified correctly by finding the optimal solution of the object function which expresses the sum of squared differences between each of the theoretical signal value and the detected signal value.
| 6
|
RELATED APPLICATION(S)
[0001] This application claims the benefit under 35 USC § 119(e) of Korean Patent Application No. 10-2005-0129865 filed Dec. 26, 2005, which is incorporated herein by reference in its entirety.
FIELD OF INVENTION
[0002] The present invention relates to a semiconductor device and a method for manufacturing the same.
BACKGROUND OF THE INVENTION
[0003] In general, there has been a rapid change toward high performance in next generation semiconductor devices. As a result, a via hole size has become reduced and the aspect ratio thereof has become increased. Thus, superior step coverage, via filling capability and high speed operation of a device has become necessary. To this end, a method for forming a metal interconnection on a damascene pattern using copper has been suggested as a useful method. As an example of conventional methods for forming copper interconnection, there is a method including the steps of forming a diffusion barrier layer and a seed layer for forming copper through physical vapor deposition, forming a copper interconnection layer on the seed layer through electroplating to fill a via with the copper interconnection, and performing chemical mechanical polishing. FIGS. 1 to 3 are sectional views representing a method for forming a metal interconnection of a semiconductor device according to the related art.
[0004] First, referring to FIG. 1 , after an interlayer dielectric layer 30 is formed on a semiconductor substrate 10 having a conductive layer 20 thereon, a hole 40 is formed by partially etching the interlayer dielectric layer 30 .
[0005] Then, referring to FIG. 2 , a diffusion barrier layer 50 and a seed layer 60 including copper are sequentially stacked in the hole 40 and on the surface of the interlayer dielectric layer 30 .
[0006] In detail, the seed layer 60 and the diffusion barrier layer 50 are formed through a PVD (Plasma Vapor Deposition) process. However, a reduction of the via size and an increase of the step difference may cause a poor step coverage, so that overhang A or a deposition discontinuous point B may occur.
[0007] Referring to FIG. 3 , a copper interconnection layer 70 is deposited on the seed layer 60 through electroplating so as to fill the hole 40 .
[0008] However, a void C is formed in the hole 40 due to the overhang A and the deposition discontinuous point B. As described above, according to the related art, the overhang, the deposition discontinuous point and voids cause the increase of the contact resistance so that the reliability of the semiconductor device is reduced.
[0009] Further, according to the related art, such overhang, deposition discontinuous point and voids may become serious problems because the aspect ratio of the hole may increase as the degree of integration of the semiconductor device increases.
BRIEF SUMMARY
[0010] Embodiments of the present invention can solve the above problems occurring in the prior art. An embodiment of the present invention can provide a semiconductor device and a method for manufacturing the same, capable of preventing an overhang or a void from being generated due to a step difference in the process of forming a diffusion barrier layer and a seed layer.
[0011] Another embodiment of the present invention is to provide a semiconductor device and a method for manufacturing the same, capable of preventing the performance degradation of the semiconductor device caused by an overhang or a void, thereby preventing the reliability of the semiconductor device from being degraded.
[0012] To achieve the above, embodiments of the present invention provide a semiconductor device comprising: a semiconductor substrate having a conductive layer; an interlayer dielectric layer formed on the semiconductor substrate and provided with a hole having a tapered angle on the upper portion; a diffusion barrier layer formed on the hole and the interlayer dielectric layer; and a seed layer formed on the diffusion barrier layer.
[0013] Another aspect of the present invention provides a method comprising: forming an interlayer dielectric layer on the semiconductor substrate having a conductive layer; forming a first photoresist layer having a predetermined thickness on the interlayer dielectric layer; exposing an entire surface of the first photoresist layer; forming a shielding layer on the exposed first photoresist layer; forming and patterning a second photoresist layer on the shielding layer; etching the shielding layer exposed by the patterned second photoresist layer; developing and removing a predetermined portion of the first photoresist layer which is exposed by the etched shielding layer; and forming a hole by etching the interlayer dielectric layer exposed by the removal of the predetermined portion of the first photoresist layer.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIGS. 1 to 3 are sectional views illustrating a method for forming a metal interconnection of a semiconductor device according to the related art; and
[0015] FIGS. 4 to 12 are sectional views illustrating a method for manufacturing a semiconductor device according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Hereinafter, a semiconductor device and a method for manufacturing the same according to an exemplary embodiment of the present invention will be explained in detail with reference to accompanying drawings.
[0017] In the following description, the expression “formed on each layer” may include the meaning of both “formed directly on each layer” and “formed indirectly on each layer”.
[0018] FIGS. 4 to 12 illustrate a method for forming a metal interconnection of a semiconductor device in accordance with an exemplary embodiment of the present invention.
[0019] Referring to FIG. 4 , an interlayer dielectric layer 120 is formed on a semiconductor substrate 100 where a conductive layer 110 is formed.
[0020] Then, referring to FIG. 5 , a photoresist is coated on the interlayer dielectric layer 120 to a predetermined thickness so as to form a first photoresist layer 130 . The first photoresist layer 130 can have a thickness such that the width of the undercut portion can be controlled.
[0021] In a specific embodiment, the first photoresist layer 130 can have a thickness within a range of about 50 nm to about 200 nm. That is, when the thickness of the first photoresist layer 130 is less than 50 nm, an undercut hardly occurs, and when the thickness of the first photoresist layer 130 exceeds 200 mm, the undercut excessively occurs so that a taper angle of the interlayer dielectric layer 120 is excessively increased.
[0022] For instance, according to an embodiment of the present embodiment, an undercut having a proper size may be obtained by forming the first photoresist layer 130 with a thickness of about 100 nm.
[0023] Subsequently, a blank exposure process can be performed to expose the entire surface of the first photoresist layer 130 to light without using a photo mask.
[0024] Then, referring to FIG. 6 , a shielding layer 140 can be formed on the first photoresist layer 130 .
[0025] The shielding layer 140 functions to protect the first photoresist layer 130 except for the regions of the first photoresist layer 130 exposed in a subsequent process from making contact with a developer.
[0026] In one embodiment a middle metal layer formed by depositing a metal can be used as the shielding layer 140 . However, the present invention is not limited thereto. That is, in other embodiments, an insulating layer such as an oxide layer or a nitride layer can be used as the shielding layer 140 .
[0027] The middle metal layer 140 can be deposited through PVD (Physical Vapor Deposition) or CVD (Chemical Vapor Deposition).
[0028] In a specific embodiment, the middle metal layer 140 can be aluminum deposited on the first photoresist layer 130 through CVD.
[0029] The middle metal layer 140 can support a second photoresist layer 150 , described below, and serves as a mask when removing the first photoresist layer 130 .
[0030] Referring to FIG. 7 , a second photoresist layer 150 can be formed on the middle metal layer 140 and patterned for forming a trench.
[0031] For example, the second photoresist layer 150 can be exposed to light through a predetermined photo mask so that the second photoresist layer 150 is patterned on the middle metal layer 140 . Accordingly, a predetermined portion of the middle metal layer 140 is exposed.
[0032] Then, referring to FIG. 8 , the exposed middle metal layer 140 can be etched so that a predetermined portion of the first photoresist layer 130 is exposed.
[0033] In this case, a wet etching process or a dry etching process can be used as a method for etching the middle metal layer 140 .
[0034] In one embodiment, the exposed middle metal layer 140 can be etched through RIE (Reactive Ion Etch).
[0035] A predetermined portion of the first photoresist layer 130 positioned under the middle metal layer 140 is exposed as the predetermined portion of the middle metal layer 140 is removed.
[0036] Then, referring to FIG. 9 , the exposed first photoresist layer 130 can be developed.
[0037] Since the first photoresist layer 130 is blank-exposed in the previous process, the undercut, which is sunk in at a predetermined angle and removed, may occur as the exposed portion of the first photoresist layer 130 is developed.
[0038] As the first photoresist layer 130 has been partially undercut, overhang can be prevented from being generated in the following process of forming the diffusion barrier layer 170 and the seed layer 180 .
[0039] Referring to FIG. 10 , as the exposed portion of the first photoresist layer 130 is removed, a predetermined portion of the interlayer dielectric layer 120 can be exposed. The exposed portion of the interlayer dielectric layer 120 can be etched so as to form a hole 160 for the interconnection between layers. Accordingly, a predetermined portion of the conductive layer 110 is exposed.
[0040] The hole 160 can be formed as a trench, a via hole or a contact hole depending on the desired application.
[0041] In an embodiment, a wet etching process or a dry etching process can be used for etching the interlayer dielectric layer 120 . The interlayer dielectric layer 120 can be etched such that the hole 160 is formed therein, and the upper portion thereof is sunk at a predetermined angle.
[0042] In this case, the upper portion of the hole 160 has a width wider than the width of the lower portion of the hole 160 .
[0043] If the interlayer dielectric layer 120 is etched through the dry etching process, the lower portion of the hole 160 can have a width identical to a width of a middle portion of the hole 160 , and the upper portion of the hole can have a width wider than the width of the lower portion of the hole.
[0044] That is, according to the exemplary embodiment of the present invention, since the lower portion of the first photoresist layer 130 formed on the interlayer dielectric layer 120 is undercut to be sunk at a predetermined angle, the etching rate may increase at the upper portion of the interlayer dielectric layer 120 . Accordingly, after the etching process has been performed, the hole 160 is formed in the interlayer dielectric layer 120 and the upper portion of the interlayer dielectric layer 120 is sunk at a predetermined angle.
[0045] The upper portion of the interlayer dielectric layer 120 and the lower portion of the first photoresist layer 130 , being sunk in at predetermined angles, form sink parts 161 .
[0046] Referring to FIG. 11 , the first photoresist layer 130 , the middle metal layer 140 and the second photoresist layer 150 can be removed leaving a hole 160 in the interlayer dielectric layer 120 having a tapered angle at the upper portion of the hole 160 .
[0047] Referring to FIG. 12 , a diffusion barrier layer 170 and a seed layer 180 can be sequentially stacked on the interlayer dielectric layer 120 .
[0048] The diffusion barrier layer 170 prevents a metal interconnection layer to be filled in the hole in the following process from diffusing into the interlayer dielectric layer 120 , and the seed layer 180 accelerates the growth of the metal interconnection layer.
[0049] In detail, the diffusion barrier layer 170 can be formed on the interlayer dielectric layer 120 and the exposed portion of the conductive layer 110 , and the seed layer 180 can be formed on the diffusion barrier layer 170 .
[0050] The diffusion barrier layer 170 may be formed of a single TaN layer, a single Ta layer, or a dual TaN/Ta layer.
[0051] Referring to FIG. 12 , the diffusion barrier layer 170 may include a dual layer of TaN/Ta 171 and 172 .
[0052] Since the upper portion of the interlayer dielectric layer 120 is chamfered at a predetermined angle, the diffusion barrier layer 170 and the seed layer formed on the interlayer dielectric layer 120 are also chamfered at a predetermined angle.
[0053] Accordingly, the overhang does not occur in the process of forming the diffusion barrier layer 170 and the seed layer 180 so a void which may generate in the metal interconnection layer to be filled in the hole 160 can be prevented. After forming the diffusion barrier layer 170 and the seed layer 180 , a process of forming the metal interconnection layer can be performed to interconnect the layers.
[0054] Embodiments of the present invention can be applied to both single damascene process and dual damascene process, and can be applied to the process for forming the contact hole and the via hole.
[0055] The semiconductor device and the method for manufacturing the same according to the exemplary embodiment of the present invention can prevent an overhang from being generated due to a step difference of a hole in the process of forming a diffusion barrier layer and a seed layer.
[0056] Further, according to embodiments of the present invention, the performance degradation of the semiconductor device caused by an overhang or a void can be prevented, so that the reliability of the semiconductor device can be improved.
[0057] The embodiments and the accompanying drawings illustrated and described herein are intended to not limit the present invention, and it will be obvious to those skilled in the art that various changes, variations and modifications can be made to the present invention without departing from the technical spirit of the invention.
|
A semiconductor device and a method for manufacturing the same is provided. The semiconductor device includes a semiconductor substrate having a conductive layer; an interlayer dielectric layer formed on the semiconductor substrate, the interlayer dielectric layer having a hole with a taper angled at the hole's upper portion; a diffusion barrier layer formed on the hole and the interlayer dielectric layer; and a seed layer formed on the diffusion barrier layer.
| 7
|
FIELD OF THE INVENTION
[0001] This invention relates to an gel for skin treatment and preparation method for the same, and more particularly to an Shiunko nanomicell for skin treatment and preparation method for the same.
BACKGROUND OF THE INVENTION
[0002] Shiunko is a Chinese traditional ointment used for treating burns and scalds, and mainly consists of Lithospermum Radix, Angelica Radix, Sesame oil, and Wax. The effective components of Lithospermum Radix includes shikonin and the derivatives thereof, which have been proved having the functions of granulation tissue formation improving, anti-inflammatory, fasting the wound healing, anti-bacteria, and anti-tumor. Shiunko also has the advantages of cheap price and easy preparation. However, Shiunko also has the deficiencies of being easy denaturalized under room temperature, thick sesame smell, oily sensation, hard to cleaning so that it is inconvenient in clinical use.
[0003] Silver sulfadiazine 1% cream is the major agent used to treat burns and scalds in western medicine from 1968, and silver sulfadiazine has the function of inducing the cell wall deformation of the bacteria, damaging the cell membrane so that it can kill the bacteria. However, the silver granules will deposit in skin dermis to cause Argyrai, and in monolayer culture, the silver ions and the sulfadiazine are even found having a high toxicity in keratinocytes and fibroblasts, which is harmful to wound healing. Further, the toxic dose and the sterilization dose of the silver ions are similar, and hence the normal cells will be damaged when the bacteria are killed. In addition, sulfadiazine will also inhibit the bone marrow function and induce allergy.
[0004] The technology of nanomicell is developed recently, which is a concentrated solution of phospholipids and certain solvents such as a glycerin or a Propylene Glycol. The nanomicell can dissolve the oil and substances that are difficult to be dissolved in water under room temperature (25° C.-60° C.). The concentrated solution will form numerous liposomes if diluted with water, and hence the nanomicell means a transparent and concentrated solution that includes the lipid-soluble drugs packaged with phospholipids and water to form numerous micells. The nanomicell has advantages of well stability, high hydrophile, safety in physiology, no irritation, no synthesized detergent and preservative using, and even can improve the absorption of active components and bio-availability. The nano-sized micells can pass through the cell membrane by cell fusion, endocytosis or phagocytosis, and hence are suitable as the excipient in cosmetic, pharmaceutical or biomedical research. Further, the micell have a diameter less than 100 nanometers can be absorbed by skin, which is an ideal transdermal drug delivery method that is efficient and not invasive.
[0005] U.S. Pat. No. 6,468,553 and Taiwan Pat. No. I226,838 have made efforts on the oil substrate of the traditional Shiunko, but the deficiencies of oily sensation and hard to cleaning still exist. Further, the improvement in prior art maybe prolong the storage time under room temperature, but has no amelioration in transdermal ability.
[0006] In order to overcome the drawbacks in the prior art, an Shiunko nanomicell for skin treatment is provided. The particular design in the present invention not only solves the problems described above, but also is easy to be implemented. Thus, the invention has the utility for the industry.
SUMMARY OF THE INVENTION
[0007] It is an aspect of the present invention to provide a nanomicell for a skin, and the nanomicell includes an oil substance, an extract of a Angelica Radix, an extract of a Lithospermum Radix, and a phospholipid layer. The extract of a Angelica Radix is formed by extracting the Angelica Radix with the oil substance, and the extract of a Lithospermum Radix is formed by extracting the Lithospermum Radix with the oil substance. The extract of the Angelica Radix and the extract of the Lithospermum Radix are packaged within the phospholipid layer to form a plurality of micells having a diameter of nano-level.
[0008] Preferably, the oil substance is one selected from a group consisting of a sesame oil, a mineral oil, and an olive oil.
[0009] Preferably, the micell further includes an agueous layer outside the phospholipids layer.
[0010] Preferably, the micell has a diameter lesser than 100 nanometers.
[0011] Preferably, the nanomicell is used for a treatment for one selected from a group consisting of wound injury, burn injury, dry skin, fissure, frostbite, ulcer, and proliferate skin diseases.
[0012] It is another aspect of the present invention to provide a nanomicell gel for a skin treatment. The nanomicell gel includes an excipient that has a plurality of micells distributed therein. Further, each of the plurality of micells includes an oil extract of Angelica Radix, an oil extract of Lithospermum Radix, and a phospholipid layer. The phospholipid layer wraps therewithin the oil extract of Angelica Radix and the oil extract of Lithospermum Radix.
[0013] Preferably, the phospholipids layer includes a glycerin and a phospholipids.
[0014] Preferably, each of the plurality of micells further includes a aqueous layer outside the phospholipid layer.
[0015] Preferably, the excipient is selected from one of a gel and a hydrophilic ointment.
[0016] Preferably, each of the plurality of micells has a diameter lesser than 100 nanometers.
[0017] Preferably, the nanomicell gel is used for a treatment for one selected from a group consisting of wound injury, burn injury, dry skin, fissure, frostbite, ulcer, and proliferate skin diseases.
[0018] It is further another aspect of the present invention to provide a method of forming a nanomicell for a skin. The method includes steps of (a) extracting an Angelica Radix and a Lithospermum Radix with an oil substance to obtain an extract; (b) adding a phospholipid and a water into the extract; (c) stirring the extract in a relatively high speed and relatively high pressure condition to homogenize the extract; and (d) filtrating the extract.
[0019] Preferably, the method further includes a step of soaking the Angelica Radix in the oil substance for 24 hours before the step of extracting an Angelica Radix and a Lithospermum Radix.
[0020] Preferably, the method further includes a step of heating the oil substance to a temperature between 130° C. and 140° C. to exact the Angelica Radix and the Lithospermum Radix.
[0021] Preferably, the step (d) is carried out by a filter having a pore size below 0.1 μm.
[0022] Preferably, the oil substance is one selected from a group consisted of a sesame oil, a mineral oil, and an olive oil.
[0023] Preferably, the method further includes a step of add a excipient to the extract after the step of filtrating the extract.
[0024] Preferably, the excipient is one selected from a gel and a hydrophilic ointment.
[0025] The above aspects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a polygon illustrating the variation in particle size of the different nanomicells after different storage times according to the embodiment of the present invention;
[0027] FIG. 2(A) is a diagram showing the bacterial culture results of Pseudomonas aeruginosa after 0, 8, and 24 hours of culture with no drugs (control group)(a), silver sulfadiazine 1% cream(b), or traditional Shiunko(c) respectively according to the embodiment of the present invention;
[0028] FIG. 2(B) is a diagram showing the bacterial culture results of Pseudomonas aeruginosa after 0, 8, and 24 hours of culture with SSN(d), OSN(e) or MSN(f) respectively according to the embodiment of the present invention;
[0029] FIG. 3 is a diagram showing the wounds of the experimental rabbits at the time of 31 days after the burn injury and successive treatment of no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e), and MSN(f) respectively according to the embodiment of the present invention, (and the circle area points out the original scald wound);
[0030] FIG. 4 is a diagram showing the wounds of the experimental rabbits at the time of 37 days after the burn injury and successive treatment of no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e), and MSN(f) respectively according to the embodiment of the present invention (the circle area means the original scald wound); and
[0031] FIGS. 5 (A)-(F) are diagrams showing wound tissue sections in LM 20× after stained with Hematoxylin & Eosin at the time of 20 days after the burn injury and successive treatment of no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e), and MSN(f) respectively according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] The invention is described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for the purpose of illustration and description only; it is not intended to be exhaustive or to be limited to the precise form disclosed.
[0033] The Lithospermum Radix used in the following experiments is Arnebia euchroma, and the Angelica Radix is the dry roots of Angelica sinensis (Oliv.) Diels. The preparing method of different Shiunko Nanomicells will be introduced first, and then the creativeness of the Shiunko Nanomicells will be showed by different function testing experiments.
The Preparing Methods of Shiunko Oils Containing Different Oil Substance
[0034] The materials in S group include: Lithospermum Radix 90 gm, Angelica Radix 90 gm, and sesame oil 300 gm. The materials in group 0 includes: Lithospermum Radix 90 gm, Angelica Radix 90 gm, and olive oil 300 gm, and the materials in group M includes: Lithospermum Radix 90 gm, Angelica Radix 90 gm, and mineral oil 300 gm. The preparing method of Shiunkos include steps of: first, purifying the Angelica Radix by eliminating the impurities, and then soaking the Angelica Radix in different oil substances as listed above. After 24 hours, the oil substances containing Angelica Radix are heated to a temperature between 130° C. to 140° C. until Angelica Radix has a scorched surface, and then adding Lithospermum Radix to the oil substances and keeping in the same temperature for 15 minutes. Second, when the oil substances having a red color, heating is stopped, and then Angelica Radix and Lithospermum Radix are removed from the respective oil substances. Finally, the oil substance and the extract of Angelica Radix and Lithospermum Radix therein are filtered with 4 layers of sterile swabs respectively, and then the respective filtrates are stored in different glass bottles.
The Preparing Methods of Shiunko Nanomicells
[0035] The materials include: the Shiuriko oils sampled from the group S, the group O and the group M respectively, and further includes glycerin, phospholipids and pure water. The steps of the preparing methods include: First, adding the phospholipids into the samples S, O, and M respectively, and stirring uniformly to get respective mixtures. Second, the respective mixtures above are added into the glycerin respectively and stirred, and then the pure water is also added into. After high speed stirred in homogenizer (6000 rpm, 3 minutes), the respective mixtures are homogenized in high pressure homogenizer, and filtered with 0.1 g/m filter membrane. Finally, the condensed solutions of a sesame Shiunko nanomicell (group S), olive Shiunko nanomicell (group 0), and mineral Shiunko nanomicell (group M) having a red color are collected respectively.
The Preparing Methods of Shiunko Nanomicell Gels
[0036] The Shiunko nanomicell gels could be made by mixing 100 ml of respective Shiunko nanomicells mentioned above with 100 gm of transparent gel (Lubrajel DV), and then stored in bottles.
Function Test I: Particle Size Analysis
[0037] Drops of sesame Shiuriko nanomicell(SSN), olive Shiunko nanomicell(OSN), and mineral Shiuriko nanomicell(MSN) are sampled respectively, and diluted in 100 ml of pure water to form diluents respectively. After stirring homogeneously, drops of the respective diluents are sampled and analyzed by a particle size analyzer (Beckman Coulter™N5). The results are showed in table 1.
[0000]
TABLE 1
SSN
OSN
MSN
Day 1
66.6 ± 25.8 nm
80.5 ± 25.5 nm
70.8 ± 27.7 nm
Day 20
99.0 ± 31.6 nm
79.1 ± 25.0 nm
44.7 ± 20.4 nm
Day 30
78.7 ± 27.5 nm
91.2 ± 30.5 nm
75.8 ± 26.7 nm
Day 40
71.9 ± 22.4 nm
78.3 ± 23.4 nm
80.1 ± 24.6 nm
Day 50
76.2 ± 22.7 nm
80.7 ± 26.9 nm
92.9 ± 31.2 nm
Day 60
73.4 ± 29.4 nm
90.2 ± 30.9 nm
66.4 ± 23.2 nm
Day 150
86.9 ± 40.9 nm
89.1 ± 28.8 nm
84.0 ± 24.6 nm
[0038] Please also refer to FIG. 1 , which is a polygon illustrating the variation in particle size of the different nanomicells after different storage times according to the embodiment of the present invention. As FIG. 1 shows, SSN, OSN and MSN all have a particle size below 100 nm, which are stable even stored under the room temperature for 150 days.
Function Test II: Anti-Bacteria Test
[0039] The bacteria tested in the present invention include Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis, Proteus mirabilis and Acinetobacter baumannii, which are usually discovered in wounds of scalds and burns. The bacteria tested in the present invention are showed in table 2.
[0000]
TABLE 2
Bacteria
No.
Pseudomonas aeruginosa
NCTC 10662
Escherichia coli
ATCC 35218
Enterococcus faecalis
ATCC 29212
Proteus mirabilis
ATCC 7002
Acinetobacter baumannii
ATCC 19606
[0040] 10 μl of respective bacteria fluids of above-mentioned bacteria, of which the total number of bacteria are 10 4 to 10 5 , are sampled and mixed with 1 ml of Tryptic Soy Broth containing no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN, OSN, and MSN respectively, and stirred homogeneously in respective bottles. After 0 minute, 8 hours and 24 hours of culture, 10 μl of culture medium are sampled from the respective bottles, and plated on Horse Blood Agar to subculture in 35° C. for 24 hours. The growing conditions are recorded and the colony forming units are calculated.
[0041] The calculated results of respective bacteria are showed in Table 3 to Table 7. Please also refer to FIGS. 2 (A)(B), which are diagrams showing the bacterial culture results of Pseudomonas aeruginosa after 0, 8, and 24 hours of culture with no drugs (control group)(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e) or MSN(f) respectively according to the embodiment of the present invention. Accordingly, the nanomicells provided according to the preferred embodiment of the present invention are actually have the ability in inhibition of Pseudomonas aeruginosa growing, while Pseudomonas aeruginosa is the commonest bacteria existed in wounds of burns and scalds and can easily induce Bacteremia that has a high fatality rate. The detail results are introduced as follows:
[0000] (I) Pseudomonas aeruginosa
[0042] The calculating results of colony forming units of Pseudomonas aeruginosa are showed in table 3.
[0000]
TABLE 3
the colony forming units of NCTC 10662 Pseudomonas aeruginosa
silver
control
sulfadiazine
traditional
group
1% cream
Shiunko
SSN
OSN
MSN
0 hours
>10 5
>10 5
>10 5
>10 5
>10 5
>10 5
8 hours
>10 5
0
>10 5
5
10
26
24 hours
>10 5
0
>10 5
0
0
0
[0043] As the table shows, first, in silver sulfadiazine 1% cream treating group, after 0, 8, and 24 hours of culture, the colony forming units are more than 10 5 , 0, and 0 respectively, which shows the silver sulfadiazine 1% cream has a great ability in inhibition of Pseudomonas aeruginosa . Second, in the traditional Shiunko treating group, the colony forming units calculated show that the traditional Shiunko has no ability in inhibition of Pseudomonas aeruginosa . Third, in the SSN treating group, after 0, 8, and 24 hours of culture, the colony forming units are more than 10 5 , 5 and 0 respectively, which shows the SSN has a good ability in inhibition of Pseudomonas aeruginosa . Fourth, in the OSN treating group, after 0, 8, and 24 hours of culture, the colony forming units are more than 10 5 , 10 and 0 respectively, which shows the SSN has a good ability in inhibition of Pseudomonas aeruginosa . Fifth, in the MSN treating group, after 0, 8, and 24 hours of culture, the colony forming units are more than 10 5 , 26 and 0 respectively, which shows the SSN has a good ability in inhibition of Pseudomonas aeruginosa.
[0000] (II) Escherichia coli
[0044] The calculating results of colony forming units of Escherichia coli are showed in table 4.
[0000]
TABLE 4
the colony forming units of ATCC 35218 Escherichia coli
silver
control
sulfadiazine
traditional
group
1% cream
Shiunko
SSN
OSN
MSN
0 hours
>10 5
>10 5
>10 5
>10 5
>10 5
>10 5
8 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
24 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
[0045] As the table shows, first, the silver sulfadiazine 1% cream has a great ability in inhibition of Pseudomonas aeruginosa . Second, the traditional Shiunko has no ability in inhibition of Escherichia coli . Third, the SSN, OSN, and MSN have no ability in inhibition of Escherichia coli.
[0000] (II) Enterococcus faecalis
[0046] The calculating results of colony forming units of Enterococcus faecalis are showed in table 5.
[0000]
TABLE 5
the colony forming units of ATCC 29212 Enterococcus faecalis
silver
control
sulfadiazine
traditional
group
1% cream
Shiunko
SSN
OSN
MSN
0 hours
>10 5
>10 5
>10 5
>10 5
>10 5
>10 5
8 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
24 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
[0047] As the table shows, first, the silver sulfadiazine 1% cream has a great ability in inhibition of Enterococcus faecalis . Second, the traditional Shiunko has no ability in inhibition of Enterococcus faecalis . Third, the SSN, OSN, and MSN have no ability in inhibition of Enterococcus faecalis.
[0000] (IV) Proteus mirabilis
[0048] The calculating results of colony forming units of Proteus mirabilis are showed in table 6.
[0000]
TABLE 6
the colony forming units of ATCC 7002 Proteus mirabilis
silver
control
sulfadiazine
traditional
group
1% cream
Shiunko
SSN
OSN
MSN
0 hours
>10 5
>10 5
>10 5
>10 5
>10 5
>10 5
8 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
24 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
[0049] As the table shows, first, the silver sulfadiazine 1% cream has a great ability in inhibition of Proteus mirabilis . Second, the traditional Shiuriko has no ability in inhibition of Proteus mirabilis . Third, the SSN, OSN, and MSN have no ability in inhibition of Proteus mirabilis.
[0000] (IV) Acinetobacter baumannii
[0050] The calculating results of colony forming units of Acinetobacter baumannii are showed in table 7.
[0000]
TABLE 7
the colony forming units of ATCC 19606 Acinetobacter baumannii
silver
control
sulfadiazine
traditional
group
1% cream
Shiunko
SSN
OSN
MSN
0 hours
>10 5
>10 5
>10 5
>10 5
>10 5
>10 5
8 hours
>10 5
0
>10 5
>10 5
>10 5
>10 5
24 hours
>10 5
0
>10 5
120
140
>10 5
[0051] As the table shows, first, the silver sulfadiazine 1% cream has a great ability in inhibition of Acinetobacter baumannii. Second, the traditional Shiunko has no ability in inhibition of Acinetobacter baumannii. Third, the SSN, OSN, and MSN have a bad ability in inhibition of P Acinetobacter baumannii.
Function Test III: Evaluation of Treating Effects in Burns and Scalds Injury
[0052] The experimental animals are twelve rabbits (male, New Zealand Rabbit), and the experiment is implemented in the Lab of Experimental Animal of Kaohsiung Medical University.
[0053] (I) Burn and Scald Model building
[0054] First, the experimental rabbits were washed with non-antibacterials soaps, and the dorsal fur was shaved off to expose the skin. Second, the rabbits are anaesthetized with ketamine 40 mg/kg i.m. Third, the twelve rabbits are divided into 6 groups (rabbits A, B are group 1; rabbits C, D are group 2; rabbits E, F are group 3; rabbits G, H are group 4; rabbits I, J are group 5; rabbits K, L are group 6,) and the predetermined injury regions of each rabbits are the same. Fourth, after heated in hot water having a temperature of 95° C. for 5 minutes, a iron column having a diameter of 2 cm is used to contact the exposed skin to produce 6 wounds respectively. After removing the iron and cooling the injury regions in room temperature for 10 minutes, the injury regions are treated with the different ointments or gels (the control group, the silver sulfadiazine 1% cream, the traditional Shiunko, the SSN gel, the OSN gel, and the MSN gel) clockwise in each group, and finally the transparent dressings (Tegaderm™) are put on each wounds respectively. Fifth, after recovering from anesthetization, the experimental rabbits are raised in normal condition. The ointments (or gels) and the dressings are replaced daily, and the wounds are recorded by photograph too. Sixth, from the time of 31 days after the injury, the ointments (or gels) and the dressings are replaced and the wounds are recorded every two days until all the rabbits heal. Seventh, after each treating, the rabbits are forced to wear special neck masks designed for preventing the rabbits licking the wounds. Eighth, the rabbits are sacrificed respectively at the time of 5, 10, 15, 20, 25 and 30 days after the injury, and the skin of the wound is took off by scissors and soaked in 10% Formalin. The tissue pathological variations of the skin are diagnosed under the direction of the pathological medicine specialist. Ninth, the 36 wounds of the other six rabbits are treated until healing, and the cutaneous wound regeneration and repair are observed and recorded.
(II) Pathological Sections Preparing
[0055] The rabbits are sacrificed, and the wound tissues are sampled 3 cm×3 cm followed by soaking in 10% Fommalin. After dehydration, defatting and embedding, 3˜6 μm wound tissue sections are prepared by microtome and fixed on slides. After stained with Hematoxylin & Eosin, the wound tissue sections are observed by light microscope. Further, the tissue pathological variation are evaluated and scored depend on eight histomorphologic features of Hyperkeratosis, Epidermal hyperplasia, Hair follicles, Apocrine glands, Smooth muscles, Fibroplasia, Vascular proliferation and Collagen orientation respectively (Adam J. Singer et al., 2000).
[0056] (III) the Cutaneous Wound Regeneration and Repair Score Results
[0057] The cutaneous wound regeneration and repair are scored by the following standard:
[0000] 5 points: the scabs have came off, and the wounds have healed, and the healing area is flat;
4 points: the scabs have came off, and the wounds have healed, and the healing area is raised;
3 points: the scabs have came off, and the wounds have not healed;
2 points: the scabs have formed over the wounds, and there is no exudate;
1 point: the scabs have formed over the wounds partially, and there is exudate sting.
[0058] The cutaneous wound regeneration and repair are scored at the time of 31 and 37 days after the injury, and the more points scored, the more well healing effects are evaluated. The cutaneous wound regeneration and repair scores are showed in tables 8 and 9.
[0000]
TABLE 8
silver
traditional
control
sulfadiazine 1%
Shiunko
Day 31
group
cream
ointment
SSN gel
OSN gel
MSN gel
rabbit A
2
2
2
1
2
2
rabbit B
1
3
2
2
2
2
rabbit H
1
3
2
2
5
2
rabbit J
2
2
2
4
5
2
rabbit K
2
2
2
4
5
5
rabbit L
2
2
2
4
2
2
total
10
14
12
18
23
15
mean
1.67 ± 0.52
2.33 ± 0.52
2 ± 0
2.83 ± 1.33
3.50 ± 1.64
2.50 ± 1.22
[0000]
TABLE 9
silver
traditional
control
sulfadiazine 1%
Shiumko
Day 37
group
cream
ointment
SSN gel
OSN gel
MSN gel
rabbit A
2
2
3
3
4
5
rabbit B
3
3
2
2
2
3
rabbit H
3
3
2
4
5
4
rabbit J
3
4
4
5
5
5
rabbit K
3
3
2
5
5
5
rabbit L
3
4
4
4
5
4
total
17
19
17
23
26
26
mean
2.83 ± 0.41
3.17 ± 0.75
2.83 ± 0.98
3.87 ± 1.17
4.33 ± 1.21
4.33 ± 0.81
[0059] Please also refer to FIGS. 3 and 4 , which are diagrams showing the wounds of the experimental rabbits at the time of 31 and 37 days after the burn injury and continuing treatment of no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e), and MSN(f) respectively according to the embodiment of the present invention, no matter at 31 or 37 days, the scores of the wounds treated with SSN, OSN and MSN are better than other groups. Further, the cutaneous wound regenerating and repairing abilities of OSN and MSN are a bit better than SSM based on the scores of the time of 37 days, and OSM has a better ability in reducing the scar tissues.
[0060] On the other hand, the traditional Shiunko is prepared based on the wax, which has the disadvantages of hard-to-clean, being painful when replacing the dressings, and being disagreeable to the sight because of the residue having a red-purple color. However, all the disadvantages are overcomed by replacing the dressings with SSN, OSN or MSN gels.
[0061] (IV) the Tissue Pathological Variation
[0062] Please refer to table 11, which is a Histomorphologic Scale of the rabbit I at the time of day 5 after the injury.
[0000]
TABLE 11
Histomorphologic Scale (Parameters and Scores) Day 5 (rabbt“I”)
Hyper-
Epidermal
Apocrine
smooth
vascular
keratosis
hyperplasia
Hair follicles
glands
muscles
Fibroplasia
proliferation
no
yes
no
yes
no
yes
no
yes
no
yes
no
yes
no
yes
collagen orientation
parameters
(1)
(0)
(1)
(0)
(1)
(0)
(1)
(0)
(1)
(0)
(1)
(0)
(1)
(0)
3
2
1
0
total
control
1
1
1
0
1
0
1
1
3: Normal
6
group
2: Abnormal
silver
1
1
1
0
1
0
0
1
collagen in
5
sulfadiazine
papillary
1% cream
dermis
traditional
1
1
1
0
0
0
0
1
1: Abnormal
4
Shiunko
collagen in
ointment
upper
SSN gel
1
1
1
0
1
0
0
2
reticular
6
OSN gel
1
1
1
0
0
0
0
1
dermis only
4
MSN gel
1
1
1
0
1
1
1
2
0: Abnormal
8
collagen in
upper and
lower half
of reticular
dermis
[0063] The scores are from 0 point of worst condition to 10 points of almost normal skin. The wound tissue sections are evaluated at the time of the days 5, 10, 15, 20, 25 and 30 after the injury, and the final scores are showed in table 10.
[0000]
TABLE 10
Day 5
Day 10
Day 15
Day 20
Day 25
Day 30
total
mean
control
6
3
4
1
4
4
22
3.67 ± 1.63
group
silver
5
1
2
3
5
4
20
3.33 ± 1.63
sulfadiazine
1% cream
traditional
4
4
2
3
3
3
19
3.17 ± 0.75
Shiunko
ointment
SSN gel
6
2
4
4
6
5
27
4.5 ± 1.52
OSN gel
4
7
5
7
6
5
34
5.67 ± 1.21
MSN gel
8
6
5
7
7
6
39
6.5 ± 1.05
[0064] Please refer to table 10 and also FIGS. 5 (A)-(F), which are diagrams showing wound tissue sections in LM 20× after stained with Hematoxylin & Eosin at the time of 20 days after the burn injury and successive treatment of no drugs(a), silver sulfadiazine 1% cream(b), traditional Shiunko(c), SSN(d), OSN(e), and MSN(f) respectively according to the embodiment of the present invention. As the table 10 and the figures show, first, there are five dressings (control group, silver sulfadiazine 1% cream, traditional Shiunko ointment, SSN gel, MSN gel) having greater scores at the time of day 5 than those at the times of days 10, 15, 20, 25 and 30. Maybe it is because that the blood circulation of the wound tissues has not yet been cut off after burn injury, and hence the most wound tissues still have normal histomorphology. Second, based on the total scores, it is clear that the three different nanomicell gels have a better ability in wound repairing and healing than the control group, silver sulfadiazine 1% cream and traditional Shiunko. Further, the MSN gel has the best ability in wound repairing and healing than the OSN and the SSN gels, wherein the OSN gel is better than the SSN gel.
[0065] Based on the mention above, the SSN, the OSN and the MSN provided by the present invention, have a particle size below 100 nm even stored under the room temperature for 150 days, which shows the great stability. Further, the Shiunko nanomicell also shows the great ability in inhibition of Pseudomonas aeruginosa . As to the ability of wound repairing and healing, the Shiunko nanomicell obviously has the better ability than the traditional Shiunko prepared with wax and the silver sulfadiazine 1% cream. In addition, the Shiunko nanomicell is easy to be cleaned, and will not leave residues, which are all the benefits of the present invention.
[0066] From the evaluated results of the burn and scald model of rabbits, it shows that the OSN and the MSN gels have the better ability in wounds healing, however the OSN has a better ability in reducing scar. The evaluated results of wound tissue sections shows that the MSN has the greatest ability in healing than the OSN and SSN gels, and further the OSN is better than the SSN. However, no matter MSN, OSN, or SSN gel, is better than the control group, silver sulfadiazine 1% cream or traditional Shiunko. Accordingly, the Shiunko nanomicell gels provided by the present invention can be applied in burn and scald wounds to improve the healing and reduce the scar tissue, and further applied in relating skin diseases.
[0067] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.
REFERENCES
[0000]
1. Adam J. Singer, Henry C. Thode Jr., Steve A. McClain. Development of a histomorphologic scale to quantify cutaneous scars after burns. Acad Emerg Med. 2000, 7(10):1083-1088
|
The present invention provides a nanomicell for a skin, and the nanomicell includes an oil substance, an extract of a Angelica Radix, an extract of a Lithospermum Radix, and a phospholipid layer. The extract of a Angelica Radix is formed by extracting the Angelica Radix with the oil substance, and the extract of a Lithospermum Radix is formed by extracting the Lithospermum Radix with the oil substance. The extract of the Angelica Radix and the extract of the Lithospermum Radix are packaged within the phospholipid layer to form a plurality of micells having a diameter of nano-level.
| 0
|
This application claims priority from copending provisional application(s) Ser. No. 60/019,511 filed on Jun. 10, 1996.
BACKGROUND OF THE INVENTION
2,3-Pyridinedicarboximides are useful as intermediates in the preparation of herbicidal 2-(2-imidazolin-2-yl)nicotinic acids, esters and salts. Methods for the preparation of 2,3-pyridinedicarboximides are known in the art (see, e.g., U.S. Pat. No. 4,748,244; U.S. Pat. No. 4,754,033 and EP 308,084-Al). However, the methods described in those patents and patent application are not entirely satisfactory for the commercial manufacture of 2,3-pyridinedicarboximides.
It is, therefore, an object of the present invention to provide an effective and efficient process for the preparation of 2,3-pyridinedicarboximides.
It is also an object of the present invention to provide a compound which is useful in the process of this invention.
These and other objects and features of the present invention will become more apparent from the detailed description thereof set forth below.
SUMMARY OF THE INVENTION
The present invention provides an effective and efficient process for the preparation of a 2,3-pyridinedicarboximide having the structural formula I ##STR2## wherein R is hydrogen, C 1 -C 6 alkyl or C 1 -C 6 alkoxymethyl;
R 1 is hydrogen, C 1 -C 6 alkyl, C(O)R 2 ,
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups,
benzyl optionally substituted on the phenyl ring with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups, or ##STR3## R 2 is C 1 -C 6 alkyl, benzyl or phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups;
R 3 and R 4 are each independently C 1 -C 4 alkyl; and
R 5 is cyano or CONH 2 ,
which process comprises reacting an oxime or hydrazone having the structural formula II ##STR4## wherein R is as described above;
R 6 is C 1 -C 6 alkyl;
R 7 is OR 8 or NR 9 R 10 ;
R 8 is hydrogen, C 1 -C 6 alkyl, C(O)R 11 ,
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups, or
benzyl optionally substituted on the phenyl ring with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups;
R 11 is C 1 -C 6 alkyl, OR 12 , NR 12 R 13 , benzyl or
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups;
R 12 and R 13 are each independently hydrogen, C 1 -C 6 alkyl,
benzyl or
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups; and
R 9 and R 10 are each independently hydrogen, C 1 -C 6 alkyl,
benzyl or
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups,
with a maleimide having the structural formula III ##STR5## wherein R 1 is as described above.
This invention also relates to the formula II oximes described hereinabove.
DETAILED DESCRIPTION OF THE INVENTION
In one preferred embodiment of the present invention, an oxime or hydrazone represented by formula II is reacted with a maleimide represented by formula III, preferably in a temperature range of about 20° C. to 160° C., in the presence of a solvent.
Advantageously, it has now been found that 2,3-pyridinedicarboximides may be obtained in high yield and/or high purity by the effective and efficient process of the present invention.
The 2,3-pyridinedicarboximides may be isolated by diluting the reaction mixture with water and filtering the formula I product from the aqueous mixture. The product formula I compounds may also be isolated by concentrating the reaction mixture in vacuo and filtering the formula I product from the concentrated mixture. Alternatively, the reaction mixture may be integrated into the process used to prepare the final herbicidal agent without isolating the formula I compound.
Exemplary of halogen hereinabove are fluorine, chlorine, bromine and iodine.
In another embodiment of the present invention, a Lewis acid is present. Preferably, the Lewis acid is present in an amount up to about one molar equivalent relative to the formula II compound when R 8 is hydrogen. Lewis acids suitable for use in the present invention include any conventional Lewis acids. Preferred Lewis acids include aluminum chloride and titanium(IV) chloride.
Solvents suitable for use in the process of the present invention preferably have a boiling point of at least about 60° C. and include aromatic hydrocarbons such as toluene, xylenes, mesitylene and mixtures thereof; halogenated aromatic hydrocarbons such as mono--and dihalobenzenes and mixtures thereof; polynuclear aromatic hydrocarbons such as naphthalene, alkylnaphthalenes and mixtures thereof; ethers such as tetrahydrofuran and mixtures thereof; glycols such as 1,2-diethoxyethane and mixtures thereof; an alkanoic acid such as acetic acid, propionic acid and mixtures thereof; an alkanoic acid/water mixture such as an acetic acid/water mixture; acetonitrile; an acetonitrile/water mixture; and mixtures thereof. Preferred solvents include toluene, xylenes, mesitylene, acetonitrile, an acetonitrile/water mixture, acetic acid and mixtures thereof with toluene and acetonitrile being more preferred.
In another preferred embodiment of the present invention, oximes of formula II wherein R 7 is OR 8 are reacted with maleimides of formula III preferably at a temperature range of about 60° C. to 160° C., more preferably about 75° C. to 135° C. And hydrazones of formula II wherein R 7 is NR 9 R 10 are reacted with maleimides of formula III preferably at a temperature range of about 20° C. to 160° C., more preferably about 20° C. to 135° C.
In a further preferred embodiment of the present invention, a base is present when R is C 1 -C6alkoxymethyl. The base is used to reduce the amount of 5-methyl-2,3-pyridinedicarboximides which are produced as undesirable by-products when R is C 1 -C 6 alkoxymethyl.
Bases suitable for use in the present invention include, but are not limited to, tri(C 2 -C 4 alkyl)amines such as triethylamine, N,N-diethylisopropylamine, N,N-diisopropylethylamine and the like, alkali metal acetates such as sodium acetate, potassium acetate and the like, and mixtures thereof. Preferred bases include triethylamine, sodium acetate and potassium acetate. The base is preferably present in an amount of at least about one molar equivalent relative to the formula II compound.
In a further embodiment of the present invention, a phase transfer catalyst is present when the base is present. Preferably, the phase transfer catalyst is present when the alkali metal acetate is present. Phase transfer catalysts suitable for use in the present invention include any conventional phase transfer catalysts. Preferred phase transfer catalysts include crown ethers such as 18-crown-6 and 15-crown-5.
In a preferred process of the present invention,
R is hydrogen, C 1 -C 4 alkyl or C 1 -C 4 alkoxymethyl;
R 1 is hydrogen, C 1 -C 4 alkyl,
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups, or ##STR6## R 3 and R 4 are each independently C 1 -C 4 alkyl; R 5 is cyano or CONH 2 ;
R 6 is C 1 -C 4 alkyl;
R 7 is OR 8 ; and
R 8 is hydrogen or C 1 -C 6 alkyl.
In a more preferred process of the present invention,
R is hydrogen, methyl, ethyl or methoxymethyl;
R 1 is methyl, phenyl or ##STR7## R 5 is cyano or CONH 2 ; R 6 is methyl or ethyl;
R 7 is OR 8 ; and
R 8 is hydrogen or methyl.
Formula II oximes wherein
R 7 is OR 8 ; and
R 8 is hydrogen, C 1 -C 6 alkyl,
phenyl optionally substituted with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups, or
benzyl optionally substituted on the phenyl ring with any combination of from one to four halogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, nitro or cyano groups,
may be prepared by reacting a 3-alkoxy-2-propenal of formula IV with a substituted hydroxylamine of formula V optionally in the presence of a base. The reaction scheme is shown below in Flow Diagram I. ##STR8##
Alternatively, oximes of formula II wherein R 8 is C 1 -C 6 alkyl may be prepared by reacting a formula II compound wherein R 8 is hydrogen with a dialkyl sulfate of formula VI in the presence of a base such as sodium hydroxide or an alkali metal alkoxide. The reaction scheme is shown in Flow Diagram II. ##STR9##
Formula II oximes wherein R 8 is C(O)R 11 may be prepared by reacting a formula II compound wherein R 8 is hydrogen with an acid chloride of formula VII or an anhydride of formula VIII as shown in Flow Diagram III. ##STR10##
Formula II hydrazones may be prepared by reacting a 3-alkoxy-2-propenal of formula IV with a hydrazine of formula IX optionally in the presence of an acid catalyst such as acetic acid. The reaction scheme is shown in Flow Diagram IV. ##STR11##
3-Alkoxy-2-propenal compounds of formula IV may be prepared according to the procedures described by E. Breitmaier, et al in Synthesis, pages 1-9 (1987). Maleimide compounds of formula III are known in the art and may be prepared according to the procedures described by M. Cava, et al in Organic Synthesis, 41, page 93 (1961).
Alternatively, formula IV compounds wherein R is methoxymethyl may be prepared by reacting a 3-(dialkyl-amino)-2-propenal of formula X with formaldehyde and methanol in the presence of a mineral acid such as sulfuric acid to form a 3-(dialkylamino)-2-(methoxy-methyl)-2-propenal of formula XI, and reacting the formula XI compound with a base such as an alkali metal hydroxide and a dialkyl sulfate of formula VI. The reaction scheme is shown in Flow Diagram V. ##STR12##
The present invention also provides a process for the preparation of a herbicidal 5-(alkoxymethyl)-2-(2-imidazolin-2-yl)-nicotinic acid, ester and salt compound having the formula ##STR13## wherein R is as defined above;
R 14 is C 1 -C 4 alkyl;
R 15 is C 1 -C 4 alkyl, C 3 -C 6 cycloalkyl or R 14 and R 15 when taken together with the atom to which they are attached, represent a C 3 -C 6 cycloalkyl group optionally substituted with methyl and
R 16 is hydrogen, diloweralkylimino,
C 1 -C 12 alkyl optionally substituted with one of the following groups: C 1 -C 3 alkoxy, halogen, hydroxy, C 3 -C 6 cycloalkyl, benzyloxy, furyl, phenyl, halophenyl, lower alkylphenyl, lower alkoxyphenyl, nitrophenyl, carboxyl, loweralkoxycarbonyl, cyano or triloweralkylammonium;
C 3 -C 12 alkenyl optionally substituted with one of the following groups: C 1 -C 3 alkoxy, phenyl, halogen or loweralkoxycarbonyl or with two C 1 -C 3 alkoxy groups or two halogen groups;
C 3 -C 6 cycloalkyl optionally substituted with one or two C 1 -C 3 alkyl groups; or
a cation preferably selected from the group consisting of alkali metals, alkaline earth metals, manganese, copper, iron, zinc, cobalt, lead, silver, nickel, ammonium and organic ammonium;
which process comprises:
(a) preparing a compound having the formula I ##STR14## wherein R and R 1 are as defined above by a process as defined above; and
(b) converting the compound having formula I into the compound having the formula XII.
The term "lower" as used above in relation to alkyl and alkoxy groups means that the alkyl or alkoxy group contains 1 to 6, preferably 1 to 4, carbon atoms.
The conversion of the compound having formula I into the compound having formula XII may be carried out in a variety of ways. One may plan routes by combining reactions known for the conversion of one carboxylic acid derivative into another.
Methods that may be used to create the imidazolinone herbicides are illustrated in the book "The Imidazolinone Herbicides" edited by D. L. Shaner and S. L. O'Connor, published 1991 by CRC Press, Boca Raton, Fla. with particular reference to Chapter 2 entitled "Synthesis of the Imidazolinone Herbicides", pages 8-14 and the references cited therein. The following patent literature references also illustrate the methods that may be used to convert the carboxylic acid derivatives into imidazolinone final products:
U.S. Pat. Nos. 5,371,229; 5,334,576; 5,250,694; 5,276,157; 5,110,930; 5,122,608; 5,206,368; 4,925,944; 4,921,961; 4,959,476; 5,103,009; 4,816,588; 4,748,244; 4,754,033; 4,757,146; 4,798,619; 4,766,218; 5,001,254; 5,021,078; 4,723,011; 4,709,036; 4,658,030; 4,608,079; 4,719,303; 4,562,257; 4,518,780; 4,474,962; 4,623,726; 4,750,978; 4,638,068; 4,439,607; 4,459,408; 4,459,409; 4,460,776; 4,125,727 and 4,758,667, and European Patent Application Nos. EP-A-0-041,623 and EP-A-0-308,084.
In order to facilitate a further understanding of the invention, the following examples are presented primarily for the purpose of illustrating more specific details thereof. The invention should not be deemed limited by the examples as the full scope of the invention is defined in the claims.
EXAMPLE 1
Preparation of the Oxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- ##STR15##
3-Ethoxy-2-methyl-2-propenal, (E)-- and (Z)-- (30.0 g, 0.25 mol) is added dropwise to a mixture of hydroxylamine sulfate (33.0 g, 0.2 mol) and sodium acetate (33.4 g, 0.4 mol) in water (200 g). The resultant reaction mixture is stirred overnight and filtered to obtain a solid. The solid is washed with water and dried to give the title product as a white solid (23.2 g, mp 78° C., 71% yield).
Using essentially the same procedure, but substituting methoxylamine hydrochloride for hydroxylamine sulfate, the O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- is obtained as a yellow oil.
EXAMPLE 2
Preparation of the O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- ##STR16##
A mixture of the oxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- (0.5 g, 3.87 mmol) and potassium tert-butoxide (0.48 g, 4.2 mmol) in tetrahydrofuran is stirred for ten minutes at 10° C., treated dropwise with dimethyl sulfate (0.59 g, 4.6 mmol), stirred for two hours and filtered. The resultant filtrate is concentrated in vacuo to give the title product as a yellow oil (0.74 g, 100% yield).
EXAMPLE 3
Preparation of 5-Methyl-N-phenyl-2,3-pyridinedicarboximide ##STR17##
A solution of N-phenylmaleimide (1.69 g, 9.8 mmol) in toluene (16 g) is refluxed for 24 hours. During the reflux period, the O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- (1.57 g, 11 mmol) is added portionwise to the reaction mixture. The final reaction mixture is then concentrated in vacuo to give the title product as a orange solid (1.2 g, 52% yield).
EXAMPLES 4-7
Using essentially the same procedure as described in Example 3, but substituting the oxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)-- for the O-methyloxime of 3-ethoxy-2-methyl-2-propen-1-one, (E)-- and (Z)--, 5-methyl-N-phenyl-2,3-pyridinedicarboximide is produced in the yields shown in Table I.
TABLE I______________________________________Preparation of 5-Methyl-N-phenyl-2,3-pyridinedicarboximide EquivalentsExam- of N-phenyl- Lewis Acid/ Hours %ple maleimide Equivalents Solvent Refluxed Yield______________________________________4 0.3 AlCl.sub.3 /0.2 Toluene 27 205 0.3 TiCl.sub.4 /0.3 Toluene 10 106 0.2 -- H.sub.2 O/CH.sub.3 CN 12 15 (1:1)7 2.0 -- CH.sub.3 CO.sub.2 H 9 15______________________________________
EXAMPLE 8
Preparation of 3-(Dimethylamino)-2-(methoxymethyl)-2-propenal, (E)-- and (Z)-- ##STR18##
Concentrated sulfuric acid (1 mL) is slowly added to a solution of 3-(dimethylamino)-2-propenal (200 g, 2.01 mol) and paraformaldehyde (90 g, 3 mol) in methanol (1 L). The resultant solution is refluxed overnight, concentrated in vacuo to a volume of 200 mL, diluted with toluene and distilled until the vapor temperature is 105° C. The solution is then concentrated in vacuo to give the title product as an orange oil (251.4 g, 87% yield).
EXAMPLE 9
Preparation of 3-Methoxy-2-(methoxymethyl)-2-propenal, (E)-- and (Z)-- ##STR19##
A solution of 3-(dimethylamino)-2-(methoxymethyl)-2-propenal, (E)-- and (Z)-- (53.06 g, 0.37 mol) and sodium hydroxide solution (29.7 g, 50%, 0.37 mol) in methanol (60 mL) is refluxed for 20 minutes and concentrated in vacuo to obtain a white solid. A solution of the solid in water (250 mL) is treated dropwise with dimethyl sulfate (46.75 g, 0.37 mol), stirred at room temperature for one hour and extracted with methylene chloride. The organic extract is dried over anhydrous sodium sulfate, concentrated in vacuo and distilled to give the title product as a colorless liquid (19.66 g, bp 80° C./0.5 mm Hg, 41% yield).
EXAMPLE 10
Preparation of 5-(Methoxymethyl)-N-phenyl-2,3-pyridinedicarboximide ##STR20##
A solution of methoxyamine hydrochloride (1.7 g, 20 mmol) and sodium acetate (2.1 g, 25.6 mmol) in water (30 mL) is treated dropwise with 3-methoxy-2-(methoxymethyl)-2-propenal, (E)-- and (Z)-- (2.2 g, 16.9 mmol), stirred at room temperature for 30 minutes and extracted with methylene chloride. The organic extract is dried over anhydrous sodium sulfate and concentrated in vacuo to obtain the O-methyloxime of 3-methoxy-2-(methoxymethyl)-2-propen-1-one. A mixture of the resultant O-methyloxime of 3-methoxy-2-(methoxymethyl)-2-propen-1-one, N-phenylmaleimide (2.9 g, 16.8 mmol) and diisopropylethylamine (2.2 g, 17.0 mmol) in toluene (50 mL) is refluxed for 23 hours. During the reflux period, additional N-phenylmaleimide (2.9 g, 16.8 mmol) is added to the reaction mixture. The final reaction mixture is concentrated in vacuo to give the title product as a solid (0.36 g, 8% yield) having a 5-(methoxymethyl)-N-phenyl-2,3-pyridinedicarboximide to 5-methyl-N-phenyl-2,3-pyridinedicarboximide ratio of 50:1.
EXAMPLE 11
Preparation of 3-Ethoxy-2-methylacrolein dimethylhydrazone, (E)-- and (Z)-- ##STR21##
A mixture of 3-ethoxy-2-methyl-2-propenal, (E)-- and (Z)-- (4.0 g, 35 mmol), 1,1-dimethylhydrazine (2.73 g, 46 mmol) and acetic acid (0.04 g, 0.7 mmol) in diethyl ether is refluxed for one hour, cooled, washed sequentially with water and brine, dried over anhydrous magnesium sulfate, and concentrated in vacuo to give the title product as a yellow oil.
EXAMPLE 12
Preparation of 5-Methyl-N-phenyl-2,3-pyridinedicarboximide from N-phenylmaleimide and 3-ethoxy-2-methylacrolein dimethylhydrazone, (E)-- and (Z)-- ##STR22##
A solution of N-phenylmaleimide (1.1 g, 6.4 mmol) in acetonitrile is refluxed for 19 hours. During the reflux period, 3-ethoxy-2-methylacrolein dimethylhydrazone, (E)-- and (Z)-- (1.2 g, 7.6 mmol) is added portionwise to the reaction mixture. The final reaction mixture is then concentrated in vacuo to give the title product as a dark oil (0.23 g, 15% yield).
|
There is provided a process for the preparation of 2,3-pyridinedicarboximides having the structural formula I ##STR1## The 2,3-pyridinedicarboximides are useful as intermediates in the preparation of herbicidal 2-(2-imidazolin-2-yl)nicotinic acids, esters and salts.
| 2
|
CROSS REFERENCED TO RELATED APPLICATIONS
[0001] This application is a Continuation in Part of U.S. application Ser. No. 10/912,284; filed Aug. 8, 2004, which is a Continuation-in-Part of U.S. Application Serial No. 10/252,139; filed Sep. 20, 2002, which claims benefit of Provisional patent application Ser. No. 60/323,729, filed Sep. 20, 2001.
BACKGROUND OF THE INVENTION
[0002] Electrically tunable filters have many uses in microwave and radio frequency systems. Compared to mechanically and magnetically tunable filters, electronically tunable filters have the important advantage of fast tuning capability over wide band application. Because of this advantage, they can be used in the applications such as, by way of example and not by way of limitation, LMDS (local multipoint distribution service), PCS (personal communication system), frequency hopping, satellite communication, and radar systems.
[0003] Filters for use in radio link communications systems have been required to provide better performance with smaller size and lower cost. Significant efforts have been made to develop new types of resonators, new coupling structures and new configurations for the filters. In some applications where the same radio is used to provide different capacities in terms of Mbits/sec, the intermediate frequency (IF) filter's bandwidth has to change accordingly. In other words, to optimize the performance of radio link for low capacity radios, a narrow band IF filter is used while for higher capacities wider band IF filters are needed. This requires using different radios for different capacities, because they have to use different IF filters. However, if the bandwidth of the IF filter could be varied electronically, the same configuration of radio could be used for different capacities which will help to simplify the architecture of the radio significantly, as well as reduce cost.
[0004] Traditional electronically tunable filters use semiconductor diode varactors to change the coupling factor between resonators. Since a diode varactor is basically a semiconductor diode, diode varactor-tuned filters can be used in various devices such as monolithic microwave integrated circuits (MMIC), microwave integrated circuits or other devices. The performance of varactors is defined by the capacitance ratio, Cmax/Cmin, frequency range, and figure of merit, or Q factor at the specified frequency range. The Q factors for semiconductor varactors for frequencies up to 2 GHz are usually very good. However, at frequencies above 2 GHz, the Q factors of these varactors degrade rapidly.
[0005] Since the Q factor of semiconductor diode varactors is low at high frequencies (for example, <20 at 20 GHz), the insertion loss of diode varactor-tuned filters is very high, especially at high frequencies (>5 GHz). Another problem associated with diode varactor-tuned filters is their low power handling capability. Further, since diode varactors are nonlinear devices, their handling of signals may generate harmonics and subharmonics.
[0006] Commonly owned U.S. patent application Ser. No. 09/419,219, filed Oct. 15, 1999, and titled “Voltage Tunable Varactors And Tunable Devices Including Such Varactors”, discloses voltage tunable dielectric varactors that operate at room temperature and various devices that include such varactors, and is hereby incorporated by reference. Compared with the traditional semiconductor diode varactors, dielectric varactors have the merits of lower loss, higher power-handling, higher IP3, and faster tuning speed.
[0007] High power amplifiers are also an important part of any radio link. They are required to output maximum possible power with minimum distortion. One way to achieve this is to use feed forward amplifier technology. A typical feed forward amplifier includes two amplifiers (the main and error amplifiers), directional couplers, delay lines, gain and phase adjustment devices, and loop control networks. The main amplifier generates a high power output signal with some distortion while the error amplifier produces a low power distortion-cancellation signal.
[0008] In a typical feed forward amplifier, a radio frequency (RF) signal is input into a power splitter. One part of the RF signal goes to the main amplifier via a gain and phase adjustment device. The output of the main amplifier is a higher level, distorted carrier signal. A portion of this amplified and distorted carrier signal is extracted using a directional coupler, and after going through an attenuator, reaches a carrier cancellation device at a level comparable to the other part of the signal that reaches carrier cancellation device after passing through a delay line. The delay line is used to match the timing of both paths before the carrier cancellation device. The output of carrier cancellation device is a low level error or distortion signal. This signal, after passing through another gain and phase adjustment device, gets amplified by the low power amplifier. This signal is then subtracted from the main distorted signal with an appropriate delay to give the desired non-distorted output carrier.
[0009] Traditionally, delay lines have been used to give the desired delay and provide the above-described functionality. However, delay filters have become increasingly popular for this application because they are smaller, easily integrated with other components, and have lower insertion loss, as compared to their delay line counterpart. A fixed delay filter can be set to give the best performance over the useable bandwidth. This makes the operation of a feed forward amplifier much easier, as compared to the tuning of a delay line, which simulates adjustment of the physical length of a cable. However, fixed delay filters still have to be tuned manually.
[0010] The use of Feedforward techniques to reduce intermodulation distortion, caused by the power amplifier in the Tx path is well known. However, there is a strong need for reducing the noise signal in the Rx band thereby relaxing the rejection requirement of the Tx filter in a Duplexer and decreasing the insertion loss,
SUMMARY OF THE INVENTION
[0011] An embodiment of the present invention provides an apparatus, comprising a transceiver with a feed forward amplifier including a plurality of cancellation loops, wherein at least one of the plurality of cancellation loops includes a tunable filter enabling the noise signal in a Rx band to be reduced. Further, at least one of the plurality of cancellation loops may include a tunable filter which provides the capability to reduce intermodulation signals and the tunable filter may include a voltage tunable dielectric material to enable the tuning.
[0012] The cancellation loop which includes a tunable delay enabling the noise signal in a Rx band to be reduced may further include a Rx filter preceding the tunable delay and a power amplifier after the tunable delay thereby enabling a signal capable of canceling any noise signals input into the apparatus. The cancellation of any noise signal input into the apparatus may be accomplished by the signal generated in the cancellation loop being approximately 180 degrees out of phase and of equal amplitude to the input signal and being added to the input signal. The generation of the signal being approximately 180 degrees out of phase with the input signal may be accomplished by applying the voltage tunable delay within the cancellation loop to the signal to which is to be combined with the input signal.
[0013] An embodiment of the present invention further provides an apparatus capable of reducing selected signal components in a communication link comprising a signal line conveying a communication signal including a desired signal component and at least one undesired signal component; a first signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a first of the at least one undesired signal components; and a second signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a second of the at least one undesired signal components. The first signal loop may include a tunable delay enabling the generation of the signal that when combined with the first signal line reduces a first of the at least one undesired signal components. Further, the second signal loop may include a tunable delay enabling the generation of the signal that when combined with the first signal line reduces a second of the at least one undesired signal components. The first of the at least one undesired signal components may be intermodulation distortion and the adding of a signal generated by the first signal loop may reduce or eliminate it. Further, a second of the at least one undesired signal components may be receive signal distortion and the adding of a signal generated by the second signal loop may reduce or eliminate it.
[0014] The tunable delay may be tuned by using a voltage tunable dielectric material and the signal line may be coupled with a first signal source. The desired signal component may be a transmission signal and the at least one undesired signal component may be a received signal and an intermodulation distortion generated by signal line components operating on the communication signal.
[0015] Yet another embodiment of the present invention provides a method of reducing selected signal components in a communication link comprising conveying a communication signal including a desired signal component and at least one undesired signal component; combining a signal generated by a first signal loop with the communication signal such that when combined a reduction or elimination of a first of the at least one undesired signal components occurs; and combining a signal generated by a second signal loop with the communication signal such that when combined a reduction or elimination of a second of the at least one undesired signal components occurs.
[0016] The present method may further comprise applying a tunable delay within the first signal loop thereby enabling the generation of a signal that when combined with the communication signal reduces a first of the at least one undesired signal components or may further comprise applying a tunable delay within the second signal loop thereby enabling the generation of a signal that when combined with the communication signal reduces a second of the at least one undesired signal components. The tunable delay may be tuned by using a voltage tunable dielectric material such as, but not limited to, Parascan® dielectric material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
[0018] FIG. 1 provides a feed forward power amplifier diagram capable of reducing intermodulation distortion and Rx noise;
[0019] FIG. 2 illustrates the signal spectrum at the input with Tx signal and Rx noise of one embodiment of the present invention;
[0020] FIG. 3 illustrates the signal spectrum at point a of FIG. 1 with Tx signal and Rx noise and Intermodulation signals;
[0021] FIG. 4 illustrates the signal spectrum at point b of FIG. 1 with Intermodulation signals;
[0022] FIG. 5 illustrates the signal spectrum at point c of FIG. 1 with the Tx signal and Rx noise amplified; and
[0023] FIG. 6 illustrates the signal spectrum at point d of FIG. 1 with the Rx noise.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.
[0025] Intermodulation distortion caused by a power amplifier in a Tx path is problematic and Feedforward techniques to reduce or overcome this have been developed. The parent application to the present application discloses a tunable delay line used in the feed forward cancellation loop, based on BST tunable dielectric material and provides significant reduction of intermodulation signals. This application is set forth in the Cross Reference Section and is incorporated into the present application by reference. The present invention provides further improvement by adding at least one additional loop which enables the noise signal in the Rx band to be reduced, which helps relax the rejection requirement of the Tx filter in the Duplexer and decreases the insertion loss, thereby increasing the output power. Thus, an embodiment of the present invention provides a feed forward amplifier with a plurality of cancellation loops (such as, but not limited to, two cancellation loops) to reduce intermodulation distortion and Rx band noise when amplifying the Tx band signal.
[0026] Rx band noise signals may also be amplified and transferred to the duplexer. These signals enter the receiver without attenuation and will decrease signal to noise ratio (SNR) of the receiver. This could be avoided by increasing the isolation between Tx and Rx in the Duplexer, but it would require front end filters with more rejection, with associated higher insertion loss. In an embodiment of the present invention, in an alternative approach is used a second loop in feedforward amplifier to reduce this noise as shown generally as 100 of FIG. 1 ; which depicts a feed forward power amplifier diagram capable of reducing intermodulation distortion and Rx noise with input 118 with Tx signal 104 and Rx noise 102 of one embodiment of the present invention. The input signal 118 in the transmit path contains Tx signal 104 , and some noise 102 in the Rx band: f 1 and f 2 ( 102 ) are two tones of noise in Rx band and f 3 and f 4 ( 104 ) are two tones in Tx band.
[0027] This signal, after some amplitude 122 and phase 120 adjustment, will reach the main power amplifier, PA 106 . The PA 106 will amplify the Tx signal 104 , the Rx noise 102 , and will generate some intermodulation signals as shown by 108 and 110 with Tx signal with intermodulation 110 and Rx noise 108 .
[0028] A portion of signal a 126 is coupled off and then divided in two halves by a divider 124 (such as, but not limited to, a Wilkinson divider). One half will go to the combiner 150 after some amplitude adjustments 136 . At the input 118 , a portion of the input signal will be coupled off and after passing through the tunable delay line 148 will be subtracted from the signal coming from point a 126 . The signal f 1 and f 2 are depicted as 144 and f 3 and f 4 at 146 . The output of the combiner 150 will therefore contain only the intermodulation signal 138 . This is achieved when the two signals reaching the combiner 150 have exactly the same amplitude, and are out of phase. The presence of tunable delay line 148 may enable this wide band cancellation. This signal, after some amplitude 151 and phase 152 adjustments will be amplified by an error amplifier, Amp 154 , and is shown at point b 130 .
[0029] The signal at point b 130 will then be coupled, or subtracted from signal a 126 to give signal c 132 without intermodulation distortion, as shown at 116 . The cancellation is achieved, when the amplitude of this signal is exactly equal to the amplitude of intermodulation signal at point a 126 with 180 phase shift.
[0030] It is observed that the noise in the receive band, f 1 and f 2 ( 112 ), are still present at point c 132 with Tx signal depicted as 114 . The purpose of the second loop is to eliminate this noise, as described follows: The other half of signal a 126 from Divider 124 will go through a bandpass filter 158 at the frequency of Rx. This filter 158 will reject Tx signals and intermodulation signals. Alternatively, a notch filter could be used to reject the Tx spectrum. This signal, after going through a tunable delay line 160 , phase shifter P 162 , and attenuator A 164 , will be amplified using an error amplifier Amp 156 . Parascan® material may be used in either or both the tunable delays for achieving wide band cancellation and to compensate for any temperature drift in other components of the loop.
[0031] The term Parascan® as used herein is a trademarked term indicating a tunable dielectric material developed by the assignee of the present invention. Parascan® tunable dielectric materials have been described in several patents. Barium strontium titanate (BaTiO3—SrTiO3), also referred to as BSTO, is used for its high dielectric constant (200-6,000) and large change in dielectric constant with applied voltage (25-75 percent with a field of 2 Volts/micron). Tunable dielectric materials including barium strontium titanate are disclosed in U.S. Pat. No. 5,312,790 to Sengupta, et al. entitled “Ceramic Ferroelectric Material”; U.S. Pat. No. 5,427,988 by Sengupta, et al. entitled “Ceramic Ferroelectric Composite Material-BSTO-MgO”; U.S. Pat. No. 5,486,491 to Sengupta, et al. entitled “Ceramic Ferroelectric Composite Material—BSTO-ZrO2”; U.S. Pat. No. 5,635,434 by Sengupta, et al. entitled “Ceramic Ferroelectric Composite Material-BSTO-Magnesium Based Compound”; U.S. Pat. No. 5,830,591 by Sengupta, et al. entitled “Multilayered Ferroelectric Composite Waveguides”; U.S. Pat. No. 5,846,893 by Sengupta, et al. entitled “Thin Film Ferroelectric Composites and Method of Making”; U.S. Pat. No. 5,766,697 by Sengupta, et al. entitled “Method of Making Thin Film Composites”; U.S. Pat. No. 5,693,429 by Sengupta, et al. entitled “Electronically Graded Multilayer Ferroelectric Composites”; U.S. Pat. No. 5,635,433 by Sengupta entitled “Ceramic Ferroelectric Composite Material BSTO-ZnO”; U.S. Pat. No. 6,074,971 by Chiu et al. entitled “Ceramic Ferroelectric Composite Materials with Enhanced Electronic Properties BSTO Mg Based Compound-Rare Earth Oxide”. These patents are incorporated herein by reference. The materials shown in these patents, especially BSTO-MgO composites, show low dielectric loss and high tunability. Tunability is defined as the fractional change in the dielectric constant with applied voltage.
[0032] Barium strontium titanate of the formula BaxSr1—xTiO3 is a preferred electronically tunable dielectric material due to its favorable tuning characteristics, low Curie temperatures and low microwave loss properties. In the formula BaxSr1—xTiO3, x can be any value from 0 to 1, preferably from about 0.15 to about 0.6. More preferably, x is from 0.3 to 0.6.
[0033] Other electronically tunable dielectric materials may be used partially or entirely in place of barium strontium titanate. An example is BaxCa1—xTiO3, where x is in a range from about 0.2 to about 0.8, preferably from about 0.4 to about 0.6. Additional electronically tunable ferroelectrics include PbxZr1—xTiO3 (PZT) where x ranges from about 0.0 to about 1.0, PbxZr1—xSrTiO3 where x ranges from about 0.05 to about 0.4, KTaxNb1—xO3 where x ranges from about 0.0 to about 1.0, lead lanthanum zirconium titanate (PLZT), PbTiO3, BaCaZrTiO3, NaNO3, KNbO3, LiNbO3, LiTaO3, PbNb2O6, PbTa2O6, KSr(NbO3) and NaBa2(NbO3)5 KH2PO4, and mixtures and compositions thereof. Also, these materials can be combined with low loss dielectric materials, such as magnesium oxide (MgO), aluminum oxide (Al2O3), and zirconium oxide (ZrO2), and/or with additional doping elements, such as manganese (MN), iron (Fe), and tungsten (W), or with other alkali earth metal oxides (i.e. calcium oxide, etc.), transition metal oxides, silicates, niobates, tantalates, aluminates, zirconnates, and titanates to further reduce the dielectric loss.
[0034] In addition, the following U.S. Patent Applications, assigned to the assignee of this application, disclose additional examples of tunable dielectric materials: U.S. application Ser. No. 09/594,837 filed Jun. 15, 2000, entitled “Electronically Tunable Ceramic Materials Including Tunable Dielectric and Metal Silicate Phases”; U.S. application Ser. No. 09/768,690 filed Jan. 24, 2001, entitled “Electronically Tunable, Low-Loss Ceramic Materials Including a Tunable Dielectric Phase and Multiple Metal Oxide Phases”; U.S. application Ser. No. 09/882,605 filed Jun. 15, 2001, entitled “Electronically Tunable Dielectric Composite Thick Films And Methods Of Making Same”; U.S. application Ser. No. 09/834,327 filed Apr. 13, 2001, entitled “Strain-Relieved Tunable Dielectric Thin Films”; and U.S. Provisional Application Ser. No. 60/295,046 filed Jun. 1, 2001 entitled “Tunable Dielectric Compositions Including Low Loss Glass Frits”. These patent applications are incorporated herein by reference.
[0035] The tunable dielectric materials can also be combined with one or more non-tunable dielectric materials. The non-tunable phase(s) may include MgO, MgAl2O4, MgTiO3, Mg2SiO4, CaSiO3, MgSrZrTiO6, CaTiO3, Al2O3, SiO2 and/or other metal silicates such as BaSiO3 and SrSiO3. The non-tunable dielectric phases may be any combination of the above, e.g., MgO combined with MgTiO3, MgO combined with MgSrZrTiO6, MgO combined with Mg2SiO4, MgO combined with Mg2SiO4, Mg2SiO4 combined with CaTiO3 and the like.
[0036] Additional minor additives in amounts of from about 0.1 to about 5 weight percent can be added to the composites to additionally improve the electronic properties of the films. These minor additives include oxides such as zirconnates, tannates, rare earths, niobates and tantalates. For example, the minor additives may include CaZrO3, BaZrO3, SrZrO3, BaSnO3, CaSnO3, MgSnO3, Bi2O3/2SnO2, Nd2O3, Pr7O11, Yb2O3, Ho2O3, La2O3, MgNb2O6, SrNb2O6, BaNb2O6, MgTa2O6, BaTa2O6 and Ta2O3.
[0037] Thick films of tunable dielectric composites may comprise Ba1—xSrxTiO3, where x is from 0.3 to 0.7 in combination with at least one non-tunable dielectric phase selected from MgO, MgTiO3, MgZrO3, MgSrZrTiO6, Mg2SiO4, CaSiO3, MgAl2O4, CaTiO3, Al2O3, SiO2, BaSiO3 and SrSiO3. These compositions can be BSTO and one of these components, or two or more of these components in quantities from 0.25 weight percent to 80 weight percent with BSTO weight ratios of 99.75 weight percent to 20 weight percent.
[0038] The electronically tunable materials may also include at least one metal silicate phase. The metal silicates may include metals from Group 2A of the Periodic Table, i.e., Be, Mg, Ca, Sr, Ba and Ra, preferably Mg, Ca, Sr and Ba. Preferred metal silicates include Mg2SiO4, CaSiO3, BaSiO3 and SrSiO3. In addition to Group 2A metals, the present metal silicates may include metals from Group 1A, i.e., Li, Na, K, Rb, Cs and Fr, preferably Li, Na and K. For example, such metal silicates may include sodium silicates such as Na2SiO3 and NaSiO3—5H2O, and lithium-containing silicates such as LiAlSiO4, Li2SiO3 and Li4SiO4. Metals from Groups 3A, 4A and some transition metals of the Periodic Table may also be suitable constituents of the metal silicate phase. Additional metal silicates may include Al2Si2O7, ZrSiO4, Ka1Si3O8, NaAlSi3O8, CaAl2Si2O8, CaMgSi2O6, BaTiSi3O9 and Zn2SiO4. The above tunable materials can be tuned at room temperature by controlling an electric field that is applied across the materials.
[0039] In addition to the electronically tunable dielectric phase, the electronically tunable materials can include at least two additional metal oxide phases. The additional metal oxides may include metals from Group 2A of the Periodic Table, i.e., Mg, Ca, Sr, Ba, Be and Ra, preferably Mg, Ca, Sr and Ba. The additional metal oxides may also include metals from Group 1A, i.e., Li, Na, K, Rb, Cs and Fr, preferably Li, Na and K. Metals from other Groups of the Periodic Table may also be suitable constituents of the metal oxide phases. For example, refractory metals such as Ti, V, Cr, Mn, Zr, Nb, Mo, Hf, Ta and W may be used. Furthermore, metals such as Al, Si, Sn, Pb and Bi may be used. In addition, the metal oxide phases may comprise rare earth metals such as Sc, Y, La, Ce, Pr, Nd and the like.
[0040] The additional metal oxides may include, for example, zirconnates, silicates, titanates, aluminates, stannates, niobates, tantalates and rare earth oxides. Preferred additional metal oxides include Mg2SiO4, MgO, CaTiO3, MgZrSrTiO6, MgTiO3, MgAl2O4, WO3, SnTiO4, ZrTiO4, CaSiO3, CaSnO3, CaWO4, CaZrO3, MgTa2O6, MgZrO3, MnO2, PbO, Bi2O3 and La2O3. Particularly preferred additional metal oxides include Mg2SiO4, MgO, CaTiO3, MgZrSrTiO6, MgTiO3, MgAl2O4, MgTa2O6 and MgZrO3.
[0041] The additional metal oxide phases are typically present in total amounts of from about 1 to about 80 weight percent of the material, preferably from about 3 to about 65 weight percent, and more preferably from about 5 to about 60 weight percent. In one preferred embodiment, the additional metal oxides comprise from about 10 to about 50 total weight percent of the material. The individual amount of each additional metal oxide may be adjusted to provide the desired properties. Where two additional metal oxides are used, their weight ratios may vary, for example, from about 1:100 to about 100:1, typically from about 1:10 to about 10:1 or from about 1:5 to about 5:1. Although metal oxides in total amounts of from 1 to 80 weight percent are typically used, smaller additive amounts of from 0.01 to 1 weight percent may be used for some applications.
[0042] The additional metal oxide phases can include at least two Mg-containing compounds. In addition to the multiple Mg-containing compounds, the material may optionally include Mg-free compounds, for example, oxides of metals selected from Si, Ca, Zr, Ti, Al and/or rare earths.
[0043] The signal at point d 142 only contains the Rx noise signal f 1 and f 2 140 . Similar to the first cancellation loop, the signal at point d 142 will be subtracted from the signal at pint c 132 resulting in the output transmit signal 134 containing only the Tx tones f 3 and f 4 116 .
[0044] FIGS. 2-6 further illustrate the signals at various stages of the diagram of FIG. 1 . Turning to FIG. 2 , illustrated generally at 200 is shown the signal spectrum at the input with Tx signal 210 and Rx noise 205 of one embodiment of the present invention. FIG. 3 , generally at 300 , illustrates the signal spectrum at point a 126 of FIG. 1 with Tx signal 310 and 312 and Rx noise 305 and Intermodulation signals 315 and 320 of one embodiment of the present invention;
[0045] FIG. 4 illustrates generally at 400 , the signal spectrum at point b 130 of FIG. 1 with Intermodulation signals 405 . FIG. 5 illustrates generally at 500 the signal spectrum at point c 132 of FIG. 1 with the Tx signal 510 and Rx noise 505 amplified. FIG. 6 illustrates generally at 600 the signal spectrum at point d 142 of FIG. 1 with the Rx noise 605 .
[0046] While the present invention has been described in terms of what are at present believed to be its preferred embodiments, those skilled in the art will recognize that various modifications to the disclose embodiments can be made without departing from the scope of the invention as defined by the following claims.
|
An embodiment of the present invention further provides an apparatus capable of reducing selected signal components in a communication link comprising a signal line conveying a communication signal including a desired signal component and at least one undesired signal component; a first signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a first of the at least one undesired signal components; and a second signal loop coupled to the first signal line capable of generating a signal such that when combined with the first signal line reduces a second of the at least one undesired signal components. The first signal loop may include a tunable delay enabling the generation of the signal that when combined with the first signal line reduces a first of the at least one undesired signal components. Further, the second signal loop may include a tunable delay enabling the generation of the signal that when combined with the first signal line reduces a second of the at least one undesired signal components. The first of the at least one undesired signal components may be intermodulation distortion and the adding of a signal generated by the first signal loop may reduce or eliminate it. Further, a second of the at least one undesired signal components may be receive signal distortion and the adding of a signal generated by the second signal loop may reduce or eliminate it.
| 7
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present Application for Patent claims priority to U.S. Provisional Patent Application Ser. No. 60/631,643, filed Nov. 30, 2004.
[0002] The present invention was made with support from the Defense Advanced Research Projects Agency (DARPA), under contract number N00014-04-1-0765.
FIELD OF THE INVENTION
[0003] This invention relates generally to carbon nanotubes, and specifically to methods for separating carbon nanotubes on the basis of their length.
BACKGROUND
[0004] Carbon nanotubes (CNTs), comprising multiple concentric shells and termed multi-wall carbon nanotubes (MWNTs), were discovered by Iijima in 1991 [Iijima, Nature 1991, 354, 56-58]. Subsequent to this discovery, single-wall carbon nanotubes (SWNTs), comprising single graphene sheets rolled up on themselves to form cylindrical tubes with nanoscale diameters, were synthesized in an arc-discharge process using carbon electrodes doped with transition metals [Iijima et al., Nature 1993, 363, 603-605; and Bethune et al., Nature 1993, 363, 605-607]. These carbon nanotubes (especially SWNTs) possess unique mechanical, electrical, thermal and optical properties, and such properties make them attractive for a wide variety of applications. See Baughman et al., Science, 2002, 297, 787-792.
[0005] Methods of making CNTs include the following techniques: arc discharge [Ebbesen, Annu. Rev. Mater. Sci. 1994, 24, 235-264]; laser oven [Thess et al., Science 1996, 273, 483-487]; flame synthesis [Vander Wal et al., Chem. Phys. Lett. 2001, 349, 178-184]; and chemical vapor deposition [U.S. Pat. No. 5,374,415], wherein a supported [Hafner et al., Chem. Phys. Lett. 1998, 296, 195-202] or an unsupported [Cheng et al., Chem. Phys. Lett. 1998, 289, 602-610; Nikolaev et al., Chem. Phys. Lett. 1999, 313, 91-97] metal catalyst may also be used.
[0006] Techniques of suspending and chemically functionalizing CNTs have greatly facilitated the ability to manipulate these materials, particularly for SWNTs which tend to assemble into rope-like aggregates [Thess et al., Science, 1996, 273, 483-487]. Such suspending techniques typically involve dispersal of CNTs with surfactant and/or polymer material [see Strano et al., J. Nanosci. and Nanotech., 2003, 3, 81; O'Connell et al. Chem. Phys. Lett., 2001, 342, 265-271]. Such chemical functionalization of CNTs is generally divided into two types: tube end functionalization [see, e.g., Liu et al., Science, 1998, 280, 1253-1256; Chen et al., Science, 1998, 282, 95-98], and sidewall functionalization [see, e.g., PCT publication WO 02/060812 by Tour et al.; Khabashesku et al., Acc. Chem. Res., 2002, 35, 1087-1095; and Holzinger et al., Angew. Chem. Int. Ed., 2001, 40, 4002-4005], and can serve to facilitate the debundling and dissolution of such CNTs in various solvents. Scalable chemical strategies have been, and are being, developed to scale up such chemical manipulation [Ying et al., Org. Letters, 2003, 5, 1471-1473, Bahr et al., J. Am. Chem. Soc., 2001, 123, 6536-6542; and Kamaras et al., Science, 2003, 301, 1501].
[0007] SWNTs are typically synthesized with polydisperse micrometer lengths where they are bound into microscopic entangled ropes. Many applications, however, will require short undamaged individual nanotubes 20-100 nm in length. For example, the introduction of SWNTs into electronic devices will clearly require the ability to place SWNTs of a specific band gap and precise length in a well-defined location on a substrate. Techniques have been developed for cutting SWNTs into shorter segments. See, e.g., Gu et al., Nano Lett. 2002, 2, 1009-1013; and Ziegler et al., J. Am. Chem. Soc. 2005, 127, 1541-1547. However, while these processes yield SWNTs of shorter length, they often still have significant polydispersity. Hithertofore, length-based separations of SWNTs have been limited to small-scale techniques such as chromatography and electrophoresis [Heller et al., J. Am Chem. Soc., 2004, 126, 14567-14573].
[0008] In view of the foregoing, a simpler, more scalable method of length separation would be extremely useful.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The present invention is generally directed to new liquid-liquid extraction processes for the length-based separation of carbon nanotubes (CNTs) and other 1-dimensional nanostructures.
[0010] In some embodiments, the present invention is directed to methods for separating SWNTs on the basis of their length, said methods comprising the steps of: (a) functionalizing SWNTs to form functionalized SWNTs with ionizable functional moieties; (b) dissolving said functionalized SWNTs in a polar solvent to form a polar phase; (c) dissolving a substoichiometric (relative to the amount of ionizable functional moieties present on the SWNTs) amount of a phase transfer agent in a non-polar solvent to form a non-polar phase; (d) combining the polar and non-polar phases to form a bi-phase mixture; (e) adding a cationic donor species to the bi-phase mixture; and (f) agitating the bi-phase mixture to effect the preferential transport of short SWNTs into the non-polar phase such that the non-polar phase is enriched in short SWNTs and the polar phase is enriched in longer SWNTs. In other embodiments, analogous methods are used for the length-based separation of any type of CNT, and more generally, for any type of 1-dimensional nanostructure.
[0011] It is important to point out that in any of the embodiments described herein, the terms “long” or “longer” and “short” or “shorter,” as they relate to CNTs and other 1-dimensional nanostructures, are relative terms reflective of a material initially having a polydispersity of lengths that is subjected to length-based separation. Upon being subjected to such a length-based separation, the CNTs in one phase will be, on average, longer than the CNTs in the other phase.
[0012] The foregoing has outlined rather broadly the features of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0014] FIGS. 1 a - 1 d are AFM images of the functionalized SWNTs (a) before extraction; and after partial extraction with TOAB corresponding to ion-pairing of (b) 30%, (c) 60%, and (d) 75%.
[0015] FIGS. 2 a - 2 e depict length distributions of the functionalized SWNTs (a) before extraction; and after partial extraction with TOAB corresponding to ion-pairing of (b) 30%, (c) 40%, (d) 60%, and (e) 75%. The dashed lines indicate the average length of the sample.
[0016] FIG. 3 is a plot of average length of the nanotubes extracted as a function of ion-pairing (circles). The starting material is shown on the plot at 100% (square) to demonstrate that the lengths extracted approaches complete extraction.
DETAILED DESCRIPTION OF THE INVENTION
[0017] This invention is directed to new liquid-liquid extraction processes for the length-based separation of carbon nanotubes and other 1-dimensional nanostructures. Generally, such processes are easily scalable and overcome many of the limitations seen in the prior art. Furthermore, the separated carbon nanotubes are easily collected and purified to a pristine state.
[0018] Carbon nanotubes (CNTs), as defined herein, include multi-wall carbon nanotubes (MWNTs), single-wall carbon nanotubes (SWNTs), small-diameter (<3 nm) carbon nanotubes, double-wall carbon nanotubes, and combinations thereof. The CNTs can be made by any known method and can be subjected to one or more processing techniques prior to being subjected to the methods of the present invention.
[0019] While inclusive of CNTs, 1-dimensional nanostructures, as defined herein, generally refer to structures that are nanosized (1-100 nm) in at least two dimensions. Such structures include, but are not limited to, nanotubes, nanorods, and nanowires.
[0020] In some embodiments, pristine SWNTs are first functionalized with an ionizable moiety such as chlorobenzenesulfonic acid groups. See, e.g., Hudson et al., J. Am. Chem. Soc., 2004, 126, 11158-11159. These functionalized tubes have high solubility in water (0.20 mg/mL) and other polar solvents (e.g., methanol, ethanol). The nanotubes are dissolved in water and placed in an extraction vessel. Then, a solution of tetraoctylammonium bromide (TOAB), a common phase transfer catalyst (agent), is prepared in an organic solvent (e.g., ethyl acetate or toluene). This solution is added to the extraction vessel resulting in a liquid-liquid phase system. The extraction vessel is shaken vigorously to increase interfacial area and assist transfer across the interface. The resultant mixture is filled with gray emulsions. When ethyl acetate is used as the organic solvent, the emulsions are very fine with the swollen water phase occupying almost the entire liquid volume. The emulsions settle slowly (over ˜2 hours) still giving a water phase swollen with emulsions. The extraction vessel is then placed in a freezer overnight and then allowed to thaw. Upon gentle agitation, the presence of carbon nanotubes is evident in the upper phase. When toluene is used as the organic solvent, the emulsions are coarser than for ethyl acetate, and settle more quickly (˜5 seconds) giving a swollen, emulsion-filled water phase. Complete extraction of the nanotubes is achieved when a molar excess of TOAB is utilized. Under TOAB-starved conditions (i.e., a molar ratio less than 1 of TOAB to chlorobenzenesulfonic acid groups), Applicants find that the shortest nanotubes in the sample are being extracted. Applicants have varied the TOAB concentration and found that the length of SWNTs transferred from the water to the organic phase is indeed dependent on TOAB concentration.
[0021] The extraction of SWNTs from the water phase to the organic phase is also reversible. After the extraction, the SWNTs are complexed with TOA + cations and NH 4 + cations in the organic phase. These cationic ligands can be de-complexed with the addition of excess acetic acid. In the presence of excess acetic acid, the TOA + will preferentially bind to the acetate anions. The mixture is then filtered, the solids are placed in water, methanol, or ethanol and sonicated for ˜1 minute to obtain re-suspension in the polar solvent.
[0022] While not intending to be bound by theory, the proposed mechanism of phase transfer is due to the TOA + coupling with the sulfonate anion via a one-to-one electrostatic interaction. Under TOAB excess, the presence of TOAB on the SWNTs provides the nanotubes with sufficient organophilic nature to transfer them to the organic phase. However, at intermediate concentrations, where the TOA + does not couple with every sulfonate anion, the presence of the remaining negative charges will preclude phase transfer of SWNTs. Therefore, salts such as ammonium chloride are required to charge neutralize the remaining sulfonate anions. These salts should be chosen to effectively neutralize the surface without increased organophilicity. In the TOAB-starved conditions, where the sulfonate groups on the SWNTs are partially complexed with TOA + cations and partially complexed with NH 4 + cations, length selective extraction occurs. This length-based extraction can be understood in terms of the attractive interactions between colloidal particles and the steric repulsion interactions that occur with a brush layer attached to the colloids. Pair-wise summation of the van der Waals attractions results in significantly larger interactions for larger colloidal particles. In Applicants' system, the attractive forces of the rigid rods scale with the length of the nanotube. Therefore, the longer nanotubes have greater van der Waals interactions than shorter nanotubes. Under poor solvent conditions, or in the case of poor (hindered) ion-pairing of the organophilic TOA + , there will be poor ligand-solvent interactions leading to reduced steric forces. Thus, longer nanotubes will aggregate, excluding them from the organic phase. However, the smaller nanotubes will have sufficient steric interactions from the TOA + to render them soluble in the organic layer.
[0023] As described above, the availability of SWNT samples of uniform length is essential to many specialized applications. One such application is molecular electronics, in which a nanotube of a very specific length may be needed as a wire to make an electrical connection. Similar electronic applications involve the use of nanotubes as field emission devices and in applications utilizing their semiconducting abilities. Length specific SWNTs are also essential for biological applications such as imaging and sensing. Nanotubes of specific, small lengths are likely to be necessary to penetrate cells and to serve as biological markers. Yet another application requiring SWNTs of specific length is scanning probe microscopy where they are used as scanning probe tips.
[0024] In addition to the above-described applications, the isolation of the shortest tubes in a sample is particularly useful for another commonly-assigned technology: the SWNT amplifier. See Smalley et al., “Amplification of Single Wall Carbon Nanotubes,” PCT Patent Application Serial No. US04/34002, filed Oct. 14, 2004. The amplifier will grow long SWNTs from shorter SWNTs in the gas phase. Successful implementation of this technology requires a high solubility of SWNTs in a carrier solvent. As pointed out above, this will clearly be dependent on the length of the SWNT. Therefore, the amplifier will give the highest yield when short nanotubes (e.g., 10-60 nm in length) are fed to the reactor, thereby requiring their separation from the longer nanotubes prior to injection into the reactor.
[0025] The present invention provides the first easily scalable length-based extraction procedure for carbon nanotubes. Existing techniques are done on either an analytical or preparative scale, such as size exclusion chromatography, high performance liquid chromatography, ion exchange chromatography, capillary electrophoresis, and field flow fractionation. As Applicants' technique is a liquid-liquid extraction procedure, it can be applied on an industrial scale. In addition, Applicants' procedure can handle concentrated nanotubes in water (0.20 mg/mL) without the presence of any surfactants. Existing methods use SWNTs suspended in water with the aid of surfactants such as sodium dodecyl sulfate (SDS) and Triton X-100, further complicating separation by the need to separate the surfactants from the SWNTs. Yet another novel feature of the herein described extraction processes is their reversibility. The SWNTs complexed with TOA + cations and NH 4 + cations in the organic phase can be resuspended in a polar solvent by de-complexing the attached ligands with an excess of acetic acid.
[0026] The initial formation of stable emulsions, upon mixing of the organic and aqueous layers, is crucial in the generation of enough surface area to elicit phase transfer. However the persistence of these emulsions can make biphasic separation difficult. Applicants have found freezing overnight and thawing to be relatively effective at breaking these emulsions.
[0027] A variation (i.e., alternate embodiment) on the above-described process is the use of SWNTs (or other CNTs) functionalized with carboxylic acid-containing functional groups rather than sulfonate functional groups. Assuming these SWNTs are soluble in water, the above-described extraction procedure could easily be carried out since TOA + is known to readily complex with carboxylate anions. In fact, the use of the carboxylic acid-containing SWNTs has potential advantages over the sulfonate groups. The carboxylic acids are much less acidic than sulfonic acid, meaning that the level of protonation of the carboxyl groups can easily be controlled with pH. In one sense, protonation can be used to reverse the phase transfer or to alter the needed concentrations of TOAB to elicit phase transfer. Additionally, with fewer negatively charged ions on the SWNT surfaces, there should theoretically be fewer problems with emulsion formation as is seen in the above-described cases with sulfonate-modified tubes. Other functional groups that contain anions are also plausible variations.
[0028] The extraction process is capable of many variations. There are a wide range of phase transfer catalysts such as quaternary onium salts, crown ethers, etc. These catalysts can be asymmetric or symmetric. The counter anion used can also be varied. In addition, the salt (cationic donor species) added to the aqueous phase used to passivate the remaining charges on the nanotube can be varied and may even include the use of less organophilic phase transfer catalysts to assist the transfer of the SWNTs to the organic phase. The organic phase can be exchanged for virtually any solvent that has at least limited solubility of the phase transfer catalyst and results in extraction of the nanotubes. In fact, any two phase system may be utilized for the extraction of the SWNTs where the use of a phase transfer catalyst is utilized in transferring the SWNTs from one phase to another. Any number of common methods utilized to reduce emulsion formation or stability such as deemulsifiers or centrifugation may also be utilized in addition to, or in lieu of, freezing.
[0029] As mentioned previously, it is important to emphasize that while the discussion herein has been directed to SWNTs, such length-based methods of separating can generally be applied to any type of 1-dimensional structures-to the extent that they can be sufficiently functionalized with ionizable moieties.
[0030] The following examples are provided to demonstrate particular embodiments of the present invention. It should be appreciated by those of skill in the art that the methods disclosed in the examples which follow merely represent exemplary embodiments of the present invention. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments described and still obtain a like or similar result without departing from the spirit and scope of the present invention.
EXAMPLE 1
[0031] This Example serves to illustrate a typical extraction procedure in accordance with some embodiments of the present invention.
[0032] Approximately 100 mg of SWNTs were sidewall functionalized with chlorobenzenesulfonic acid groups according to a published procedure (Hudson et al., J. Am. Chem. Soc. 2004, 126, (36), 11158-11159). These functionalized SWNTs were then dissolved in nanopure water (0.04 mg/mL) and a 5 mL aliquot of this solution is placed in a scintillation vial 1 . Next, TOAB was dissolved in ethyl acetate or toluene to achieve a concentration 2−4×10 −5 M (in a molar ratio less than 1 with respect to chlorobenzenesulfonic acid groups) and a 5 mL aliquot was added to scintillation vial 1 . Note that the concentration of TOAB chosen will determine the number of fractions obtained from the extraction. A 50 μL aliquot of NH 4 Cl solution (10× molar excess with respect to the chlorobenzenesulfonic acid groups) was then added to vial 1 . The vial was then shaken vigorously by hand for 30 seconds. After shaking, the vial was placed in a freezer overnight. The following day, it was thawed and swirled gently. The organic layer (enriched in short SWNTs) was collected in another scintiallation vial 2 and mixed with an excess of acetic acid (e.g., 2×v/v). The contents of this vial were swirled vigorously for ˜20 seconds. The organic layer was then filtered through a 0.2 μm Teflon filter. The solid residue (short SWNTs) was collected and placed in a scintillation vial 3 with a polar solvent. This scintillation vial was sonicated for 1 minute to obtain a good suspension. Another 5 mL aliquot of TOAB in ethyl acetate or toluene of the same concentration chosen above was added to scintillation vial 1 and the extraction steps were repeated to obtain the next fraction. This process can be repeated until all SWNTs are extracted from vial 1 , which occurs once a 1:1 molar ratio of TOAB: sulfonate groups is achieved.
EXAMPLE 2
[0033] This Example serves to illustrate how atomic force microscopy (AFM) can be used to evaluate the lengths of SWNTs that have been subjected to length-based separation methods of the present invention. Such methods are further illustrated in Ziegler et al., “Length-Dependent Extraction of Single-Walled Carbon Nanotubes,” Nano Lett. (in press), DOI: 10.1021/n10510208.
[0034] For length measurements of SWNTs extracted into a non-polar organic layer, the organic phase was collected, washed with acetic acid, and re-suspended in methanol after ultrasonication for 1 min. The extracted nanotube solutions were then spin-coated onto freshly cleaved mica substrates yielding a high quantity of individual nanotubes. FIG. 1 shows tapping mode AFM images (Digital Instruments Nanoscope IIIA) and FIG. 2 shows the length distributions obtained using SIMAGIS software for the starting material and for extractions at stoichiometric ratios (TOAB: SO 3 − ) of 0.3, 0.4, 0.6 and 0.75. Only individual nanotubes were utilized for length measurements. Typically, over 1500 nanotubes were measured to obtain statistically meaningful results. The starting material ( FIG. 1 a and FIG. 2 a ) has a broad distribution of nanotube lengths with an average of 275 nm. The addition of enough TOAB to complex 30% of all SO 3 − moieties with TOA + results in only very short nanotubes being extracted into the organic layer as seen by the AFM and corresponding histograms ( FIG. 1 b and FIG. 2 b ). As can be seen, the length distribution narrows considerably with 81 % below 100 nm and an average length of 73 nm. Increased ion-pairing results in longer nanotubes being extracted. After 75% of the SO 3 − moieties are ion-paired, the length distribution begins to approach that of the starting material. FIG. 3 shows the average length of the extracted nanotubes as a function of ion-pairing. It is evident that the average length increases monotonically with TOAB concentration and approaches the average length of the starting material (square symbol in figure).
[0035] All patents and publications referenced herein are hereby incorporated by reference. It will be understood that certain of the above-described structures, functions, and operations of the above-described embodiments are not necessary to practice the present invention and are included in the description simply for completeness of an exemplary embodiment or embodiments. In addition, it will be understood that specific structures, functions, and operations set forth in the above-described referenced patents and publications can be practiced in conjunction with the present invention, but they are not essential to its practice. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without actually departing from the spirit and scope of the present invention as defined by the appended claims.
|
The present invention is generally directed to new liquid-liquid extraction methods for the length-based separation of carbon nanotubes (CNTs) and other 1-dimensional nanostructures. In some embodiments, such methods are directed to separating SWNTs on the basis of their length, wherein such methods comprise the steps of: (a) functionalizing SWNTs to form functionalized SWNTs with ionizable functional moieties; (b) dissolving said functionalized SWNTs in a polar solvent to form a polar phase; (c) dissolving a substoichiometric (relative to the amount of ionizable functional moieties present on the SWNTs) amount of a phase transfer agent in a non-polar solvent to form a non-polar phase; (d) combining the polar and non-polar phases to form a bi-phase mixture; (e) adding a cationic donor species to the bi-phase mixture; and (f) agitating the bi-phase mixture to effect the preferential transport of short SWNTs into the non-polar phase such that the non-polar phase is enriched in short SWNTs and the polar phase is enriched in longer SWNTs. In other embodiments, analogous methods are used for the length-based separation of any type of CNT, and more generally, for any type of 1-dimensional nanostructure.
| 1
|
TECHNICAL FIELD
The present invention relates to a medical device. In particular, the present invention relates to a medical device excellent in facile lubrication, having a coating which swells in the presence of an aqueous medium and which undergoes a decrease in the coefficient of friction in accordance therewith.
BACKGROUND OF THE INVENTION
Medical devices such as guide wires and various catheters, which have been hitherto used by being inserted or pierced into a living body, have a surface formed of a resin such as silicon resin, polyurethane, and vinyl chloride resin. When the medical device having a tubular or rod-shaped configuration provided with such a surface is inserted into the body, it is difficult to make insertion because of an extremely large frictional resistance. Therefore, problems arise, for example, in that the living body suffers from a great deal of pain, and mucous membrane and tissue are damaged.
In order to obviate on the foregoing drawbacks, it is known that the surface of the medical device as described above is treated such that a low friction material such as a fluororesin is used therefor, or a hydrophilic macromolecule or a lubricant such as Xylocaine jelly and olive oil is applied thereto. However, even when fluororesin is used, the friction is not sufficiently reduced when the medical device is inserted into the living body. When the lubricant is applied, the lubricant flows out within an extremely short period of time. Therefore, it is impossible to obtain a sufficient effect.
Taking notice of the fact that the hydrophilic high-molecular compound swells in the presence of an aqueous medium, and the coefficient of friction is decreased in accordance therewith, Japanese Laid-Open Patent Publication No. 6-7426 discloses that the surface of a medical device is coated, for example, with a polymer composed of maleic anhydride. However, in this method, the surface of the medical device is merely coated with the water-soluble macromolecule. Therefore, the hydrophilic macromolecule tends to be eluted from the surface, which is not desirable from a viewpoint of safety. Further, the effect to reduce the friction does not continue for a long period of time.
Japanese Laid-Open Patent Publication No. 3-184557 discloses that a hydrophilic vinyl monomer is graft-copolymerized on a surface layer of a medical device. In this method, the improvement is made in that the elution of the water-soluble macromolecule is suppressed, however, a product obtained by the graft polymerization does not have a high molecular weight. Therefore, it is impossible to obtain a sufficient effect to decrease the friction.
Each of Japanese Laid-Open Patent Publication Nos. 54-29343 and 58-193767 discloses a medical device coated with an N-vinylpyrrolidone polymer by the aid of an isocyanate group. However, a problem of elution of the polymer also arises.
Japanese Laid-Open Patent Publication No. 63-238170 discloses a medical device in which a copolymer composed of an active hydrogen-containing monomer and N-vinylpyrrolidone is coupled to a base material through an isocyanate group, and Japanese Patent Publication No. 1-33181 discloses a medical device in which a copolymer composed of maleic anhydride and methyl vinyl ether is coupled to a base material through an isocyanate group. The improvement is made from a viewpoint of elution, because these compounds form chemical bonds. However, the copolymer composed of maleic anhydride and methyl vinyl ether is hydrolyzed upon contact with water. As a result, maleic acid is produced from maleic anhydride, and the surface of the medical device becomes extremely strongly anionic. Therefore, the compound is not preferred from a viewpoint of biocompatibility. Further, the hydrophilic property is insufficient, and it is impossible to expect a sufficient effect to reduce the friction, because methyl vinyl ether which is not hydrophilic is contained in an amount of 50%. Both of the copolymer composed of the active hydrogen-containing monomer and N-vinylpyrrolidone and the copolymer composed of maleic acid and methyl vinyl ether have low flexibility, and hence they have low film strength. Accordingly, they have a drawback that the surface is easily peeled off when it undergoes friction.
As described above, the conventional method has failed to provide a medical material in which the coefficient of friction is safely reduced while suppressing the elution of macromolecule existing on the surface of the base material.
SUMMARY OF THE INVENTION
The present invention has been made taking the foregoing circumstances into consideration, an object of which is to provide a medical device in which the coefficient of friction is reduced in the presence of an aqueous medium, and the elution of a hydrophilic macromolecule existing on the surface of the medical device is suppressed, when the medical device is inserted or pierced into a living body.
As a result of investigations performed by the present inventors in order to achieve the object described above, it has been found out that a medical device, which is obtained by coupling a macromolecule composed of N-substituted alkylamide to a surface of a base material for constructing the medical device in accordance with a specified reaction, makes it possible to reduce the coefficient of friction upon insertion into a living body, and decrease the elution of the macromolecule existing on the surface of the base material. Thus, the present invention has been completed.
That is, according to the gist or feature of the present invention, there is provided a medical device comprising a base material for constructing the medical device, and a high-molecular weight compound composed of N-substituted alkylacrylamide coupled to a surface of the base material by the aid of chemical bond, wherein the chemical bond is formed by a reaction between a reactive functional group (hereinafter referred to as "first reactive functional group") which is selected from the group consisting of isocyanate group, epoxy group, and aldehyde group and a functional group (hereinafter referred to as "second reactive functional group") which is reactive with the first reactive functional group, the first reactive functional group originates from the surface of the base material, and the second reactive functional group originates from the high-molecular weight compound composed of the N-substituted alkylacrylamide.
The present invention will be explained in further detail below.
The medical device according to the present invention may be directed to any one of those contact with tissue of living bodies, mucous membrane, and blood. Those preferably directed are guide wires and catheters, and those more preferably directed are catheters.
Specifically, the catheter includes, for example, catheters to be orally or nasogastrically inserted into or retained at the inside of digestive tract, such as stomach tube catheter, nutrition catheter, and ED tube (for nutrition through tract); catheters to be inserted into or retained at the inside of trachea, such as oxygen catheter, oxygen cannula, intratracheal tube and cuff, tracheostomy tube, and intratracheal suction catheter; catheters to be inserted into or retained at the inside of urethra such as urine-introducing catheter and urethra catheter; catheters to be inserted into or retained at the inside of blood vessel, such as indwelling needle, IVH catheter, angiography catheter, thermodilution catheter, dilator, and introducer; and catheters to be inserted into or retained at the inside of various body cavities and tissues, such as suction catheter, discharge catheter, and rectum catheter.
In the present invention, it is necessary that the reactive functional group ("first reactive functional group") selected from the group consisting of isocyanate group, epoxy group, and aldehyde group exists on the surface of the base material for constructing the medical device.
In the present invention, it is necessary that the high-molecular weight compound composed of N-substituted alkylacrylamide is coupled to the surface of the base material for constructing the medical device through the chemical bond. The chemical bond results from, for example, the chemical reaction between the first reactive functional group selected from the group consisting of isocyanate group, epoxy group, and aldehyde group and the second reactive functional group which is reactive with the first reactive functional group. In this aspect, the first reactive functional group is allowed to exist on the surface of the base material, and the second reactive functional group is allowed to exist on the high-molecular compound weight composed of the N-substituted alkylacrylamide.
The method for allowing the first reactive functional group to exist on the surface of the base material for constructing the medical device includes, for example, a method in which the base material itself for constructing the medical device is previously produced by using the high-molecular weight compound-weight having the reactive functional group, and a method in which production is carried out by reacting the base material for constructing the medical device with a reactive substance having the first reactive functional group (hereinafter simply referred to as "reactive substance", if necessary). Especially, it is preferable to use the method in which the reactive substance is allowed to react with the base material for constructing the medical device.
Those usable as the reactive substance include, for example, polyisocyanates having two or more functional groups, epoxy group-containing compounds having reactive groups, and polyaldehydes having two or more functional groups. Especially, it is preferable to use the polyisocyanates having two or more functional groups.
The polyisocyanate includes, for example, ethylene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, cyclohexylene diisocyanate, triphenylmethane triisocyanate, toluene triisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane, and adducts and prepolymers of the polyisocyanates and polyols.
The epoxy group-containing compound having the reactivity includes, for example, diepoxybutane, 1,2-diepoxy-3-chloropropane.
The polyaldehyde includes, for example, terephthalaldehyde, isophthalaldehyde, glyoxal, starch, malonaldehyde, succinaldehyde, glutaraldehyde, and adipic aldehyde.
The reactive substance may be reacted with the base material for constructing the medical device as follows. That is, when the base material, which has a residue such as amino group on the surface, is used, the reactive substance may be reacted with the base material as it is, for example, by means of immersion. However, when the base material, which scarcely has such a residue on the surface, is used, a method is adopted, in which the base material is coated with a high-molecular compound having such a residue, and then the reactive substance is allowed to react therewith.
The residue is herein represented by a group which has the reactivity with the second reactive functional group described later on possessed by the high-molecular weight compound composed of N-substituted alkylacrylamide.
The base material having the residue includes, for example, those made of polyurethane and polyamide. The base material having no residue includes, for example, those made of polyethylene, polyvinyl chloride, fluororesin, and silicon. Those preferably used as the high-molecular weight compound containing the residue for coating the medical device having no residue therewith include, for example, polyurethane and polyamide.
In the present invention, the high-molecular weight compound composed of N-substituted alkylacrylamide has the functional group ("second reactive functional group") which is reactive with the first reactive functional group existing on the surface of the base material for constructing the medical device. Those preferably used as the high-molecular weight compound as described above include, for example, a copolymer of N-substituted alkylacrylamide and a monomer having the second reactive functional group (hereinafter referred to as "functional group-containing monomer", if necessary).
Those preferably used as N-substituted alkylacrylamide described above include those in which the alkyl group has a number of carbon or carbons of 1 to 4. Those more preferably used as N-substituted alkylacrylamide described above include N,N-dialkylacrylamide in which the alkyl group has a number of carbon or carbons of 1 to 4.
Specifically, the N-substituted alkylacrylamide as described above includes, for example, N-methylacrylamide, N-ethylacrylamide, N-propylacrylamide, N-butylacrylamide, N,N-dimethylacrylamide, and N,N-diethylacrylamide. Especially, N,N-dialkylacrylamide is preferably used. In particular, N,N-dimethylacrylamide is more preferably used.
The N-substituted alkylacrylamide may be used singly or in combination of two or more species. When two or more species of the N-substituted alkylacrylamides are used, one of them is preferably N,N-dialkylacrylamide.
The functional group-containing monomer includes, for example, vinyl type monomers having a functional group such as hydroxyl group, amino group, and carboxyl group. Specifically, for example, there are exemplified hydroxyethyl acrylate, hydroxyethyl methacrylate, and acrylamide. It is preferable to use hydroxyethyl methacrylate and hydroxyethyl acrylate. One of them may be used to provide the copolymer with N-substituted alkylacrylamide. Alternatively, two or more of them may be used.
The functional group-containing monomer is ordinarily contained in the high-molecular weight compound composed of N-substituted alkylacrylamide in a ratio of 0.01 to 15 mole %, preferably 0.01 to 8 mole %, and more preferably 0.05 to 5 mole %. If the ratio of the monomer is too small, the coupling becomes insufficient. If the ratio is too large, no sufficient hydration can be obtained, because the degree of freedom of the molecular chain is decreased. Further, the flexibility of a formed coating disappears, and hence the friction is not reduced sufficiently. Moreover, the film tends to be peeled of in some cases.
N-substituted alkylacrylamide and a monomer other than the functional group-containing monomer may be used together as constitutive components for the high-molecular weight compound composed of N-substituted alkylacrylamide. Such a monomer is not specifically limited provided that the monomer can be subjected to copolymerization. However, in order to improve the flexibility of the coating formed by the high-molecular weight compound composed of N-substituted alkylacrylamide, it is preferable to use a monomer having a property to give flexibility. When such a monomer is used together, it is possible to avoid occurrence of fine irregularities on the surface of the coating. The fine irregularities on the surface of the coating are not preferred, because they induce increase in frictional force as well as formation of thrombus.
Those used as the monomer having the property to add flexibility (hereinafter referred to as "flexibility-adding monomer", if necessary) includes, for example, diacetone acrylamide, acrylic acid, methacrylic acid, ester of acrylic acid and alcohol having a number of carbon or carbons of 1 to 12, ester of methacrylic acid and alcohol having a number of carbon or carbons of 1 to 12, and vinyl ester. The monomer may be used singly, or two or more of the monomers may be used in combination. Those preferably used as the ester of acrylic acid or methacrylic acid and alcohol having a number of carbon or carbons of 1 to 12 include ester of acrylic acid or methacrylic acid and alcohol having a number of carbon or carbons of 1 to 8. Specifically, there are exemplified ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, methyl acrylate, and methyl methacrylate. The vinyl ester may be exemplified by vinyl acetate and vinyl propionate. Preferably, vinyl acetate is used. Among the monomers, it is preferable to use diacetone acrylamide, methyl methacrylate, and ethyl acrylate.
The monomer to give flexibility is ordinarily used in the high-molecular weight compound composed of N-substituted alkylacrylamide in a ratio of 0.01 to 10 mole %, and preferably 0.2 to 8 mole %. If the amount of the monomer is too small, it is impossible to sufficiently suppress formation of irregularities of the coating. If the amount of the monomer is too large, the monomer causes increase in friction in water in some cases.
The high-molecular weight compound composed of N-substituted alkylacrylamide is obtained by polymerizing N-substituted alkylacrylamide, the monomer having the second reactive functional group, and optionally the flexibility-adding monomer, in accordance with an ordinary method. For example, the high-molecular compound composed of N-substituted alkylacrylamide may be produced in accordance with any method such as anion polymerization, cation polymerization, and radical polymerization. Especially, radical polymerization is preferred. Radical polymerization may be performed, for example, in accordance with solution polymerization, emulsion polymerization, and pearl polymerization, by using a polymerization initiator of an azo compound such as azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile) or a peroxide such as benzoyl peroxide and t-butyl perpivalate. In order to obtain the high-molecular weight compound composed of N-substituted alkylacrylamide having a relatively low molecular weight, it is preferable to perform polymerization in a ketone solvent such as ethyl methyl ketone. In order to obtain the high-molecular weight compound composed of N-substituted alkylacrylamide having a relatively high molecular weight, it is preferable to perform polymerization in an aqueous solution or perform production in accordance with peal polymerization of the water-in-oil type.
Usually, those having a molecular weight of about ten thousands to ten millions are used as the high-molecular weight compound composed of N-substituted alkylacrylamide. Especially, those having a molecular weight of fifty thousands to six millions are preferably used.
When the coating of the high-molecular weight compound composed of N-substituted alkylacrylamide is formed on the base material having the residue described above, a method is used, in which the base material is coated with a solution of the reactive substance having the first reactive functional group, and then the base material is coated with a solution of the high-molecular weight compound composed of N-substituted alkylacrylamide, followed by performing a reaction to form the chemical bond. The solution of the reactive substance may contain other high-molecular weight compounds such as urethane.
When the coating of the high-molecular weight compound composed of N-substituted alkylacrylamide is formed on the base material having no residue, a method is used, in which the base material is coated with a solution obtained by dissolving, for example, polyurethane or polyamide, thereafter the base material is coated with the reactive substance, and then the base material is coated with the high-molecular weight compound composed of N-substituted alkylacrylamide, followed by performing a reaction to form the chemical bond.
Any solvent may be used when the base material is coated with the reactive substance provided that the solvent makes no reaction with the reactive substance. However, those usable as the solvent include, for example, ketone solvent such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; halogen solvent such as methylene chloride and chloroform; ester solvent such as ethyl acetate and butyl acetate; and ether solvent such as tetrahydrofuran and dioxane. Especially, it is preferable to use the ketone solvent, the halogen solvent, or a mixture thereof, because these solvents have a property to swell the high-molecular weight compound on the surface of the medical device.
In the present invention, any method which is ordinarily used may be adopted as the coating method. For example, there may be exemplified spin coat, brush painting, and immersing treatment. Preferably, the coating process is performed by means of the immersing treatment.
The reaction between the second reactive functional group possessed by the high-molecular weight compound composed of N-substituted alkylacrylamide and the first reactive functional group existing on the surface of the base material for constructing the medical device is achieved by coating the base material with the high-molecular weight compound composed of N-substituted alkylacrylamide, and then performing heating. The heating temperature is usually within a range of 40° C. to 100° C., and preferably 50° C. to 90° C. The heating time is usually within a range of 60 to 300 minutes, preferably 60 to 240 minutes.
According to the present invention, it is possible to provide the medical device excellent in safety in which the coefficient of friction is small when the medical device is inserted or pierced into a living body, and the elution of the hydrophilic macromolecule existing on the surface of the medical device is suppressed.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will be explained in further detail below with reference to Examples. However, the present invention is not limited to the following Examples, which may take other various forms without deviating from the gist or essential characteristics thereof.
EXAMPLE 1
1.94 g of N,N-dimethylacrylamide and 0.076 g of hydroxyethyl methacrylate (hereinafter abbreviated as "HEMA", if necessary) as a functional group-containing monomer were mixed with 1,4-dioxane containing 0.24% by weight of N,N'-azobisisobutylonitrile. An obtained mixture solution was placed in a sealed tube. The gas phase was substituted with nitrogen, and then the sealed tube was maintained at 70° C. for 4 hours to perform polymerization. A reaction mixture was taken out of the sealed tube. An obtained polymer was precipitated with diethyl ether, followed by drying in vacuum. As a result, 1.9 g of the polymer was obtained.
EXAMPLE 2
1.952 g of N,N-dimethylacrylamide and 0.032 g of hydroxyethyl methacrylate as a functional group-containing monomer were mixed with 1,4-dioxane containing 0.24% by weight of N,N'-azobisisobutylonitrile. The obtained mixture solution was placed in a sealed tube. The gas phase was substituted with nitrogen, and then the sealed tube was maintained at 70° C. for 4 hours to perform polymerization. A reaction mixture was taken out of the sealed tube. An obtained polymer was precipitated with diethyl ether, followed by drying in vacuum. As a result, 1.95 g of the polymer was obtained.
EXAMPLE 3
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a methyl ethyl ketone solution containing 3% by weight of diphenylmethane diisocyanate for 3 minutes, followed by drying in air for 3 minutes. Subsequently, the base material was immersed in a methyl ethyl ketone solution containing 5% of the polymer obtained in Example 1 for 1 minute, followed by drying for 3 minutes. The base material and the polymer were coupled to one another by maintaining the materials for 3 hours in a hot air drier at 80° C. When the surface of an obtained coating was observed with an optical microscope, fine irregularities were found. The coefficient of dynamic friction with respect to a stainless steel surface was measured in water by using a friction meter (automatic friction/wearing analyzer "DFPM-SS Type" produced by Kyowa Interface Scientific). The coefficient of friction was 0.030 which was low. The coefficient of friction was not changed even after being maintained for 1 week in water. No peeled-off coating was observed even after being rubbed with fingers.
Summarized results are shown in Table 1. The property of the surface shown in the table is represented as follows; A: there were few irregularities on the surface of the coating, B: fine irregularities were found on the surface of the coating, and C: cracks appeared on the coating.
EXAMPLE 4
Experiment was carried out in the same manner as in Example 3 except that the polymer obtained in Example 2 was used in place of the polymer obtained in Example 1. Fine irregularities were found on the surface of the coating. The coefficient of dynamic friction was 0.032. The coefficient of friction was not changed even after being maintained in water for 1 week. No peeled-off coating was observed even after being rubbed with fingers.
COMPARATIVE EXAMPLE 1
Experiment was carried out in the same manner as in Example 3 except that poly(N-vinylpyrrolidone) (produced by BASF, trade name: "Povidone K-90") was used in place of the polymer obtained in Example 1. The coefficient of dynamic friction obtained immediately after being placed in water was 0.08. However, when the obtained product was maintained in water for 1 week, peeled-off coating was observed. The coating was easily peeled off when it was merely rubbed with fingers.
COMPARATIVE EXAMPLE 2
Experiment was carried out in the same manner as in Example 3 except that a copolymer of maleic anhydride and methyl vinyl ether (produced by ISP Investment, trade name: "GANTREZ AN-169") was used in place of the polymer obtained in Example 1. The coefficient of dynamic friction obtained immediately after being placed in water was 0.07. However, when the obtained product was maintained in water for 1 week, peeled-off coating was observed. The coating was easily peeled off when it was merely rubbed with fingers.
EXAMPLE 5
2.005 g of N,N-dimethylacrylamide and 0.0067 g of hydroxyethyl methacrylate as a functional group-containing monomer were mixed with 1,4-dioxane containing 0.1% by weight of N,N'-azobisisobutylonitrile. An obtained mixture solution was placed in a sealed tube. The gas phase was substituted with nitrogen, and then the sealed tube was maintained at 70° C. for 7 hours. A reaction mixture was taken out of the sealed tube. An obtained polymer was precipitated with diethyl ether, followed by drying in vacuum. As a result, 1.95 g of the polymer was obtained.
EXAMPLE 6
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a methyl ethyl ketone solution containing 3% by weight of methylene diisocyanate for 1 minute. After that, the base material was taken out of the solution, followed by drying in air for 3 minutes. Subsequently, the base material was immersed in a methyl ethyl ketone solution containing 5% of the polymer obtained in Example 5 for 15 seconds, followed by drying in air for 3 minutes. After drying at 60° C. for 1 hour in a hot air drier, the base material and the polymer were coupled to one another by maintaining the materials for 1 hour in a hot air drier at 80° C.
The coefficient of friction with respect to stainless steel in water was measured in the same manner as in Example 3. As a result, the coefficient of dynamic friction was 0.017, and the coefficient of static friction was 0.023. The coefficient of friction was not changed even after being maintained for 1 week in water. No peeled-off coating was observed even after being rubbed with fingers. The surface of the coating was observed in the same manner as in Example 3. As a result, fine irregularities were found on the surface of the coating. Summarized results are shown in Table 1.
EXAMPLES 7 AND 8
Experiment was carried out in the same manner as in Example 5 except that the amounts of N,N-dimethylacrylamide and hydroxyethyl methacrylate were changed as shown in Table 1. An obtained polymer was coupled to the urethane film in accordance with the same method as used in Example 6. Physical properties were measured in the same manner as in Example 3. Results are shown in Table 1.
EXAMPLE 9
1.9928 g of N,N-dimethylacrylamide and 0.0142 g of acrylamide (hereinafter abbreviated as "AAM", if necessary) as a functional group-containing monomer were mixed with 3 g of 1,4-dioxane containing 0.1% by weight of N,N'-azobisisobutylonitrile. An obtained mixture solution was placed in a sealed tube. The gas phase was substituted with nitrogen, and then the sealed tube was maintained at 70° C. for 7 hours. A reaction mixture was taken out of the sealed tube. An obtained polymer was precipitated with diethyl ether, followed by drying in vacuum. As a result, 1.87 g of the polymer was obtained. The obtained polymer was coupled to the urethane film in the same manner as in Example 6. Physical properties were measured in the same manner as in Example 3. Results are shown in Table 1.
EXAMPLES 10 AND 11
Experiment was carried out in the same manner as in Example 9 except that the amounts of N,N-dimethylacrylamide and acrylamide were changed as shown in Table 1. Results are shown in Table 1.
TABLE 1__________________________________________________________________________Functionalgroup- Flexibility-containing adding Coefficient Coefficientmonomer monomer of static of dynamic SurfaceType mol % Type mol % friction friction property__________________________________________________________________________Ex. 1,3 HEMA 2.90 NON -- -- 0.030 BEx. 2,4 HEMA 1.23 NON -- -- 0.032 BEx. 5,6 HEMA 0.25 NON -- 0.023 0.017 BEx. 7 HEMA 0.50 NON -- 0.028 0.018 BEx. 8 HEMA 1.01 NON -- 0.032 0.025 BEx. 9 AAM 0.98 NON -- 0.0255 0.0213 BEx. 10 AAM 1.95 NON -- 0.0202 0.0135 BEx. 11 AAM 3.92 NON -- 0.0003 0.0000 B__________________________________________________________________________ HEMA: hydroxyethyl methacrylate AAM: acrylamide
EXAMPLE 12
1.9097 g of N,N-dimethylacrylamide, 0.0484 g of hydroxyethyl methacrylate as a functional group-containing monomer, and 0.0344 g of diacetone acrylamide as a flexibility-adding monomer were mixed with 3 g of 1,4-dioxane containing 0.1% by weight of N,N'-azobisisobutylonitrile. An obtained mixture solution was placed in a sealed tube. The gas phase was substituted with nitrogen, and then the sealed tube was maintained at 70° C. for 7 hours. A reaction mixture was taken out of the sealed tube. An obtained polymer was precipitated with diethyl ether, followed by drying in vacuum. As a result, 1.9137 g of the polymer was obtained. The obtained polymer was coupled to the urethane film in the same manner as in Example 6. Physical properties were measured in the same manner as in Example 3. Results are shown in Table 2.
EXAMPLES 13 TO 19
Experiment was carried out in the same manner as in Example 12 except that the amounts of N,N-dimethylacrylamide, hydroxyethyl methacrylate, and diacetone acrylamide were changed as shown in Table 2. Results are shown in Table 2.
TABLE 2__________________________________________________________________________Functionalgroup- Flexibility-containing adding Coefficient Coefficientmonomer monomer of static of dynamic SurfaceType mol % Type mol % friction friction property__________________________________________________________________________Ex. 12 HEMA 1.88 DAA 1.02 0.036 0.019 AEx. 13 HEMA 1.87 DAA 1.97 0.038 0.016 AEx. 14 HEMA 1.96 DAA 4.05 0.033 0.016 AEx. 15 HEMA 1.92 DAA 7.99 0.035 0.021 AEx. 16 HEMA 0.51 DAA 0.49 0.019 0.007 AEx. 17 HEMA 0.53 DAA 1.04 0.016 0.004 AEx. 18 HEMA 0.50 DAA 1.97 0.016 0.005 AEx. 19 HEMA 0.51 DAA 3.94 0.017 0.006 A__________________________________________________________________________ DAA: diacetone acrylamide
EXAMPLES 20 TO 31
Experiment was carried out in the same manner as in Example 9 by using N,N-dimethylacrylamide except that hydroxyethyl methacrylate was used as a functional group-containing monomer, any one of acrylic acid, ethyl acrylate, and vinyl acetate was used as a flexibility-adding monomer, and the amounts of the respective components were changed as shown in Table 3 and Table 4. Results are shown in Table 3 and Table 4.
TABLE 3__________________________________________________________________________Functionalgroup- Flexibility-containing adding Coefficient Coefficientmonomer monomer of static of dynamic SurfaceType mol % Type mol % friction friction property__________________________________________________________________________Ex. 20 HEMA 0.64 AcA 1.98 0.0059 0.0013 AEx. 21 HEMA 0.50 AcA 4.01 0.0126 0.0066 AEx. 22 HEMA 0.49 EA 0.96 0.007 0.001 AEx. 23 HEMA 0.51 EA 4.04 0.005 0.001 AEx. 24 HEMA 0.50 EA 8.29 0.011 0.005 A__________________________________________________________________________ AcA: acrylic acid EA: ethyl acrylate
TABLE 4__________________________________________________________________________Functionalgroup- Flexibility-containing adding Coefficient Coefficientmonomer monomer of static of dynamic SurfaceType mol % Type mol % friction friction property__________________________________________________________________________Ex. 25 HEMA 0.49 VAc 0.91 0.006 0.001 AEx. 26 HEMA 0.49 VAc 4.09 0.030 0.022 AEx. 27 HEMA 0.50 VAc 8.12 0.020 0.016 AEx. 28 HEMA 0.29 VAc 1.17 0.014 0.010 AEx. 29 HEMA 0.29 VAc 0.59 0.017 0.012 AEx. 30 HEMA 0.29 VAc 2.28 0.020 0.013 AEx. 31 HEMA 0.32 VAc 4.34 0.018 0.012 A__________________________________________________________________________
EXAMPLES 32 TO 37
Experiment was carried out in the same manner as in Example 9 by using N,N-dimethylacrylamide except that hydroxyethyl methacrylate was used as a functional group-containing monomer, methyl methacrylate or hexyl methacrylate was used as a flexibility-adding monomer, and the amounts of the respective components were changed as shown in Table 5. Results are shown in Table 5.
TABLE 5__________________________________________________________________________Functionalgroup- Flexibility-containing adding Coefficient Coefficientmonomer monomer of static of dynamic SurfaceType mol % Type mol % friction friction property__________________________________________________________________________Ex. 32 HEMA 0.50 MMA 1.26 0.005 0 AEx. 33 HEMA 0.49 MMA 2.03 0.006 0 AEx. 34 HEMA 0.52 MMA 4.00 0.005 0 AEx. 35 HEMA 0.50 HXMA 1.06 0.009 0.002 AEx. 36 HEMA 0.49 HXMA 2.17 0.013 0.004 AEx. 37 HEMA 0.52 HXMA 4.34 0.019 0.002 A__________________________________________________________________________ MMA: methyl methacrylate HXMA: hexyl methacrylate
COMPARATIVE EXAMPLE 3
11.1 parts by weight of N-vinylpyrrolidone and 0.205 part by weight of 2-hydroxyethyl methacrylate were placed in a reaction vessel equipped with an agitator, a ball cooling tube, and a nitrogen-introducing tube, and the content was diluted with 25 parts by weight of methyl alcohol. The reaction vessel was maintained at 70° C. under a nitrogen flow, to which 5 parts by weight of methyl alcohol containing 0.05 part by weight of azobisisobutyronitrile was added. The reaction vessel was maintained at 70° C. for 6 hours while being subjected to agitation and reflux. Methyl alcohol was distilled off, and the content was dried in vacuum. An obtained polymer was dissolved in 25 parts by weight of dimethylformamide, and it was diluted with 25 parts by weight of dichloromethane.
COMPARATIVE EXAMPLE 4
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a dichloromethane solution containing 3% by weight of diphenylmethane diisocyanate for 1 minute, followed by drying in air for 10 minutes. The base material was immersed in a solution of the polymer obtained in Comparative Example 3 for 30 seconds, followed by drying in air for 10 minutes. After that, the base material was maintained at 100° C. for 20 minutes in a hot air drier, followed by drying in vacuum at 60° C. for 5 hours. The coefficient of friction in water of the obtained film was measured in the same manner as in Example 3. As a result, both of the coefficient of static friction and the coefficient of dynamic friction were 0.12. The obtained film was immersed in water for 1 week, and then the coefficient of static friction and the coefficient of dynamic friction were measured again in water. As a result, any of them increased to 0.21.
COMPARATIVE EXAMPLE 5
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in methyl ethyl ketone for 20 seconds. Subsequently, the base material was immersed in a dichloromethane solution containing 10% by weight of diphenylmethane diisocyanate for 20 seconds, followed by drying in air for 3 minutes. The base material was immersed for 40 seconds in a dichloromethane solution containing 5% by weight of polyethylene glycol (produced by Tokyo Kasei, molecular weight: 20,000), and then it was maintained at room temperature for 50 hours.
The coefficient of friction in water was measured after being maintained in water for 6 hours, in the same manner as in Example 3. As a result, the coefficient of static friction was 0.10, and the coefficient of dynamic friction were 0.10.
EXAMPLE 38
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a methyl ethyl ketone solution containing 1% by weight of diphenylmethane diisocyanate for 1 minute. After that, the base material was taken out of the solution, followed by drying in hot air at 60° C. for 1 hour. Subsequently, the base material was immersed in a methyl ethyl ketone solution containing 10% of the polymer obtained in Example 9 for 30 seconds, followed by drying in air for 3 minutes. The base material and the polymer were coupled to one another by maintaining the materials for 2 hours in a hot air drier at 80° C. Surface physical properties were measured in the same manner as in Example 3. As a result, the coefficient of dynamic friction in water was 0.005, and the coefficient of static friction was 0.007.
EXAMPLES 39 TO 42
Experiment was carried out in the same manner as in Example 38 except that the concentration of the methyl ethyl ketone solution of diphenylmethane diisocyanate was changed as shown in Table 6. Surface physical properties are shown in Table 6.
TABLE 6______________________________________ Concentration of methyl ethyl ketone solution of Coefficient Coefficient diphenylmethane of static of dynamic diisocyanate (wt %) friction friction______________________________________Example 39 0.5 0.004 0.003Example 40 2 0.017 0.014Example 41 3 0.012 0.01Example 42 5 0.01 0.009______________________________________
EXAMPLE 43
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a methyl ethyl ketone solution containing 2% by weight of diphenylmethane diisocyanate for 1 minute. After that, the base material was taken out of the solution, followed by drying in hot air at 60° C. for 1 hour. Subsequently, the base material was immersed in a methyl ethyl ketone solution containing 10% of the polymer obtained in Example 10 for 15 seconds, followed by drying in air for 3 minutes. The base material and the polymer were coupled to one another by maintaining the materials for 2 hours in a hot air drier at 60° C. Surface physical properties were measured in the same manner as in Example 3. As a result, the coefficient of dynamic friction in water was 0.008, and the coefficient of static friction was 0.013.
EXAMPLES 44, 45
Experiment was carried out in the same manner as in Example 39 except that the immersing time in the methyl ethyl ketone solution of diphenylmethane diisocyanate was changed as shown in Table 7. Surface physical properties are shown in Table 7.
TABLE 7______________________________________ Immersing time in methyl ethyl ketone solution of Coefficient Coefficient diphenylmethane of static of dynamic diisocyanate (min) friction friction______________________________________Example 44 3 0.006 0.001Example 45 5 0.026 0.015______________________________________
EXAMPLE 46
A urethane film as a base material (produced by Dow Chemical, trade name: "Pellecene") was immersed in a methyl ethyl ketone solution containing 2% by weight of diphenylmethane diisocyanate for 1 minute. After that, the base material was taken out of the solution, followed by drying in hot air at 60° C. for 1 hour. Subsequently, the base material was immersed in a methyl ethyl ketone solution containing 2% of the polymer obtained in Example 9 for 15 seconds, followed by drying in air for 3 minutes. The base material and the polymer were coupled to one another by maintaining the materials for 2 hours in a hot air drier at 60° C. Surface physical properties were measured in the same manner as in Example 3. As a result, the coefficient of dynamic friction in water was 0.009, and the coefficient of static friction was 0.023.
EXAMPLE 47
Experiment was carried out in the same manner as in Example 42 except that a methyl ethyl ketone solution containing 10% of the polymer obtained in Example 9 was used. Surface physical properties were measured in the same manner as in Example 3. As a result, the coefficient of dynamic friction in water was 0.003, and the coefficient of static friction was 0.009.
|
Disclosed is a medical device in which a surface of a base material for constructing the medical device is coupled to a high-molecular weight compound composed of N-substituted alkylacrylamide by the aid of a reaction between a reactive functional group such as isocyanate group, epoxy group, and aldehyde group existing on the surface and a functional group which is possessed by the high-molecular weight compound and which is reactive with the first reactive functional group.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from Japanese Patent Application No. 2010-290007, filed in the Japanese Patent Office on Dec. 27, 2010, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a laser lap welding method, and more particularly to a laser lap welding method which improves a hole, an indentation, and the like, which are caused at a welding terminating end.
[0003] A laser welding method, in which a laser beam is irradiated onto a workpiece to heat and melt a material of the irradiated portion by the light energy of the laser beam, has an advantage in that high speed welding can be performed in a non-contact manner, but has a problem in that a hole and an indentation are caused at a welding terminating end. Thus, the problem has become one of the factors that limit the use of the laser welding method to only some automobile parts and prevents the laser welding method from being used for into the vehicle body welding process in which strict management of performance and quality about airtightness, water leakage, and the like, is required.
[0004] Perforation and indentation, which are caused in a laser welding terminating end, are caused by molten metal supplied to the welding terminating end eventually becoming insufficient due to a phenomenon in which the molten metal flows in the direction opposite to the welding advancing direction. As a measure to solve this problem, there is known, as disclosed in JP2007-313544A, a method which is referred to as “ramping” or “fade down” and in which the laser output is controlled to be gradually reduced toward the welding terminating end.
[0005] For example, as shown in FIG. 5(A) and FIG. 5(B) , in the case in which two galvanized steel sheets 1 and 2 are overlapped and laser-welded to each other, when the laser output P is maintained at a constant level until the laser beam reaches the welding terminating end, a hole 52 is generated at the end of a weld bead 51 , and the substantial welding length Wa becomes shorter than the laser irradiation length L by the length corresponding to the hole 52 .
[0006] On the other hand, as shown by the solid line ( 61 ) in FIG. 5(C) and FIG. 5(D) , when the laser output P is gradually reduced toward the welding terminating end, since the penetration depth is gradually reduced, the frequency of occurrence of the perforation at the end of the weld bead 61 is reduced, but the perforation cannot be completely prevented. Furthermore, even in the case in which the perforation is not caused, a comparatively deep indentation 62 is left at the welding terminating end, and also the substantial welding length Wa′ is further reduced. Thus, when this welding method is used as it is, a reduction in strength, and the like, is caused at the welding terminating end, so that the welding quality is inevitably affected.
[0007] In order to avoid this problem, it is also conceivable to increase the welding length (L″) as shown by a broken line ( 71 ) in FIG. 5(C) and FIG. 5(D) . However, in this case, problems are caused in which a space required for the weld bead 71 and the cycle time are increased.
[0008] As another measure against the above-described problems, a method is disclosed in JP2008-264793A in which the laser irradiation diameter is increased at the welding terminating end by defocusing the laser beam. However, as shown in FIG. 1 of JP2008-264793A, when the laser beam is stopped and defocused at welding terminating end, burn-through may be caused instead of an improvement in the hole and indentation. Furthermore, although not clearly described in JP2008-264793A, there arises a problem that, when the defocusing operation is started just before the laser beam reaches the welding terminating end, the energy density of the laser beam is reduced and thereby the substantial welding length is reduced similarly to the case in which the above-described method is used.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention has been made in view of the above-described circumstances. An object of the present invention is to provide a laser lap welding method which does not need complicated control, such as laser focus control, and which can improve the hole and indentation at the welding terminating end while avoiding an increase in the space and the cycle time that are required to secure the welding length.
[0010] In order to solve the above-described problem, the present invention provides a laser lap welding method which includes irradiating a laser beam from one side of a plurality of overlapped workpieces, including the steps of: scanning (La) the laser beam in the forward direction along a predetermined section of the workpieces; reversing the scanning direction of the laser beam at a terminating end (t) of the predetermined section; briefly scanning (Lb) the laser beam in the backward direction and terminating the irradiating of the laser beam onto the predetermined section, wherein the scanning the laser beam in the backward direction is offset from the scanning the laser beam in the forward direction such that a part of a weld bead formed by the laser scanning in the backward direction overlaps the weld bead formed by the laser scan in the forward direction, and then terminating the irradiating of the laser beam onto the predetermined section.
[0011] It has already been described that the occurrence of the perforation and indentation at the welding terminating end is due to a phenomenon in which molten metal flows in the direction opposite to the welding advancing direction, that is, flows backward in the scanning direction of the laser beam. Thus, as a result of extensive research, the present inventors have found that, when the scanning direction of the laser beam is reversed at the welding terminating end (at a geometric end of a bead to be formed as a welded joint) and then the laser scan is performed in the backward direction, newly produced molten metal flows to the side of the geometric end of the weld bead, and thereby the shortage of the molten metal at the geometric end is eliminated.
[0012] In this case, when the laser beam is irradiated again onto the metal portion brought into a molten state by the laser welding, the metal in the molten state is scattered, so that burn-through, and the like, is occurred. In contrast, in order to form new molten metal, the laser scan in the backward direction needs to be performed in a non-molten portion of the workpiece. However, the laser scan in the backward direction is performed in a non-molten portion of the workpiece by offsetting the laser beam from the weld bead formed by the laser scans in the forward direction, thereby, it is possible to supply the newly molten metal toward the geometric end of the weld bead, located rear side of the laser scan in the backward direction, without a problem such as burn-through.
[0013] Furthermore, when the laser scan is performed in the backward direction so as to allow a part of weld bead formed by the laser scan in the backward direction to overlap the weld bead formed by the laser scan in the forward direction, the flow of molten metal is promoted by the wettability of molten metal not only in the rear direction with respect to the scanning direction, but also in the side direction (the overlapping direction of the beads) with respect to the scanning direction. Thereby, the beads in the forward and backward directions can be fused together, and also, it is possible to avoid the shortage of molten metal at the time when the laser scan in the backward direction is terminated at a geometric intermediate position of the weld bead.
[0014] Furthermore, since the substantial welding length to the geometric end of the weld bead is secured, it is not necessary that, as in the conventional method, the welding length be shortened in order to prevent the perforation and indentation from being formed at the welding terminating end, and that the weld bead section be extended in order to avoid the shortening of the welding length. As a result, the increase in the required space for the weld bead can be minimized. Furthermore, the complicated focus control of the laser beam is not needed, and hence the burden on the welding equipment can also be reduced.
[0015] In the method according to the present invention, it is preferred that the scanning of the laser beam (Lb) in the backward direction be performed at a higher speed than the speed of the scanning of the laser beam in the forward direction.
[0016] When the laser scan in the backward direction is performed at a high speed, the energy supplied to the laser irradiation portion per unit time is reduced, as a result of which it is possible to obtain the same effect as that in the case in which the laser output is reduced. That is, the depth of the weld penetration by the laser scan in the backward direction is reduced, and hence the shortage of metal at the welding terminating end can be more effectively improved. Furthermore, when the laser scan in the backward direction is performed at a high speed, the time required for the laser scan in the backward direction is reduced, and hence the increase in the cycle time can be avoided. In addition, it is not necessary to perform the laser output control as well as the complicated focus control of the laser beam, and hence the burden on the welding equipment is further reduced.
[0017] Furthermore, in each of the above-described cases in which the method according to the present invention is used, a further preferred bead shape can be obtained by using the fade down procedure for reducing the laser output continuously or stepwise at the time of terminating the laser scan in the backward direction.
[0018] In the method according to the present invention, when the scanning the laser beam in the forward direction includes a curve-shaped laser scanning at least at the terminating end of the predetermined section, and in which the scanning of the laser beam in the backward direction is offset to the outer side in the curvature direction of the curve-shaped laser scanning. When the laser scan in the backward direction is performed by offsetting the laser beam to the outer side in the curvature direction, the metal of the non-molten portion can be fused with the already molten bead over a wider area and also the metallic vapor is preferably discharged, so that an excellent bead shape can be stably obtained.
[0019] On the other hand, when the scanning of the laser beam in the forward direction includes a curve-shaped laser scanning at least at the terminating end of the predetermined section, and in which the scanning of the laser beam in the backward direction is offset to the inner side in the curvature direction of the curve-shaped laser scanning, the conditions for obtaining a stable bead shape become severe to some extent as compared with the form in which the laser scan in the backward direction is performed by offsetting the laser beam to the outer side in the curvature direction of the curve-shaped laser scan. However, in the form in which the laser scan in the backward direction is performed by offsetting the laser beam to the inner side in the curvature direction of the curve-shaped laser scan, the weld bead formed by the laser scan in the backward direction is extended on the inner side of the bead shape, and hence this form is advantageous in that the required space of the weld bead is not increased.
[0020] As described above, in the laser lap welding method according to the present invention, complicated control, such as the focus control of a laser beam, is not needed, and hence the burden on the welding equipment is small. Furthermore, with the laser lap welding method according to the present invention, the perforation and indentation at the welding terminating end can be improved while an increase in the space and cycle time required to secure the welding length is avoided. Thus, the laser lap welding method according to the present invention is advantageous to improve the quality of laser lap welding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 includes FIG. 1(A) which is a plan view showing a laser scan in a laser lap welding method according to a first embodiment of the present invention, FIG. 1(B) which is a plan view showing a bead shape, FIG. 1(C) which is a graph showing a relationship between the laser output and the speed, and FIG. 1(D) which is a sectional side view of the bead;
[0022] FIG. 2 includes FIG. 2(A) which is a plan view showing a laser scan in a laser lap welding method according to a second embodiment of the present invention, and FIG. 2(B) which is a plan view showing a laser scan in a laser lap welding method according to a third embodiment of the present invention;
[0023] FIG. 3 includes FIG. 3(A) which is a plan view showing a transitional bead shape in the laser lap welding according to the second embodiment of the present invention, and FIG. 3(B) which is a cross-sectional view along the line B-B in FIG. 3(A) ;
[0024] FIG. 4 includes FIG. 4(A) which is a plan view showing a final bead shape in the laser lap welding according to the second embodiment of the present invention, and FIG. 4(B) which is a cross-sectional view along the line B-B in FIG. 4(A) ; and
[0025] FIG. 5 includes FIG. 5(A) which is a sectional side view showing a bead formed by a conventional laser lap welding method, FIG. 5(B) which is a plan view of the bead shape in the conventional laser lap welding method, FIG. 5(C) which is a graph showing a laser output, and FIG. 5(D) which is a sectional side view showing a bead formed by another conventional laser lap welding method.
DETAILED DESCRIPTION
[0026] In the following, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 includes FIG. 1(A) which is a plan view showing laser scans La and Lb performed in laser lap welding 10 according to a first embodiment of the present invention for lap welding two steel sheets 1 and 2 (galvanized steel sheets), FIG. 1(B) which is a plan view showing a bead shape, FIG. 1(C) which is a graph showing the laser output P and the speed V, and FIG. 1(D) which is a sectional side view of the bead.
[0027] FIG. 1 shows a case in which the laser lap welding is performed so as to eventually form a weld bead ( 10 ) having a linear shape. In this case, the two steel sheets 1 and 2 are overlapped via embossments (protrusions, not shown) formed in advance on one side (or both sides) of the steel plates, and thereby the two steel sheets 1 and 2 are held with jigs (not shown), such as clamps, in the state where a tiny gap g for discharging zinc vapor is formed between the two steel sheets 1 and 2 . Note that the gap g may be formed by spacers, or the like, instead of forming the embossments. Furthermore, in the case in which no galvanized layer exists on the joining surface of the two steel sheets 1 and 2 , or where the two steel sheets 1 and 2 are not provided with a layer plated with a low melting point metal, such as zinc, the two steel sheets 1 and 2 may be directly overlapped without forming the gap g.
[0028] The laser lap welding 10 is performed in such a manner that a weld bead 11 penetrating the two steel sheets 1 and 2 in the thickness direction is formed by starting the laser scan La in the forward direction from a starting end s and performing the laser scan in a linear manner at a constant laser output P and a constant scanning speed Va until the laser beam reaches an inversion portion t (geometric end), that the scanning direction is then inverted at the inversion portion t and, at the same time, the laser scan Lb in the backward direction is performed at the laser output P as it is and at a high scanning speed Vb so as to allow the laser beam to overlap a part of the weld bead 11 , and that the irradiation of the laser beam is terminated when the laser beam reaches a welding terminating end e.
[0029] As shown in FIG. 1(D) , at the starting end s of the weld bead 11 , the substantial welding length Wa starts from the point where the penetration formed by the laser irradiation from the above in the figure reaches the lower steel sheet 2 . On the other hand, at the inversion portion t, since the scanning direction is inverted in the state where the penetration (keyhole) formed by the laser irradiation penetrates the lower steel sheet 2 , and since molten metal flows into the inversion portion t (geometric end) located on the rear side in the advancing direction of the laser scan Lb in the backward direction which is performed after the inversion of the laser scan, the recessed portion shown in FIG. 1(D) and denoted by reference numeral 12 is buried (as will be described below), so that the substantial welding length Wa reaching a position very close to the geometric end (t) can be obtained.
[0030] The length of the laser scan Lb in the backward direction is not limited in particular, but the length of the laser scan Lb in the backward direction needs to be about four times or more of the width (Ba) of the weld bead 11 , and is preferably five times or more of the width (Ba) of the weld bead 11 . By the ratio of the length along the time axis T from the inversion portion t to the terminating end e in FIG. 1(C) with respect to the length from the inversion portion t to the terminating end e in FIG. 1(A) , FIG. 1(B) and FIG. 1(D) , it is shown that the time required for the section from the inversion portion t to the terminating end e is reduced in inverse proportion to the speed Vb.
[0031] Furthermore, as is clear from the example described below, the permissible range of the scanning speed Vb in the backward direction with respect to the scanning speed Va (welding speed) in the forward direction relates to a shift between the laser scan La in the forward direction and the laser scan Lb in the backward direction, that is, an offset D ( FIG. 3 and FIG. 4 ). When the offset D is set to an optimum value, the laser scan can be performed at a multiple speed ratio of Vb/Va=1, that is, a constant speed. However, in this case, the final bead width at the inversion portion t (geometric end) is slightly increased. When the multiple speed ratio Vb/Va is two or less, and when the offset D is small, the remelting rate of the metal of the molten portion is increased, so that a hole defect is not left in the inversion portion t (geometric end) but is left in the vicinity of the terminating end e of the laser irradiation.
[0032] As the multiple speed ratio Vb/Va is increased, the reducing effect of the laser output (power density) due to the increase in the scanning speed is exhibited, and the permissible range of the offset D is increased on the side of reducing the offset D. When the multiple speed ratio Vb/Va is set to two to three, the permissible range of offset D is maximized. When the multiple speed ratio Vb/Va is set to four or more, the power density becomes insufficient, and the permissible range of the offset D is reduced. However, the cycle time is reduced by the amount of time corresponding to the increase in the laser scanning speed.
[0033] Next, FIG. 2(A) shows a laser scan in laser lap welding 20 according to a second embodiment of the present invention, and FIG. 2(B) shows a laser scan in laser lap welding 30 according to a third embodiment of the present invention. Any of the second and third embodiments shows an embodiment which forms a circular weld bead having an opened portion, and which is particularly suitable for laser welding (unit welding) as an alternative to spot welding in an automotive vehicle body welding process.
[0034] Among the second and third embodiments, in the laser lap welding 20 according to the second embodiment shown in FIG. 2(A) , after the laser scan La in the forward direction is performed circularly from the starting end s to the inversion portion t (the geometric end of the weld bead), the scanning direction is reversed at the inversion portion t, and then the laser scan Lb in the backward direction is performed to the terminating end e by offsetting the laser beam to the outer side of the circular arc (on the outer side in the curvature direction). On the other hand, in the laser lap welding 30 according to the third embodiment shown in FIG. 2(B) , the laser scan La in the forward direction is performed from starting end s to the inversion portion t similarly to the second embodiment, but the third embodiment is different in that the scanning direction is reversed at the inversion portion t, and then the laser scan Lb in the backward direction is performed to the terminating end e by offsetting the laser beam to the inner side of the circular arc (on the inner side in the curvature direction).
[0035] As described above, the gap g is formed between the two galvanized steel sheets 1 and 2 in order to discharge the zinc vapor generated at the time of welding the galvanized steel sheets 1 and 2 . However, in the case of the weld beads 20 and 30 having a circular shape as in the second and third embodiments, when the welding is performed to reach the inversion portion t (the geometric end) and to again approach the starting end s, the inside of the weld beads 20 and 30 is in the state of communicating with the outside air only through the discontinuous portion between the starting end s and the inversion portion t. Thus, the weld bead 20 according to the second embodiment in which the scanning direction is reversed by offsetting the laser beam to the outer side of the circular arc is advantageous from the viewpoint of discharging the zinc vapor.
[0036] FIG. 3 shows a transitional bead shape in the laser lap welding 20 according to the second embodiment, and FIG. 4 shows a final bead shape. In the state where a weld bead 21 is formed from the starting end s to the inversion portion t by performing the laser scan La in the forward direction from the starting end s to the inversion portion t, a recessed portion (a portion of insufficient molten metal) corresponding to the thickness of the upper steel sheet 1 is caused momentarily as shown in FIG. 3(B) . In this state, the scanning direction of the laser is reversed, and then the laser scan Lb in the backward direction is performed by offsetting the position of the laser beam from the position of the laser beam in the laser scan La in the forward direction. Thereby, a non-molten portion of the steel sheet 1 along the outer peripheral side of the weld bead 21 is melted and flows into the recessed portion of the weld bead 21 , which portion is still in a molten state. As a result, the recessed portion is made to be shallow and flattened as shown in FIG. 4(B) .
[0037] The laser scan Lb in the backward direction is performed at a high speed, similarly to the first embodiment. Thus, even when the laser output and the spot diameter in the laser scan Lb in the backward direction are the same as the laser output and the spot diameter in the laser scan La in the forward direction, the reducing effect of the laser output (power density) is obtained. Thereby, the bead width Bb in the laser scan Lb in the backward direction is made narrower than the bead width Ba in the laser scan La in the forward direction and, at the same time, the depth of the penetration is reduced to be less than the thickness of the upper steel sheet 1 . When this state is reached, defects, such as an indentation, are not left even by terminating the laser scan Lb in the backward direction at the terminating end e.
Examples
[0038] In order to verify the effect of the laser lap welding method according to the present invention, experiments were performed in the laser lap welding 20 and 30 according to the second and third embodiments described above, and the quality of the weld bead was evaluated in each of the cases in which the offset D between the laser scan La in the forward direction and the laser scan Lb in the backward direction, and the scanning speed Vb of the laser scan Lb in the backward direction were changed.
[0039] In the experiments, an optical fiber laser oscillator (having a maximum output: 7 kW, the diameter of transmission fiber: 0.2 mm) manufactured by IPG photonics company, and a scanner head (processing focal diameter in the focused state: 0.6 mm) manufactured by HIGHYAG laser technology company were used. In each of the states where a non-plated steel sheet ( 1 ) having a thickness of 0.65 mm was overlapped on a galvanized steel sheet ( 2 ) having a thickness of 0.8 mm with gaps g=0.1 and 0.2 mm so as to be used as workpieces (a part of the experiments were performed in the case of the gap of 0.05 mm), when the circular laser scan La in the forward direction was performed under the conditions of the laser output: 4.3 kW, the laser beam diameter: 7 mm, the length of the discontinuous portion: 1 mm, the set welding length: 21 mm, the scanning speed: Va=6.9 m/min (first half) to 7.2 m/min (second half), and when the laser scan Lb in the backward direction was performed over one fourth (6.3 mm) of the circumference length in such a manner that the laser beam was offset to the outer peripheral side, that the scanning speed was changed from Vb=7.2 m/min (constant speed) to 35 m/min (4.8-fold speed, partially Vb=75 m/min (10.4-fold speed), and that the offset D was changed between D=0.1 mm and D=1.2 mm in steps of 0.1 mm, the depth of indentation between the inversion portion t and the terminating end e of the weld bead was measured, and the appearance on each side of the front and back surfaces of the pair of steel sheets were observed. The results of the experiments are shown in Table 1.
[0000]
TABLE 1
Offset D (mm)
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
Scanning speed Vb
7.2
X
X
⊚
(m/min)
10
X
X
X
X
⊚
⊚
15
Δ
Δ
⊚
⊚
⊚
⊚
⊚
20
X
Δ
◯
◯
◯
◯
⊚
⊚
◯
⊚
⊚
⊚
⊚
25
◯
◯
⊚
◯
◯
⊚
⊚
⊚
30
◯
◯
◯
◯
⊚
⊚
⊚
35
◯
◯
⊚
⊚
⊚
⊚
40
Δ
◯
⊚
45
⊚
50
◯
⊚
[0040] In Table 1, the case in which the indentation depth was less than 0.4 mm is represented by a “double circle”, the case in which the indentation depth was 0.4 mm or more and less than 0.5 mm is represented by a “circle”, the case in which the indentation depth was 0.5 mm or more and less than 0.65 is represented by a “triangle”, and the case in which the indentation depth was 0.65 mm or more, or a hole penetrating the upper steel sheet 1 was confirmed is represented by a “cross”.
[0041] As shown in Table 1, it was confirmed that, when the scanning speed Vb in the backward direction is set to a value of two times or more (15 m/min or more) of the scanning speed Va (7.2 m/min) in the forward direction, welding can be performed with stable quality in a relatively wide range of offsets D (the shift between the laser scan La in the forward direction and the laser scan Lb in the backward direction), which range corresponds to 15 to 95% of the beat width Ba (about 1.2 mm).
[0042] Furthermore, it was confirmed that, in the case of the offset D=0.7 mm which corresponds to about 60% of the bead width Ba and which is close to an optimum value of the offset D, neither an indentation nor a hole defect is caused even when the scanning speed Vb in the backward direction is set to a high speed. Table 1 shows the results of experiments in which the scanning speed Vb is 50 m/min or less, but good results were obtained in the range of the scanning speed Vb of 75 m/min or less.
[0043] Furthermore, in the case in which the offset D was set to 0.8 mm, no indentation was caused even when the scanning speed Vb in the backward direction was equal to the scanning speed Va (welding speed) in the forward direction. However, in this case, the bead width at the bead end was slightly increased. Thus, it can be said that, when the scanning speed Vb in the backward direction is equal to or set to a lower multiple of the scanning speed Va in the forward direction, it is advantageous to use the laser output control together with the above-described laser scanning control.
[0044] The above-described experiments relate to the case in which the laser scan Lb in the backward direction was performed by offsetting the laser beam to the outer peripheral side from the circular laser scan La in the forward direction. However, when similar experiments were also performed in the case in which the laser scan Lb in the backward direction was performed by offsetting the laser beam to the inner peripheral side from the circular laser scan La in the forward direction, generally the same tendency was confirmed, although the suitable offset range was slightly reduced as compared with the case in which the laser scan Lb in the backward direction was performed by offsetting the laser beam to the outer peripheral side from the circular laser scan La in the forward direction. However, in the case in which the laser scan Lb in the backward direction was performed by offsetting the laser beam to the inner peripheral side from the circular laser scan La in the forward direction, so as to reduce the radius of the bead, the laser scan Lb in the backward direction was performed over three eighths of the circumference length (7 mm) so that approximately the same scanning distance could be obtained.
[0045] Differences in the experimental results between in the case of the offset to the inner peripheral side and in the case of the offset to the outer peripheral side were seen when the gap was small (0.1 mm and 0.05 mm) causing a blow hole, a burn-through, and the like. This is considered to be due to the fact that, when the gap between the steel sheets is small, and when the laser scan Lb in the backward direction is performed on the inner peripheral side of the circular bead, the discharge property of the metallic vapor is deteriorated. However, in the case of the smallest gap g of 0.05 mm, no burn-through was caused, and generally better results were obtained as compared with the results in the case of the gap g of 0.1 mm. This is considered to be due to the fact that, when the gap g is smaller, the amount of molten metal entering into the gap g is smaller. It is, of course, considered that, when non-plating steel sheets, between which the gap g need not be provided, are used, the ranges of the suitable offsets D and of the scanning speed Lb can be further increased.
[0046] In the above, some embodiments according to the present invention have been described, but the present invention is not limited to the above described embodiments, and various modifications and changes can be made on the basis of the technical concept of the present invention.
[0047] For example, the case in which two steel sheets are overlapped and laser-welded is shown in the above-described embodiments. However, the laser lap welding method according to the present invention can also be applied to the workpiece having the other form, and can also be applied to the case in which three or more steel sheets are overlapped and laser-welded. Furthermore, the cases in which the weld bead has a linear shape and a circular shape (circular arc shape) are shown in the above-described embodiments, but the laser lap welding method according to the present invention can be applied to any shape of the weld beam other than these shapes of the weld bead.
[0048] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.
|
A laser lap welding method by irradiating of a laser beam from one side of a plurality of overlapped workpieces ( 1, 2 ), the method includes the steps of: scanning (La) the laser beam in the forward direction along a predetermined section of the workpieces; reversing the scanning direction of the laser beam at a terminating end (t) of the predetermined section; scanning (Lb) the laser beam in the backward direction and terminating of the irradiating of the laser beam onto the predetermined section, wherein the scanning of the laser beam in the backward direction is offset from the scanning of the laser beam in the forward direction such that a part of weld bead ( 12 ) formed by the laser scanning in the backward direction overlaps the weld bead ( 11 ) formed by the laser scan in the forward direction.
| 1
|
BACKGROUND OF THE INVENTION
This invention relates to a hydraulic needle bar positioning apparatus for a multiple needle tufting machine, and more particularly to a computer control system for a hydraulic needle bar positioning apparatus for a multiple needle tufting machine.
Heretofore in the production of tufted fabrics, distinctive patterns, such as various zig-zag patterns have been formed in backing fabrics by transversely or laterally shifting the needle bar, or by shifting the backing material support beneath the needles, needle-gauge increments for each stitch, in accordance with a predetermined pattern.
One means for executing this lateral or transverse shifting of the needle bar, or the backing material support, is a pattern cam continuously rotated in synchronism with the rotary drive of the tufting machine, in which the pattern cam engages a movable needle bar, or a laterally reciprocably movable backing material support. Examples of such pattern cam control mechanisms for laterally shiftable needle bars or fabric supports are disclosed in numerous prior U.S. patents, such as the following:
______________________________________2,513,261 Behrens June 27, 19502,679,218 Jones May 25, 19542,682,841 McCutchen July 6, 19542,855,879 Manning et al Oct. 14, 19583,026,830 Bryant et al Mar. 27, 19623,100,465 Broaderick Aug. 13, 19633,109,395 Batty et al Nov. 5, 19633,396,687 Nowicki Aug. 13, 1968______________________________________
There are numerous disadvantages in the use of pattern cams for controlling the lateral or transverse shifting of needle bars or fabric supports.
Since the pattern cam control mechanism is entirely mechanical, there is considerable wear on both the cam surfaces and the cam rollers or followers.
There is a long change-over period for the pattern cams, when patterns of different designs are required.
Machine speed is limited by, not only the mechanical arrangement, but also the abrupt changes in the pattern cam surfaces.
There is extremely high machine stress caused by having no accelerate the lateral movement of the needle bar to near infinity because of the sharp cam lobes.
Where there are machining inaccuracies in the profile of the cams, differing lateral or transverse relationships between the hooks and needles may be produced for different pattern positions.
The continuous operation of the pattern cams and cam followers produces an excessive noise level.
The common assignee's prior U.S. Pat. No. 4,173,192 discloses an electrohydraulic needle bar positioning apparatus including a hydraulic actuator coupled to the needle bar and controlled by an electronic control circuit including a PROM (Programmable Read Only Memory) for deter mining the stitch pattern of the tufting machine.
Although the electrohydraulic needle bar positioner of the prior U.S. Pat. No. 4,173,192, overcame many of the disadvantages of a cam-controlled needle bar positioner or shifter, nevertheless, the electronic controls for the previous electrohydraulic needle bar positioner produced an instantaneous command change to the hydraulic actuator calling for instantaneous maximum speed of the transversely moving needle bar independent of the tufting machine's main motor speed. Such abrupt speed changes caused excessive shock loads to the machinery which in turn limited the machine life.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide improved controls for a hydraulic actuator for a needle bar positioning apparatus for a multiple needle tufting machine, will minimize the abrupt transverse movements of the needle bar and substantially reduce the shock loads imparted to the tufting machine.
Another object of this invention is to provide an electronic computer control system for synchronizing the needle bar positioning closely with the main shaft speed or stitch rate of the tufting machine in order to reduce the shock load on the machine.
Another object of this invention is to provide a computer control system for an electrohydraulic needle bar positioning apparatus which will gradually increase the velocity of the transversely moving needle bar at the commencement of the needle bar movement and gradually decrease the velocity of the needle bar at the termination of the needle bar movement.
The electrohydraulic positioning apparatus includes a hydraulic actuator coupled to the needle bar for transversely shifting or positioning the needle bar. The actuator is provided with a feedback transducer for monitoring the transverse position of the actuator at any current time. Both the actuator and the transducer are in electrical communication with a computer control unit, preferably in the form of a microprocessor. The microprocessor also receives input signals from an encoder which generates a plurality of encoder counts or signals for each revolution of the main shaft of the tufting machine, and hence for each stitch of the needles. The microprocessor control unit is programmed to produce a desired stitch pattern in which the needle bar is shifted in needle-gauge increments transversely in either direction and only while the needles are above the backing fabric. Moreover, the programmed pattern information within the microprocessor produces a position command signal, which changes linearly with the encoder counts only during that portion of the stitch cycle in which the needles are above the backing fabric. Moreover, the pattern command signals are generated to accommodate the inertia of the rapidly and transversely reciprocating needle bar as the needle bar moves from one needle gauge stitch position to another. Specifically, the command signal to shift the needle bar commences slightly before the needles rise out of the backing fabric or material and terminates before the needles re-enter or penetrate the backing fabric.
The microprocessor control unit is also designed to compare digital position command signals with digital information from feedback signals generated by the feedback transducer on the hydraulic actuator corresponding to the current position of the actuator, in order to produce a resultant drive signal which energizes the servovalve of the hydraulic actuator.
The electrohydraulic needle bar positioning apparatus made in accordance with this invention has practically no wearing parts and is therefore capable of substantially longer life and longer continual operational time than the prior art cam-controlled positioning devices.
The stitch patterns may be introduced into the microprocessor by manual I/O operator terminals, or by PROMS, similar to those utilized in the positioning apparatus disclosed in the above U.S. Pat. No. 4,173,192.
The positioning apparatus made in accordance with this invention provides accurate needle positioning information without the necessity of accurate machining of mechanical parts, and also permits repeat patterns having a substantially greater number of stitches than in prior needle bar shifting apparatus and particularly in those which are cam-controlled.
This positioning apparatus is a "closed loop system" which provides constant feedback information designating the exact position of the needles at all times, for greater control of the needle bar shifting movements.
Greater operating speeds of the tufting machine at low noise levels and with a minimum of abrupt shocks to the machine are possible with the positioning apparatus incorporating the computer control system of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective schematic view of a multiple-needle tufting machine incorporating the electrohydraulic needle bar positioning apparatus of this invention;
FIG. 2 is an enlarged, fragmentary sectional elevation of a needle and looper forming cut pile stitching in the base fabric of FIG. 1;
FIG. 3 is a schematic block diagram of the needle bar positioning apparatus of FIG. 1;
FIG. 4 an enlarged section taken along the line 4--4 of FIG. 3;
FIG. 5 is a block diagram of the microprocessor based controller disclosed in FIG. 3;
FIG. 6 is a graph of the linear relationship between the position command signals and the encoder counts generated by the control system for movement of the needle bar between first and second positions;
FIG. 7 is a graph similar to that of FIG. 6, but illustrating the position command signal and encoder count relationship for shifting movement of the needle bar between the second position and the first position;
FIG. 8 is a graph similar to that of FIG. 6, illustrating the position command signal and encoder count relationship for shifting movement of the needle bar between a first and a third position, that is through a multiple gauge interval; and
FIG. 9 is a graph similar to that of FIG. 6, illustrating the relationship between the position command signal and the encoder count for the prior art electrohydraulic needle bar positioner, disclosed in prior U.S. Pat. No. 4,173,192.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Since multiple-needle tufting machines are so well-known in the art, only the basic elements of a typical multiple-needle tufting machine have been disclosed schematically in FIG. 1.
The tufting machine 10 disclosed in FIG. 1 includes a rotary needle shaft or main shaft 11 driven by a stitch drive mechanism 12 from a drive motor 13. Rotary eccentric mechanisms 15 mounted upon the rotary needle shaft 11 are adapted to reciprocably move the vertical push rods 16 for vertically and reciprocably moving the needle bar slide holder 17 and the needle bar 18. The needle bar 18 supports a plurality of uniformly spaced tufting needles 20 in a longitudinal row, or staggered longitudinal rows, extending transversely of the feeding direction 21 of the backing fabric or material 22.
The backing fabric 22 is moved longitudinally through the tufting machine 10 by the backing fabric feed mechanism 23 and across a backing fabric support, including the needle plate 24 (FIG. 2).
Yarns 25 are fed from the yarn supply 26 to the respective needles 20. As each needle 20 carries a yarn 25 through the backing fabric 22, a hook 27 is reciprocably driven by the looper drive 29 to cross each corresponding needle 20 and hold the corresponding yarn 25 to form the loops 30 (FIG. 2). The cut pile tufts 31 are formed by cutting the loops 30 with each knife 28.
Of course, by eliminating the knives 28 and by reversing the direction of, and substituting, loop hooks for the cut pile hooks 27, uncut loops 30 may be formed instead of the cut pile tufts 31, as disclosed in FIG. 2, in a well-known manner.
The needle bar positioning apparatus 32 is designed to laterally or transversely shift the needle bar 18 relative to the needle bar holder 17 a predetermined transverse distance equal to the needle gauge, or a multiple of the needle gauge, and in either transverse direction from its normal central position, relative to the backing fabric 22, and for each stitch of the needles 20.
In order to generate input encoder signals for the needle bar positioning apparatus 32 corresponding to each stitch of the needles 20, an encoder 34 is mounted upon a stub shaft 35, which is operatively connected by coupling 36 to the main shaft or needle shaft 11, so that the stub shaft 35 will have the same RPM s as the needle shaft 11. Since the needle shaft 11 makes one revolution per stitch, the stub shaft 35 will also make one revolution per stitch.
FIG. 3 is a schematic block diagram of the needle bar positioning apparatus 32, the encoder 34, the operator interface device which is an operator I/O (input/output) terminal 38, as well as an optional yarn feed clutch mechanism 40 forming a part of the yarn supply 26. The needle bar positioning apparatus 32 includes a hydraulic actuator 42 adapted to be controlled by the microprocessor based controller 43. The hydraulic actuator 42 is coupled to the needle bar 18 for lateral shifting relative to the tufting machine 10.
The linear hydraulic actuator 42 may be substantially the same as that disclosed in the prior U.S. Pat. No. 4,173,192, and includes an elongated hydraulic cylinder 44 enclosing a linearly reciprocable piston or actuator rod 45 carrying the piston 46 for movement linearly within the hydraulic chamber 47 and connected through coupling 48 to the needle bar 18, as best illustrated in FIG. 3. Hydraulic fluid is supplied to the piston chamber 47 from a pump and pump controls 50 through fluid line 51, servovalves 52, and manifold 49, alternately through the cylinder ports 53 for controlling transverse linear movement of the piston 46 and actuator rod 45, and consequently the needle bar 18.
Attached to the opposite end of the hydraulic cylinder 44 from the needle bar 18 is a feedback transducer 54 adapted to cooperate with the transversely shifting piston rod 45 to produce feedback signals to the microprocessor based controller 43 corresponding to the actual position of the actuator rod 45 and hence the needle bar 18. The particular position feedback transducer 54 used is a "Temposonics" magnetostrictive-type position transducer, Part No. DCTM-402-1. Although the transducer mechanism disclosed in the prior U.S Pat. No. 4,173,192 may be utilized, nevertheless, the above-described "Temposonics" position transducer improves the linearity performance of the feedback transducer 54.
Although the servovalve disclosed in the prior U.S. Pat. No. 4,173,192 may be utilized, nevertheless, it is preferred that two such servovalves be used, as illustrated in FIG. 3 in order to improve the maximum rate of shifting of the actuator or piston rod 45 and the needle bar 18.
The servovalve 52 is connected through electrical bus 55 to the microprocessor controller 43, while the transducer 54 is coupled to the controller 43 through the electrical bus 56.
The encoder 34 utilized in this invention is preferably a quadrature phase incremental encoder with index impulse (DISC. INSTRUMENTS, Part No. 702 FR-1000-IBF-5-LD). As illustrated in FIGS. 3 and 4, the encoder 34 includes a transparent shutter disk 57 fixed upon the stub shaft 35 for rotation between a lamp 58 and a photoelectric cell 59, in order to intercept a light beam 60 passing through the shutter disk 57 adjacent its periphery. As best illustrated in FIG. 4, formed upon the shutter disk 57 are a plurality of uniformly and circumferentially spaced opaque lines 61, each line 61 being adapted to break the light beam 60 as it crosses the light beam 60 during the rotational movement of the disk 57. In a preferred form of the invention, there are 1,000 radial opaque lines 61 impressed upon the disk 60. Thus, each time the disk 57 completes one revolution, the light beam 60 will have been broken 1,000 times to produce 1,000 encoder signals per revolution of the main shaft 11. Each interruption of the light beam 60 is converted by the photocell 59 into an electrical input or encoder signal which is transmitted by the lead 62 to the microprocessor based controller 43.
The operator I/O terminal 38 (FIG. 3) may be a "Fluke, Model 1021" operator terminal, and functions as a means for introducing data into the microprocessor based controller 43 through bus 64, which may be the industry standard "RS232 Serial Communication Line".
The block diagram of FIG. 5 illustrates the various components of the microprocessor based controller 43. Basically, the controller 43 includes a computer processing unit 65, a signal processing unit 66, and a power supply and machine interface 67. The computer processing unit 65 functions as a computational and logic execution element only. All information utilized by this unit 65 is digitally encoded into 8 bit bytes or 16 bit words. All real world signals are conditioned on the signal processing unit 66 which converts such signals from analog levels into digitally encoded information usable by the computer processing unit 65.
The power supply and machine interface 67 provide appropriate power to the electronic elements within the computer processing unit 65 and the signal processing unit 66, utilizing standard 120 VAC power available as the input. Conditioned power is generated by a Power General (Part No. DC50-2A) power supply. The machine's discrete interfaces are made through commercially available electromechanical relays and optical isolaters.
As disclosed in FIG. 5, the computer processing unit 65 includes a central processing unit (CPU) 68, specifically a Motorola Part No. MC68000, microprocessor integrated circuit. The central processing unit 68 performs all computational and logic operations along with generating the required system bus 69 functions of address, data and control. All devices in the microprocessor based controller 43 are synchronized by the clock 70 which is a crystal oscillator manufactured by Fox (Part No. F1100). The speed of the system clock 70 is 10 megahertz.
The control algorithm or algorithms are stored in the system ROM or PROM (programmable read only memory) 71. The integrated circuits incorporated in the PROM 71 are those of Signetics Corp., Part No. 27C256-15FA.
The parallel I/O controller and timer integrated circuit 73 is preferably Mostek, Part No. MK68230N 10, and provides logic level interface to the system as well as generating critical internal timing markers for the system.
The buffer storage memory RAM (random access memory) 74 is preferably Toshiba Part No. TC5565APL. The RAM 74 serves as the storage location for all dynamic control variables, particularly those which change at very high speed, such as encoder counts and the command and feedback position signals, to be discussed later.
The serial communication bus 64 from the operator I/O terminal 38 communicates with the system bus 69 through the DUART (dual universal asynchronous receiver transmitter) 75, preferably a Motorola integrated circuit, Part No. MC68681.
As illustrated in FIG. 5, the computer processing unit 65 communicates with the signal processing unit 66 through the system bus 69.
As further illustrated in FIG. 5, the feedback transducer 54 is connected through bus 56, transducer interface 76, and bus 77 to the A/D (analog-to-digital) converter 78, which converts the DC feedback voltages into corresponding digital information which is transmitted through the system bus 69 to the computer processing unit 65. The A/D converter 78 may be National Part No. AD574AJD, for processing an analog feedback signal of plus or minus 10 volts D.C. proportional to the actuator position.
The system bus 69 also communicates with the D/A (digital-to-analog) converter 80 for converting the output digital signals or information into a corresponding analog drive signal i the form of a DC voltage, which is then amplified in the servovalve drive circuit 81. The amplified analog drive signal is then transmitted through the bus 55 to energize the servovalve 52 to open the flow of hydraulic fluid to the hydraulic actuator 42 in an amount and direction proportional to the magnitude and polarity of the drive signal. The D/A converter 80 may be a National D to A converter IC, Part No. DAC1209LCJ.
Also connected to the system bus 69 is the encoder interface 82 consisting of the logic circuitry required to count the output pulses from the incremental encoder 34. The encoder interface logic circuitry 82 may be National 74HC193 up/down counters.
Also connected to the system bus 69 is a remote data storage interface 84 serving to provide the system with preprogrammed pattern information. The interface 82 is usually in the form of a plug-in prom, similar in function to that disclosed in FIG. 4 of U.S. Pat. No. 4,173,192. Differently programmed PROMS or interfaces 84 may be used for different patterns to be formed in the backing fabric 22. This interface 84 is provided to prevent external noise or interference from corrupting the system bus 69 and is preferably National 74HCT245 tri-state latches.
Instead of introducing different pattern information through the interface 84, it may be introduced through the operator I/O terminal 38 where such information is stored in the PROM 71. The operator I/O terminal 38 may also be used to enter calibration data information relating to the particular tufting machine 10. The terminal 38 may also be used to display error signals for monitoring and correction, as well as production statistics for a particular machine 10.
FIG. 6 graphically illustrates the algorithm utilized in the microprocessor based controller 43 for controlling the transverse shifting movement of the needle bar actuator 42.
When the machine 10 is in operation, the microprocessor based controller 43 receives continuously encoder signals at the rate of 1,000 per revolution, as illustrated by the X-axis of the graph disclosed in FIG. 6. The encoder signals are read and decoded by the controller 43 and used by the controller 43 to compute the ramped command signal illustrated by the graph in FIG. 6.
The algorithm incorporated in the controller 43 defines a relationship between the encoder counts on the X-axis and certain position command signals on the Y-axis corresponding to desired transverse positions of the needle bar 18, represented by the graphs displayed in FIGS. 6, 7 and 8. The encoder 34 is set so that after a predetermined number of encoder counts, such as at the out-of-backing encoder count 86 having a value, such as 340 counts, the needles 20 have been elevated by the needle bar 18 to a position in which the tips of the needles have just cleared the backing fabric 22. As the encoder 34 continues to count, and reaches the encoder count 87 having a value of, for example, 590 counts, as illustrated in the graph in FIG. 6, the descending needles 22 are just entering the backing fabric 22.
The horizontal line 88 represents the constant value of the digital position command signal when the needle bar 18 is in a transverse stationary position 1 in which the needle bar 18 is not shifting, and preferably when it is in its normal central position. Moreover, the length of the horizontal line 88 corresponds with a number of encoder counts in the stitch cycle in which the needles 20 are penetrating the backing fabric 22, and no drive signal to the servovalve 52 is generated.
The horizontal line 89 represents another constant value of the digital position command signal when the needle bar 18 is in another transverse stationary position 2 in which the needle bar 18 is not shifting, but has been transversely shifted one needle gauge from position 1. Moreover, the length of the horizontal line 89 corresponds with a number of encoder counts in the stitch cycle in which the needles 20 are penetrating the backing fabric 22, and no drive signal to the servovalve 52 is generated.
A linear sloping ramp line 90 connects the two horizontal position lines 88 and 89, preferably at points corresponding to encoder counts 91 and 92, defining a slope of less than 90 deg. The sloping ramp line 90 corresponds to a number or span of encoder counts during the stitch cycle, in which a command signal is generated, which after being compared with a current feedback signal from the feedback transducer 54, will produce a drive signal which will cause the actuator to shift the needle bar 18 from transverse position 1 to transverse position 2. The difference between the initial encoder count 91 of the ramp 90, later referred to as the early shift count, and the final or terminal encoder count 92 of the ramp 90 is referred to as the "Positioning Window" (PW), (FIG. 6).
The difference between the out-of-backing encoder count 86 and the in backing encoder count 87 is referred to as the "Shifting Window" (SW), and represents the number of encoder counts, or the rotary angle of the main shaft 11, during which the needles 20 are elevated and not penetrating the backing fabric 22, and during which the needle bar 18 may be transversely shifted in either direction.
As further illustrated in FIG. 6, the early shift count 91 is represented on the X-axis by a value, such as 310 encoder counts, slightly in advance of the out-of-backing encoder count 86, which is represented by a value, such as 340 counts. When the encoder 34 counts to the early shift count 91, the resulting signal is processed by the signal processing unit 66 and transmitted to the CPU 68 to generate the position command signals represented by the ramp line 90 disclosed in FIG. 6, until the encoder count 92 is reached and the constant command signal represented by the horizontal line 89 is generated to de-energize the servovalve 52.
It will be noted in FIG. 6, that the encoder count 92 having a value, such as 540 counts, occurs a predetermined number of counts in advance of the in-backing encoder count 87 having a value, such as 590 encoder counts, in order to define the cushion interval 93, having a value, in this instance, of 50 encoder counts.
Because of the substantial speeds, such as 1,250 RPM of the main shaft 11 of the tufting machine 10, and because of the inertia of the hardware, such as the servovalve 52 and the transversely moving parts of the machine, including the needle bar 18 and the actuator rod 48, the early shift count 91 and the cushion interval 93 are provided for in the algorithm of the microprocessor controller 43.
Thus, as illustrated in FIG. 6, the initial position command signal generated at the early shift count 91, slightly in advance of the out-of-backing encoder count 86, commences the sequence of digital operations within the controller 43 which subsequently commences the shifting of the actuator bar 45, after the inertia of the transversely moving hardware has been overcome. Thus, by the time the actuator rod 45 and the needle bar 18 actually commence their transverse shifting movement at the beginning of the "Shifting Window" (FIG. 6), the needles 20 will have risen out of the backing material 22 at, or just after, the encoder count 86.
Also, because of the inertia of the transversely moving hardware, including the needle bar 18 and the actuator rod 45, the position command signal is terminated at the encoder count 92 to permit the transversely moving hardware to coast or slow down before it stops just prior to the introduction of the descending needles 20 into the backing material 22 at, or just prior to, the encoder count 87.
Although the generation of position command signals at the early shift count 91, and for the "Shifting Window" (SW) are dependent upon the angular position of the main shaft 11, or the number of encoder counts, the cushion interval 93 is solely time dependent. Stated another way, regardless of the rotary speed of the main drive shaft 11, the values of the encoder counts in the graph of FIG. 6 remain the same, except for the length of the cushion interval 93. Although the position command signals for positions 1 and 2 will remain the same, the slope of the ramp 90 will vary with the length of the cushion interval 93. When the cushion interval 93 increases, the slope of the ramp 90 will increase. Since the cushion interval 93 is time dependent, the length of the cushion interval 93 will remain constant only as long as the speed of the main drive shaft 11 is constant. When the speed of the main drive shaft 11 is low, for example 200 RPM, the cushion interval 93 will be substantially shorter, that is, there will be less of a difference between encoder counts 92 and 87, because it is not necessary to provide much of a cushion when the machine is operating at lower speeds. Moreover, the slope of the ramp command 90 will decrease. On the other hand, at substantially higher speeds, the length of the cushion interval 93, that is the number of encoder counts, will increase proportionally to the machine speed, or speed of the main shaft 11, while the slope of the ramp command increases.
The following definitions and relationships are incorporated in the algorithm programmed into the microprocessor based controller 43.
__________________________________________________________________________ELEMENT UNITS__________________________________________________________________________POSITIONING WINDOW (PW)- encoder countsIN-BACKING COUNT (IB)- encoder countsOUT-OF-BACKING COUNT (OB) - encoder countsMACHINE SPEED (V) - encoder counts millisecondsNEXT STEP OR POSITION (NP) (e.g. position commandPOSITION 2) - counts (Y-axis)PREVIOUS STEP OR POSITION (PP) (e.g. position commandPOSITION 1) - counts (Y-axis)RAMP COMMAND (RC) - position command countsDELTA ENCODER POSITION (DELTA EP) - encoder countsRAMP SLOPE (RS) - position command counts/encoder countsCUSHION INTERVAL (CI) - millisecondsCURRENT ENCODER POSITION (CURRENT encoder countsEP) -EARLY SHIFT COUNTS (ES) - encoder countsCOMPUTATIONSPOSITIONING WINDOW (PW) = [IB - ES] - [V × CI] ##STR1##__________________________________________________________________________
The above computations are executed by the microprocessor based controller 43 once for each revolution of the main shaft 11, and prior to the early shift count (ES).
At each update of the controller 43, that is 2000 times per second, and independently of the main shaft RPM's or machine speed (V), the following equations are computed:
DELTA ENCODER POSITION (DELTA EP)=CURRENT EP-ES RAMP COMMAND (RC)=PP+(DELTA EP×RS)
The algorithm incorporating the above relationships is programmed into the software and is resident in the system ROM or PROM 71. The actual position commands or pattern information are stored on PROMS, such as the plug-in PROM or interface 84 (FIG. 5), similar to the PROM disclosed in the prior U.S. Pat. No. 4,173,192, or are entered as data through the operator I/O terminal 38.
It will be noted in FIG. 6 that the interval between the position command signals for positions 1 and 2 must be commensurate with the needle gauge since the needle bar 18 must be stopped in a transverse position precisely so that each needle 20 may cooperate with its corresponding looper or hook 27 and/or knife 28, (FIG. 2).
FIG. 7 is a graph similar to FIG. 6, but illustrating graphically the relationships between the position command signals and the encoder counts for the reverse movement of the actuator 42 and the needle bar 18, that is where the needle bar 18 is being moved from position 2 back to position 1. The linear ramp command 95 is the reverse or mirror image of the ramp command 90 of FIG. 6. Here again, the early shift count 91 is in advance of the out-of-backing encoder count 86, and the termination of the command signal at the end of the positioning window at the encoder count 92 is also in advance of the in-backing encoder count 87 to provide the cushion interval 93 in advance of the in-backing encoder count 87.
FIG. 8 is a graphical illustration similar to that in FIG. 6 of the relationships between the position command signals and the encoder counts utilized to shift the needle bar from position 1 to position 3 for each revolution of the main drive shaft 11. It will be noted in FIG. 8 that the differences in the critical encoder counts 91, 86, 92, and 87 are identical to those in FIG. 1, since the needles 20 rise out of the backing fabric 22 and enter the backing fabric 22 during the same angular intervals of each revolution of the main shaft 11, while the needle bar 18 must be shifted twice as far, that is through an interval of two needle gauges. The position command signals for Position 1 are represented by the horizontal line 88, while the position command signals for Position 3 are represented by the horizontal line 98. The ramp command signals are represented by the steep sloping line 99.
FIG. 10 is a graph of the position command signals and encoder intervals for each revolution of the needle bar utilized in the prior art electrohydraulic needle bar positioning apparatus disclosed in the prior U.S. Pat. No. 4,173,192.
In FIG. 10, the command signal representations of positions 1 and 2 corresponding to the transverse positions of the needle bar are the same as those disclosed in FIG. 6. However, since there was only one input encoder signal per revolution of the main drive shaft in the apparatus disclosed in the prior U.S. Pat. No. 4,173,192, the position command signal was generated instantaneously directing the hydraulic actuator to move at maximum speed independently of the speed of the main shaft 11 of the tufting machine during the "Shifting Window".
Accordingly, such operation caused excessive shock loads to the machinery because of the abrupt stopping and starting and change of direction of the actuator and the needle bar 18. Accordingly, such abrupt signals and changes in direction of the hardware limited the machine life as well as causing considerable noise in the operation of the tufting machine.
As disclosed in FIG. 10, the slope of the ramp line 190 is 90 deg., and therefore, produces an infinite velocity command signal.
The above description of the units and relationships, and their graphic representations in FIGS. 6-8, as well as the remaining description of the invention, and the disclosures in tee prior U.S. Pat. No. 4,173,192, are sufficient to enable one ordinarily skilled in the digital computer art with specific knowledge of microprocessors and the programming thereof, to reproduce the above described apparatus.
While the machine 10 is in operation, the rotation of the main shaft 11 produces sequential encoder signals at uniform intervals, such as 1,000 such encoder signals per shaft revolution. These encoder signals are received in the microprocessor controller 43, decoded and read. When the next encoder counts after count 91 are entered into the system, digital position ramp command signals are generated corresponding to the values defined by sloping linear ramp command line 90. The position command signals are then compared with the current feedback signals from the feedback transducer 54, corresponding to the actual position of the actuator rod 45, in a manner well known in the art of computer science in order to produce a digital drive signal. The drive signal is then multiplied by a constant value, as illustrated in the following equation:
DIGITAL DRIVE SIGNAL (D)=K [DIGITAL POSITION COMMAND SIGNAL (C)-DIGITAL FEEDBACK SIGNAL (F)]
or
D=K (C-F)
where K=a constant
The conditioned digital drive signal (D) is then compared with maximum limit levels and transmitted through the D/A converter 80 to convert the digital drive signal into an analog drive signal. The analog drive signal is then amplified in the drive circuit 81, and transmitted to the servovalve 52 to immediately actuate the valve 52 to transmit the flow of hydraulic fluid to one side of the piston 42 in order to drive the actuator rod 45 in the direction dictated by the values represented in either FIGS. 6 7, or 8, to the desired next transverse position of the needle bar 18. The initial and terminal portions of the movement of the actuator rod 45 are gradual. However, the major intermediate portion of the actuator rod movement is substantially uniform throughout its linear travel at low speeds, e.g. 350 RPM, creating a smooth transition for the needle bar 18 with a minimum of noise and wear upon the actuator and the machine parts At higher speeds, e.g. 1250 RPM, the drive signal voltage will gradually increase to about the mid-point of the needle bar travel and then gradually decrease because of the inertia of the moving machine elements or hardware.
When the encoder 34 is counting in the encoder count intervals between 0 and the early shift count 91 (Position 1) or between the terminal count 92 and 100 (Position 2), the same constant command signal is generated corresponding to position 1 or position 2. Such constant command signal is compared with an equal constant feedback signal from the transducer 54 to produce a zero drive signal, so that the needle bar 18 remains in its corresponding transverse position 1 or 2.
However, whenever, the encoder count is counting in the "Position Window" interval, the position command signals or ramp commands increase linearly (in FIGS. 6 and 8). These positive command signals are then compared with feedback signals changing with the transverse positions of the actuator rod 45, but of lesser value than the corresponding position command signals to produce the output signals, which when multiplied by the constant K generates a drive signal which ultimately causes the actuator rod 45 and needle bar 18 to shift transversely between the programmed positions 1-2 (FIG. 6), 2-1 (FIG. 7), 1-3 (FIG. 8), or other positions determined by the programmed pattern information in the PROM 71 and the interface 84.
The microprocessor based controller 43 may operate to produce signals responsive to the machine speed for actuating the yarn feed clutch system 40. At the appropriate time the clutches 100 are disengaged from the yarn feed shafts 101 to produce slack in the yarn 25 fed to the needles 20 as the needle bar 18 is moving transversely. The apparatus may be utilized without the yarn feed clutch system 40, in which event the extra yarn required by the transversely moving needles will be obtained by backrobbing the previously formed loops, in a well known manner.
Where it is desired to change the patterns of yarn formed in the backing fabric 22 by changing the transverse movements of the needle bar 18, different pattern information may be introduced into the ROM or PROM 71 by substituting other plug-in PROMS in the storage interface 84 with different pattern information permanently impressed thereon, such as disclosed in the prior U.S. Pat. No. 4,173,192, or such information may be introduced through the operator I/O terminal 38.
|
An electronic computer control for a hydraulic actuator for shifting a needle bar to different transverse positions in a tufting machine. The computer control directs the hydraulic actuator to be driven in response to the predetermined stitch pattern information in the computer control circuit, which determines the amount of relative tansverse shifting of the needle bar for each stitch location, in such a manner that the needle bar is shifted transversely only a needle gauge, or a multiple needle gauge, at a time and only while the needles are out of the backing fabric. The computer control also controls the velocity of the transverse movement of the needle bar in a gradual manner to minimize any shock created by the transverse movement of the needle bar upon the tufting machine. In order to enhance the smooth and gradual shifting movement of the needle bar, the computer control command signals commence prior to the actual commencement of needle bar shifting and terminate prior to the re-entry of the needles into the backing fabric to counteract any delayed inertial movement of the needle bar in response to the computer command signals.
| 3
|
FIELD OF THE INVENTION
This invention relates to single or dual chamber pacemakers, and more particularly to a mode of operation wherein one or more blanking periods are determined by measuring inherent noise propagation characteristics of the pacemaker system.
BACKGROUND OF THE INVENTION
In the following description, the term pacemaker refers to all implantable cardiac devices having cardiac pacing and sensing capabilities. Briefly, in these types of devices the sensed signals are fed to a sensing amplifier for amplification and signal conditioning.
This sensing amplifier disables its sensing ability for a brief period following a sensed or a paced event. The time during which sensing is disabled is called a blanking period. The blanking period prevents inappropriate sensing of residual energy by the pacemaker amplifier following an intrinsic event or a pacemaker output pulse. The blanking period may be applied to the same chamber where the event occurs. In dual chamber pacemakers, the blanking period also may be applied to the chamber other than the one in which the event occurs. In this case, the blanking period is called the cross-channel blanking period. There are eight possible blanking periods (See FIG. 1A) in a pacemaker: (1) atrial blanking period after an atrial sense, (2) atrial blanking period after an atrial pace, (3) atrial blanking period after a ventricular sense, (4) atrial blanking period after a ventricular pace, (5) ventricular blanking period after an atrial sense, (6) ventricular blanking period after an atrial pace (7) ventricular blanking period after a ventricular sense, and (8) ventricular blanking period after a ventricular pace. The blanking period is a function of sensing/pacing polarity; sensitivity; pacing amplitude, pulse width, lead maturation, and position of leads. In general, in prior art devices, the durations of these blanking periods was either fixed at the factory, or was one of the adjustable programmer parameters that had to be set by the physician either based on average values obtained from statistical data, or by trial and error.
It is advantageous to provide dual chamber pacemaker with an AMS (Automatic Mode Switching) function, as described for example, in U.S. Pat. No. 5,441,523, incorporated herein by reference. The AMS function switches the pacemaker from a rate-response mode, wherein pacing rate is determined from a physiological pacemaker to a backup pacing rate under certain pre-selected conditions. However, in such a pacemaker an extra long atrial blanking period reduces the sensitivity of the AMS function. In the worst case situation the A-V delay may be equal to or shorter than the atrial blanking period following an atrial event (blanking periods (1) or (2)). Since the A-V delay is followed by a ventricular event, which in turn causes the atrial blanking period to extend still further by a cross channel blanking period (3) or (4). If an intrinsic R-wave occurs before the end of the A-V delay, the atrial blanking period is also extended by blanking period (3). Therefore, fast atrial events associated with atrial tachycardia such as atrial fibrillation or atrial flutter may occur during this extra long blanking period and cannot be sensed by the pacemaker. Accordingly the atrial tachycardia is not detected and the pacemaker does not activate the AMS function to switch from a dual chamber to a ventricular non-tracking mode.
However, if the blanking periods are set to be too short, in channel or cross channel noise may be erroneously sensed as a cardiac event. For example for a short atrial blanking following a ventricular event, a farfield R wave may be sensed improperly as a new ventricular event.
Similarly, if a cross channel ventricular blanking period (5 or 6) is too short, an atrial event may be erroneously interpreted as a ventricular event and ventricular pacing maybe inhibited. If the same ventricular blanking period is too long however, a premature ventricular contraction may occur during this blanking period and a proper A-V delay would not be set up.
Thus, it is clear that the operation of a pacemaker would be vastly improved if the blanking periods can be set accurately and automatically to reflect and compensate for the electrical characteristics of a particular pacemaker system and/or the patient's tissues.
OBJECTIVES AND ADVANTAGES OF THE INVENTION
An objective of the present invention is to provide a pacemaker in which the sensing blanking periods are optimized for a particular patient, pacemaker or both.
A further objective is to provide a pacemaker system in which the blanking periods are determined automatically.
A further objective is to provide a pacemaker system capable of calculating both the in channel and cross channel blanking periods.
Other objectives and advantages of the invention shall become apparent from the following description.
Briefly, a pacemaker system constructed in accordance with this invention includes a pacemaker having means for generating test pulses to a cardiac chamber, and means for sensing cardiac signals corresponding to said pulses, after a preset time period. The time period required for said cardiac signals to decay is measured and this period is used to determine the duration of the in-channel and/or cross channel blanking periods for the pacemaker.
Alternatively, the duration of the blanking periods is determined externally in which case the cardiac response to other stimulation is used as a criteria.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, features and advantages of the invention will become apparent upon consideration of the following description, taken in conjunction with the accompanying drawing, in which:
FIG. 1A shows the blanking periods in a prior art dual chamber pacemaker;
FIG. 1 is a block diagram of a pacemaker which embodies the subject invention;
FIG. 2 is a block diagram of the controller of FIG. 1;
FIG. 3 is a state diagram that characterizes the operation of the pacemaker of FIG. 1;
FIG. 4 is a timing diagram showing the relationship between pacing pulses and the corresponding blanking periods in accordance with this invention;
FIG. 5 shows a circuit used to determine the blanking periods in accordance with this invention;
FIG. 6 shows a timing diagram for the circuit of FIG. 5;
FIG. 7 shows a flow chart for the circuit of FIG. 5; and
FIG. 8 shows details of a determinator circuit.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, a pacemaker 10 constructed in accordance with this invention includes a sensing circuit 12 receiving signals from the heart 14 of a patient and a pacing circuit 16 for generating pacing pulses for the heart 14. A controller 18, which is usually a digital microprocessor receives the signals from the sensor indicative of the electrical activity of the heart, and based on these signals, generates appropriate control signals for the pacing circuit 16.
Pacemaker 10 further includes a telemetry device 20 for selectively exchanging information with an external programmer 22. The pacemaker 10 and programmer 22 jointly form a pacemaker system 24.
Although the invention may be applicable to other types of pacemakers, the pacemaker in FIG. 2 is adapted to operate in a DDDR mode and as such, it receives A-sense and V-sense signals and generates A-pace and V-pace pulses. As shown in more detail in FIG. 2, the controller 18 includes a pacer state machine 24 which generates the pace signals based on the sense signals. In addition, the A- and V-sense signals are also fed to a blanking period calculator 26 which calculates and stores the blanking periods and sends corresponding blanking period signals to the sensory circuit 12.
A preferred embodiment the pacemaker state diagram is shown in FIG. 3. It should be understood that the invention is applicable to pacemakers operating in other modes as well. The PVARP is the Post Ventricular Atrial Refractory Period. An A-sense occurring during this interval is considered to be due to a retrogradely conducted ventricular event and is ignored. A V-sense occurring at any time starts the PVARP.
The API which follows the PVARP is the Atrial Protection Interval and defines the minimum time between an ignored A-sense (i.e., in the PVARP) and the next A-pace. The API is intended to prevent an A-pace being provided during the vulnerable part of the atrial repolarization period, i.e., the relative refractory period during which arrhythmias may be induced.
The Alert which may follow API, is the interval during which A-senses are classified to be P-waves (i.e., of sinus origin) within the correct rate range. Such P-waves are tracked 1:1 by the ventricular channel. The Alert is the remainder of VV interval after the sum of the AV delay plus the PVARP plus the API.
The AV delay which follows an atrial event is intended to mimic the natural P-wave to R-wave interval and is the time between an A-sense (or A-pace) and a V-pace (in the absence of a V-sense).
Importantly, the subject pacemaker further includes means for providing blanking periods in the various sensing channels during either atrial or ventricular activity. More particularly, as shown in FIG. 4, every atrial event (i.e., atrial pace or atrial sense) is followed in the atrial sensing channel by a blanking period. Moreover blanking periods in the atrial sensing channel also follow each ventricular event to inhibit cross-channel noise. In FIG. 4 the blanking periods for atrial sensing following an atrial event are designated as Baa, and the ones following a ventricular event are designated Bav. The corresponding blanking periods for the ventricular channel are also shown in the Figure and are designated as Bvv and Bva, as shown.
As previously described, the present invention pertains to the means of determining and adjusting these blanking periods to insure that the sensing channels operate accurately and reliably. In order to determine these blanking periods, the pacemaker is provided with the blanking period calculator 26. As shown in detail in FIG. 5, the calculator 26 monitors the atrial and ventricular intracardiac signals and generates its own atrial and ventricular test blanking signals Bat, Bvt, respectively.
The calculator 26 includes an atrial noise sensor 106 and a ventricular noise sensor 108. These sensors receive respectively the atrial and ventricular intracardiac signals as shown in FIG. 1. The calculator 26 also includes an atrial pace command generator 102 and a ventricle pace command generator 104. The calculator 26 further includes individual determinator elements 110-116. The operation of the calculator 26 is now described in conjunction with the graphs of FIGS. 4 and 6 and the flow chart of FIG. 7.
Preferably the determination for the various blanking periods is made (or modified) in a physician's office with the patient's pacemaker being coupled to the programmer 22 for initializing or modifying the pacemaker's operation. The programmer 22 provides the physicians with a sequence of steps that are performed to set up various programming parameters. As part of this procedure, the physician may measure and set the pacing signal threshold levels. The blanking periods may be determined and set at the same time as follows. Initially, as shown in FIG. 7, in step S200 the atrium is overdrive paced by issuing appropriate pacing command to generator 102 using a fixed A-V delay of 200 msec. This step is performed to insure that the blanking periods are determined in response to atrial pacing and not an atrial natural pulse. It is believed that blanking periods following a paced pulse in either chamber should be longer than the blanking periods following an intrinsic cardiac event. Therefore, it is safe to apply the blanking periods determined for a paced event to a sensed (intrinsic) event.
Next an atrial test pace signal 300 is generated, as indicated on FIG. 6 (Step 202). Following this signal 300, a shortened atrial test blanking signal Bat is generated by a test blanking generator 118 (FIG. 5) for the atrial sensing channel 25. A similar signal Bvt is generated by generator 118 for the ventricular sensing channel 34 (FIG. 6, Step 204, FIG. 7). These signals are selected to correspond to the time required for the sense amplifier in sensing circuit 12, sensors 106, 108 to settle. For example these test blanking periods may be in the order of 20-30 msec.
Following the test blanking signal Bat, the atrial noise sensor 106 starts monitoring the atrial intracardiac signal. As shown in FIG. 6, typically a variable noise signal 302 is sensed in response to atrial test pace signal 300. Noise signal 302 sensed in the atrium decays after a time duration Tan at which time its peak falls below the sensor threshold level ATH. The output of atrial sensor 106 is fed to determinator 110 which also receives the Bat signal. Determinator 110 measures the time duration Tan by determining the last point in time when the atrial noise sensor receives an input exceeding ATH. This time duration Tan is characteristic of the tissues of heart and other factors.
As shown in FIG. 6, concurrently with the blanking period Bat, a corresponding blanking period Bvt is also generated for the ventricular sensor. Preferably this signal is also in the range of 20-30 msec. At the end of this period, a noise signal 304 is detected by sensing circuit 12. This signal is sensed by ventricular noise sensor 108 and fed to the determinator circuit 114. Determinator circuit 114 also receives the Bvt signal. After a time period Tvn, the ventricular noise signal decays to a peak level below threshold VTH. In order to insure that the blanking period does not exceed the A-V interval, the period Tvn is limited to 80 msec (Tmax). The determinator 114 thus measures the length of signal Tvn.
As shown on FIG. 7, after the signals Tan (i), Tvn (i) are measured, the whole cycle is repeated several times until several values Tan(n), Tvn (n) are obtained. The value of `n` may be for example two. This is illustrated in FIG. 7 by steps S206, S208, S210. At this point, the parameters Tan(n), Tvn(0 . . . n) are analyzed to determine the maximum difference between the respective values. In step S214 a test is conducted to determine if the difference between any two of the parameters Tan is greater than 20 msec. If this difference is less than 20 msec, than the longest Tan (longest) is selected. In step S 216 the blanking period is then calculated or set by adding Bat+Tan (longest)+safety factor. For example the safety factor may be about 15 msec. The parameters Tvn(o . . . n) are analyzed similarly to determine in step S216 for the value Bav. These values are sent to the display of the programmer. (S218).
If in step S214 it is determined that the difference between any two measurement Tan (j) exceeds 20 msec, then in step S220 an error message is sent to the programmer which in response (S222) displays a request that the whole procedure be repeated since the first set of values are unreliable.
After the blanking periods Baa, and Bav are calculated as described above, the ventricle is paced in a manner similar the one described above to obtain the values for Bva and Bvv.
The value of Baa, Bav, Bva, Bvv are transmitted to and displayed by the programmer in step S218. These values may be used as parameters by the pacemaker or may be used as suggested values to the physician as possible programmed values for blanking periods. The value of Bva is not very important and has been included herein for the sake of completeness.
Alternatively, the pacemaker 24 itself may set its own blanking periods to the values determined as described above.
Typically, as shown in FIG. 8, in the sensing circuit for sensing the atrium, the atrial electrode 50 is connected to an amplifier 52. The output of amplifier 52 is fed to a comparator 54. The comparator compares the amplified signal sensed on line 50 with a programmable sensing threshold stored in a memory 56. Signals above this threshold are sent as an A-sense signals by the circuit 12. Sensor 106 includes a peak detector 58 which detects the peaks of the signals senses on line 50. These peaks are fed to a comparator 60. The sensor 106 also includes a divide-by-two circuit 62 which receives the sensing threshold from memory 56 and divides by two. The comparator compares the signals on line 50 with the output of circuit 62 and generates an output when the peaks detected by detector 58 fall below this output. This signal is used to determine the Baa signal as discussed above. The threshold (ATH) may be detected at 50% or less than the programmed sensitivity stored in memory 56. The advantage of this approach is that it can automatically determine a high signal to noise ratio of about 2:1.
In the embodiment described above, the ideal or suggested blanking periods are determined by the pacemaker. Alternatively, the calculation to determine the blanking period in the programmer using telemetered ECG's obtained by the pacemaker. Another alternative would be to perform the calculation on the programmer, using the main timing events (MTEs) only. MTEs are marker generated to indicate senses of intracardiac ECGs. In the case, MTEs are markers of noise senses following a paced event.
Although the invention has been described with reference to several particular embodiments, it is to be understood that these embodiments are merely illustrative of the application of the principles of the invention. Accordingly, the embodiments described in particular should be considered exemplary, not limiting, with respect to the following claims.
|
The blanking periods for an implantable cardiac device, such as a pacemaker, is determined by providing an excitation in a cardiac chamber and monitoring the corresponding cardiac activity. For in-channel blanking periods, the response from the same chamber is monitored while for cross-channel blanking period, the other cardiac chamber is monitored. The optimal blanking period is then determined based on the cardiac activity. This period is programmed directly into the device, or transmitted to an external programmer where it is used to provide guidance to a health care professional. The optimal blanking period duration may also be determined using other signals sensed by the programmer, using ECG's or MTE's.
| 0
|
FIELD OF THE INVENTION AND RELATED ART STATEMENT
This invention relates to a valve element for controlling a flow of fluid and a process of producing the same, and more particularly to a valve element of a structure suitable not only for binary control of a flow of fluid between a fully open condition and a fully closed condition but also for infinite control of a flow of fluid and a process of producing the same.
A valve element is already disclosed in Japanese Patent Laid-Open No. 61-144361 wherein a conductor loop including a plurality of pairs of strings which have inner ends coupled to each other by a coupling member and outer ends isolated from each other by an insulator layer is provided in an ink chamber formed by a base and a cover which are mounted in an opposing relationship to each other and have a plurality of outlet ports formed therein while a magnet mechanism is provided on an outside face of the cover, whereby the magnetic flux to be developed from the magnet mechanism is changed by energization of the conductor loop to displace the inner ends of the strings toward the outlet port side thereby to extrude ink within the ink chamber by way of the outlet ports.
Meanwhile, a process of producing a valve element is disclosed in Japanese Patent Laid-Open No. 59-110967 wherein the process comprises the steps of forming a conductor layer on a surface of a substrate, forming a photo-resist layer on a surface of the conductor layer, exposing the photo-resist layer to light of a pattern of a valve seat, forming by development a pattern wherein the conductor layer is exposed in the configuration of the valve seat, plating nickel on a portion of the conductor layer on which no photo-resist layer is formed in order to form a valve seat, forming a spacer at a central portion of the valve seat from photo-resist, forming another conductor layer of nickel or the like on a surface of the valve seat including the spacer, forming a pattern of a valve member on a surface of the latter conductor layer from a photo-resist, plating nickel on the surface of the conductor layer in accordance with the pattern to form a valve seat, and finally dissolving unnecessary portions of the conductor layers, photo-resist layers and spacer.
Drawbacks of such conventional techniques will now be described. The valve element disclosed in Japanese Patent Laid-Open No. 61-144361 has a drawback that it is complicated in structure because it requires a magnet mechanism. Besides, there are problems that it requires a relatively great number of man-hours for assembly thereof and it is low in accuracy in assembly because it involves a large number of parts. Further, if nickel which is one of ferromagnetic substances is used for a base of such a magnet mechanism, the magnetic flux developed from the magnet mechanism will concentrate on the base so that the density of magnetic flux around a conductor loop will become low accordingly, which will make it difficult for the conductor loop to operate in response to a change in energizing current flow therethrough. Besides, if nickel is used for strings of the conductor loop, the power consumption will increase because the strings are attracted to the magnet mechanism so that the electric resistance thereof will be increased accordingly. Because of such reasons, electro-forming of nickel cannot be adopted, and accordingly the valve element has drawbacks that the corrosion resistance is low and the high degree of accuracy in dimension cannot be maintained for a long period of time.
Meanwhile, according to the process of producing a valve element disclosed in Japanese Patent Laid-Open No. 59-110967, a valve seat and a valve member are formed by plating. However, the process is intended to produce a check valve and is not suitable as a process of producing a valve element for controlling a flow rate or for binary control to fully close or fully open a flow passage.
OBJECTS AND SUMMARY OF THE INVENTION
It is a first object of the present invention to provide a valve element which can maintain a high degree of accuracy in dimension for a long period of time and a process of producing such a valve element.
It is a second object of the present invention to provide a valve element which is suitable for controlling a flow rate or for binary control to fully close or fully open a flow passage and a process of producing the same.
It is a third object of the present invention to provide a valve element of a simplified structure and a process of producing the same.
It is a fourth object of the present invention to provide a valve element which is easy to produce and a process of producing the same.
It is a fifth object of the present invention to provide a valve element which can be produced with a high degree of accuracy and a process of producing the same.
It is a sixth object of the present invention to provide a valve element wherein the power consumption is relatively low and a process of producing the same.
It is a seventh object of the present invention to provide a valve element through which fluid can flow smoothly when a flow passage is opened and a process of producing the same.
It is an eighth object of the present invention to provide a valve element which can stop a flow of fluid with certainty when a flow passage is closed and a process of producing the same.
It is a ninth object of the present invention to provide a valve element wherein electric connection thereof to a nozzle plate and a valve beam can be made readily and a process of producing the same.
It is a tenth object of the present invention to provide a valve element wherein the durability of a valve beam can be improved and a process of producing the same.
It is an eleventh object of the present invention to provide a valve element wherein a nozzle can be made minute and a process of producing the same.
According to one aspect of the present invention, there is provided a valve element which comprises a nozzle plate having formed therein a nozzle through which fluid can pass, an insulator layer located in layer on the nozzle plate except a location of the nozzle, an electrode plate covering the insulator layer, and a valve beam made of a conductive substance and located in an opposing spaced relationship by a predetermined distance from the nozzle plate, the valve beam having at a location thereof opposing to the nozzle a yieldable portion at which a valve for opening and closing the nozzle is formed in an integral relationship. Accordingly, as the electrode plate and the valve beam are energized, the valve beam is deformed to close the nozzle with the valve thereon. Or else, it is also possible to control a voltage to be applied between the electrode plate and the valve beam to adjust the opening degree of the nozzle in order to effect flow rate control. Besides, since nickel which is superior in corrosion resistance can be used for the nozzle plate, valve beam, and electrode plate, it is easy to make the valve element a device which presents little change in dimension for a long period of time.
According to another aspect of the present invention, there is provided a process of producing a valve element which comprises a nozzle pattern forming step of forming a photo-resist layer corresponding to a nozzle on a surface of a substrate, a nozzle plate forming step of forming a metal film on the surface of the substrate and removing the photo-resist layer to form a nozzle plate having a nozzle therein, a first insulator layer forming step of forming a first insulator layer on a surface of the nozzle plate such that openings may be formed at a location opposing to the nozzle and other predetermined locations, an electrode pattern forming step of forming a photo-resist layer on a surface of the first insulator layer around a location opposing to the nozzle, an electrode plate forming step of forming a metal film on a surface of the first insulator layer and removing the photo-resist layer to form an electrode plate, a second insulator layer forming step of forming on the surface of the first insulator layer a second insulator layer which covers the electrode plate such that openings may be formed in an opposing relationship to the openings of the first insulator layer, a spacer forming a step of forming a spacer of a material different from a material of the nozzle plate on a surface of the second insulator layer including a location opposing to the nozzle and an area around the location, a valve beam pattern forming step of forming a photo-resist layer on a surface of the spacer except a location opposing to the nozzle and a location opposing to a peripheral portion of the spacer, a valve beam forming step of forming a metal film on the surface of the spacer to form a valve beam which is contiguous at an end portion thereof to the nozzle plate via one of the openings and which has a valve at a yieldable portion thereof and then removing the photo-resist, and a separating step of removing a central portion of the spacer including a portion opposing to the nozzle and then exfoliating the substrate from the nozzle plate. Accordingly, a nozzle plate, a first insulator layer, an electrode plate, a second insulator layer, a spacer, a valve beam and so on can be formed one after another in layer without depending upon an assembling operation, and besides it is enabled to form patterns for a nozzle plate, an electrode plate and a valve beam from photo-resist layers and easily form them by plating or by a thin film forming technique or the like. Accordingly, a valve element can be provided which can be produced readily with a high degree of accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a substrate showing a first embodiment of the present invention;
FIG. 2 is a side elevational view of the substrate of FIG. 1;
FIG. 3 is a perspective view of the substrate of FIG. 1 after it has passed a nozzle pattern forming step;
FIG. 4 is a side elevational view of the substrate of FIG. 3;
FIG. 5 is a perspective view of the substrate of FIG. 3 after it has passed a nozzle plate forming step;
FIG. 6 is a vertical sectional side elevational view of the substrate of FIG. 5;
FIG. 7 is a perspective view of the substrate of FIG. 5 after it has passed a first insulator layer forming step;
FIG. 8 is a vertical sectional side elevational view of the substrate of FIG. 7;
FIG. 9 is a perspective view of the substrate of FIG. 7 after it has passed an electrode pattern forming step;
FIG. 10 is a vertical sectional side elevational view of the substrate of FIG. 9;
FIG. 11 is a perspective view of the substrate of FIG. 9 after it has passed an electrode plate forming step;
FIG. 12 is a vertical sectional side elevational view of the substrate of FIG. 11;
FIG. 13 is a perspective view of the substrate of FIG. 11 after it has passed a second insulator layer forming step;
FIG. 14 is a vertical sectional side elevational view of the substrate of FIG. 13;
FIG. 15 is a perspective view of the substrate of FIG. 13 after it has passed a spacer forming step;
FIG. 16 is a vertical sectional side elevational view of the substrate of FIG. 15;
FIG. 17 is a perspective view of the substrate of FIG. 15 after it has passed a valve beam pattern forming step;
FIG. 18 is a vertical sectional side elevational view of the substrate of FIG. 17;
FIG. 19 is a perspective view of the substrate of FIG. 17 after it has passed a valve beam forming step;
FIG. 20 is a vertical sectional side elevational view of the substrate of FIG. 19;
FIG. 21 is a perspective view of an almost completed valve element after the device of FIG. 19 has passed a separating step;
FIG. 22 is a vertical sectional side elevational view of the valve element of FIG. 21;
FIG. 23 is a perspective view of a completed valve element after the element of FIG. 21 has passed a cover assembling step;
FIG. 24 is a vertical sectional side elevational view of the valve element when a nozzle thereof is closed;
FIG. 25 is a vertical sectional side elevational view showing a modified form to the valve element of FIGS. 23 and 24;
FIG. 26 is a partial plan view of a valve element showing a second embodiment of the present invention;
FIG. 27 is a vertical sectional side elevational view of a valve element showing a third embodiment of the present invention;
FIG. 28 is a plan view of a valve element showing a fourth embodiment of the present invention;
FIG. 29 is a vertical sectional side elevational view of the valve element of FIG. 28;
FIG. 30 is a plan view of a valve element for complementary explanation of the embodiment of FIG. 28;
FIG. 31 is a vertical sectional side elevational view of the valve element of FIG. 30;
FIG. 32 is a plan view of a valve element for complementary explanation of the embodiment of FIG. 30;
FIG. 33 is a vertical sectional side elevational view of the valve element of FIG. 32;
FIG. 34 is a vertical sectional side elevational view of a valve element showing a fifth embodiment of the present invention; and
FIG. 35 is a vertical sectional side elevational view of a valve element showing a sixth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the present invention will now be described with reference to FIGS. 1 to 24. At first, such a substrate 1 as shown in FIGS. 1 and 2 is prepared. The substrate 1 is formed either from a metal plate such as a stainless steel plate the surface of which is finished into a surface of a mirror by polishing or from a glass plate which has a metal film formed on a surface thereof by a suitable means such as vapor deposition. The surface of the substrate 1 is preferably formed from a metal material which has a low adhering property to nickel. From this point of view, a stainless steel plate is suitable for the surface of the substrate 1.
FIGS. 3 and 4 show the substrate 1 after it has passed a nozzle pattern forming step. At the step, a photo-resist layer 2 is formed on a surface of the substrate 1 and is exposed to light to effect development to form a pattern corresponding to a nozzle. The photo-resist layer 2 has a predetermined diameter D 1 .
FIGS. 5 and 6 show the substrate 1 after it has further passed a first nozzle plate forming step. At the step, a metal film 3 is formed on the surface of the substrate 1 and the photo-resist layer 2 is removed to form a nozzle plate 5 which has a nozzle 4 formed therein. In this instance, since the metal film 3 covers over around the photo-resist layer 2, the nozzle 4 presents a trumpet-like configuration wherein the diameter thereof gradually increases toward a surface of the nozzle plate 5. The diameter D 2 of a minimum diameter portion of the nozzle 4 is smaller than D 1 and is about 10 microns or so. It is a matter of course that the nozzle 4 corresponds to the location from which the photo-resist layer 2 is removed. The metal plate 3 is formed by nickel plating using a sulfamic acid nickel bath.
FIGS. 7 and 8 show the substrate 1 after it has further passed a first insulator layer forming step. At the step, a first insulator layer 8 is formed on a surface of the nozzle plate 5 such that an opening 6 and another pair of openings 7 are formed at a portion thereof corresponding to the nozzle 4 and at a pair of other predetermined portions thereof, respectively. The first insulator layer 8 is formed by forming a layer of photosensitive polyimide on the surface of the nozzle plate 5 and then by exposing the layer to light of a pattern for the openings 6 and 7 to effect development thereof.
FIGS. 9 and 10 show the substrate 1 after it has further passed an electrode pattern forming step. At the step, a photo-resist layer 9 is formed on a surface of the first insulator layer 8 around a location opposing to the nozzle 4.
FIGS. 11 and 12 show the substrate 1 after it has further passed an electrode plate forming step. At the step, a metal film 10 is formed on a portion of the surface of the first insulator layer 8 on which the photo-resist layer 9 is not formed and then the photo-resist layer 9 is removed from the insulator layer 8 to form an electrode plate 11. A connecting portion 12 to be connected to a power source or the like which will be hereinafter described is formed at part of the electrode plate 11. The metal film 10 is formed by non-electrolytic nickel plating and then by nickel plating in order to provide a conductor layer which has a high adhering property to the first insulator layer 8. It is to be noted that the latter nickel plating may be effected using a sulfamic acid nickel bath.
FIGS. 13 and 14 show the substrate 1 after it has further passed a second insulator layer forming step. At the step, a second insulator layer 14 is formed on the surfaces of the first insulator layer 8 and the electrode plate 11 such that openings 6 and 7 and an opening 13 may be formed in portions of the second insulator layer 14 corresponding to the openings 6 and 7 of the first insulator layer 8 and the connecting portion 12 of the electrode plate 11, respectively. The second insulator layer 14 is formed by applying photosensitive polyimide in the liquid state to the surfaces of the first insulator layer 8 and the electrode plate 11 and then by exposing, after drying, the polyimide layer to light of a pattern for the openings 6, 7 and 13 to effect development of the latter. After then, the second insulator layer 14 is heated so as to unite the same with the first insulator layer 8.
FIGS. 15 and 16 show the substrate 1 after it has further passed a spacer forming step. At the step, a spacer 15 is formed by sputtering copper on a surface of a protective layer 40 including a location opposing to the nozzle 4 and an area around the location using a suitable masking. Accordingly, the spacer 15 is formed with a thickness of 10 to 20 microns on surfaces of the protective layer 40 and the electrode plate 11 and inner faces of the nozzle 4 and the openings 6, and a recess 16 having a similar configuration to the inner face of the openings 6 is formed in the spacer 15.
FIGS. 17 and 18 show the substrate 1 after it has further passed a valve beam pattern forming step. At the step, a photo-resist layer 17 is formed on a surface of a portion of the spacer 15 other than a portion opposing to the nozzle 4 (a portion opposing to the recess 16) and a peripheral portion of the spacer 15.
FIGS. 19 and 20 show the substrate 1 after it has further passed a valve beam forming step. At the step, a metal film 22 is formed on the portion of the surface of the spacer 15 on which the photo-resist layer 17 is not formed in order to form a support frame 18 of a square profile and a valve beam 19 which has opposite ends connected contiguously to the support frame 18. The metal film 22 is formed by nickel plating and is filled also in the openings 7. Accordingly, the opposite ends of the valve beam 19 are connected contiguously to the nozzle plate 5 by way of the support frame 18. Further, the valve beam 19 has a crank-like yieldable portion 20 formed thereon which is projected in a direction perpendicular to the length thereof, and since the yieldable portion 20 of the valve beam 19 is opposed to the recess 16, a valve 21 which extends along an inner face of the recess 16 is formed at the yieldable portion 20.
FIGS. 21 and 22 show a semi-completed valve element after it has passed a separating step. At the step, a central portion of the spacer 15 is removed by etching, and the substrate 1 is exfoliated from the nozzle plate 5. Upon etching of the spacer 15, an ammonia-alkali etchant which has a pH value biased to the alkali side is used so that it may not etch any other metal film. Accordingly, the clearance between an outer circumferential face of the valve 21 and inner circumferential faces of the openings 6 and the nozzle 4 can be made uniform after the central portion of the spacer 15 has been removed. Further, since the substrate 1 is formed from a stainless steel plate while the nozzle plate 5 is made of nickel, they can be exfoliated readily from each other. It is to be noted that there is a relation h<H where H denotes a clearance between the nozzle plate 5 and the valve beam 19, and h denotes a clearance between the nozzle plate 5 and the electrode plate 11.
FIG. 23 shows a completed valve element after passing a cover assembling step. At the step, a cover 24 having an entrance 23 formed therein is sealed on and secured to a surface of the protective layer 40 thereby to form a fluid containing chamber 25 within the cover 24. A switch 27, a power source 28 and a variable resistor 29 which generally constitute a driving means 40 are connected between the nozzle plate 5 and the connecting portion 12 of the electrode plate 11.
With such a construction of the valve element as described above, as ink is introduced into the fluid containing chamber 25 by way of the entrance 23, if the internal pressure of the fluid containing chamber 25 is raised in a condition of FIG. 23, the ink will be extruded from the nozzle 4. To the contrary, if the switch 27 is turned on to apply a voltage of the power source 28 between the connecting portion 12 of the electrode plate 11 and the valve beam 19, the electrode plate 11 will attract the valve beam 19 thereto due to an attracting force caused by static electricity so that the valve 21 will close the nozzle 4 as shown in FIG. 24. Accordingly, the valve element can be used to fully open or fully close the nozzle 4, that is, the valve element can be used for binary control. However, the outflow rate of ink can be changed infinitely if the voltage to be applied is controlled by means of the variable resistor 29 in accordance with the elasticity of the valve beam 19 to change the yieldably deformed amount or distortion of the valve beam 19. In this instance, since the valve beam 19 has the yieldable portion 20 which is projected in the direction perpendicular to the length thereof, the yielding action of the yieldable portion 20 can be promoted. Consequently, the valve beam 19 can be yieldably deformed with a relatively low voltage to be applied, and accordingly the power consumption can be saved. Further, since the valve beam 19 within the fluid containing chamber 25 is connected contiguously to the nozzle plate 5, it can be connected readily to the power source. It is to be noted that the principle wherein application of a voltage between the electrode plate 11 and the valve beam 19 will cause an attracting force by static electricity to act so that the electrode plate 22 may attract the valve beam 19 thereto is quite similar to the principle disclosed in an article named "Dynamic Micromechanics on Silicon: Techniques and Devices" in IEEE TRANSACTIONS ON ELECTRON DEVICES, Vol. ED-25, No. 100, October 1978 annexed hereto.
Further, as the nozzle 4 is closed by an attracting force caused by static electricity between the electrode plate 11 and the valve beam 19, the structure of the valve element can be simplified with a magnet mechanism omitted, and nickel can be used for the nozzle plate 5, valve beam 19 and electrode plate 11. Accordingly, the corrosion resistance can be improved, and a change in dimension of the nozzle 4, valve 21 and so on can be prevented for a long period of time.
Further, the nozzle 4 presents an upwardly curved arcuate cross section. In particular, the nozzle 4 presents an arcuate cross section wherein the slope of a tangential line to the nozzle 4 comes close to the direction of the axis of the nozzle 4 toward the end of the nozzle 4. This configuration of the nozzle 4 is effective to reduce the resistance of the nozzle 4 to fluid when the fluid passes through the nozzle 4 from the valve beam 19 side. Since the valve beam 19 has a similarly arcuate cross section, the resistance thereof to fluid is reduced. Further, when the nozzle 4 is fully closed upon application of a voltage, close contact between the nozzle 4 and the valve beam 19 is assured by the arcuate configurations of them. In addition, since the openings 6 formed in the first insulator layer 8 and the second insulator layer 14 have such a configuration that they are contiguous to the nozzle 4, they are effective to reduce the resistance of the nozzle 4 to fluid when the fluid passes through the nozzle 4.
Further, the nozzle plate 5, first insulator 8, electrode plate 11, second insulator layer 14, spacer 15, valve beam 19 and so on can be layered one on another without depending upon an assembling operation, and the patterns of the nozzle plate 5, electrode plate 11 and valve beam 19 can be formed readily with a high degree of accuracy in dimension with photo-resist layers by plating or by a thin film forming technique. Since the nozzle plate 5 and the valve beam 19 are formed by an electro-forming method in this manner, they can be readily formed with a desired thickness.
Besides, since nickel plating is effected using a non-glazing sulfamic acid nickel bath in which a glazing agent is not used in order to improve the purity of the deposited nickel to lower the elasticity of the valve beam 19, the stress relative to the same distortion of the valve beam 19 can be reduced and the durability of the valve beam 19 can be improved. As a result, where the valve element is used in an ink printer, even if thermally melted ink or dyestuff steam of a high temperature is contained in the fluid containing chamber 25, the heat resistance of the valve beam 19 can be improved.
Further, if a protective layer 26 is formed by sputtering or the like of SiO 2 , Al 2 O 3 , Si 3 O 4 or a ceramic represented by a composition of these substances on a surface of the second insulator layer 14 as shown in FIG. 25, where the valve element is used in an ink printer, the insulator layers 8 and 14 made of polyimide can be protected from ink or some other dyestuff. The protective layer 26 is formed by means of a protective layer forming step between a second insulator forming step and a spacer forming step.
Now, a second embodiment of the present invention will be described with reference to FIG. 26. Like parts or elements are denoted by like reference numerals to those of the first embodiment, and description thereof will be omitted to avoid redundancy. In the present embodiment, in order for the valve element to be compatible with an ink printer, a plurality of nozzles 4 are formed in a nozzle plate 5 while a plurality of openings 6 corresponding to the nozzles 4 are formed in first and second insulator layers 8 and 14, and a plurality of valve beams 19 each having a valve 21 corresponding to one of the nozzles 4 are formed in a contiguous relationship to opposite ends of a large support frame 18. Accordingly, printing is effected while record paper is moved relative to the valve element in a direction perpendicular to a direction in which the valves 21 are arranged.
Now, a third embodiment of the present invention will be described with reference to FIG. 27. A nozzle plate 19 in the present embodiment is formed from a photosensitive glass plate or a photosensitive resin film, and an electrode plate 11 is formed directly on the nozzle plate 19.
Here, since the nozzle plate 19 has a photosensitivity, its nozzle 4 can be made finely and with a high degree of accuracy where it is worked using light. The other steps are similar to those of the first embodiment described above.
Next, a fourth embodiment of the present invention will be described with reference to FIGS. 28 and 29. At first, if a shape in which a valve beam 19 itself can be embodied is examined, the valve beam 19 can be formed as a cantilever beam as shown in FIGS. 30 and 31. However, in this instance, if a plurality of such valve beams 19 are arranged in a row, free ends thereof at which valves 21 are formed may readily be turned and the valve beams 19 are not stabilized in working nor in operation and are yieldably deformed readily because the valve beams 19 have a great length relative to the width thereof. To the contrary, it is possible for a valve beam 19 to have a configuration of a both ends supported beam as shown in FIGS. 32 and 33. In this instance, the valve beam 19 itself is stabilized, but because it is not distorted readily, a relatively high voltage is required.
From such reasons, in the present embodiment of FIGS. 28 and 29, the valve beam 19 has a configuration of a both ends supported beam but has formed at a central portion thereof via a pair of supporting portions 31 a yieldable portion which is projected in a direction perpendicular to the length of the valve beam 19. With the configuration, the stability and the yieldability of the valve beam 19 can be satisfied.
Meanwhile, since the supporting portions 13 have a reduced width in order to attain a suitable elasticity, the valve beam 19 can be yieldably distorted with a relatively low voltage. Further, in order to allow a plurality of such valve beams 19 to be arranged efficiently, the yieldable portion of each of the valve beams 19 has a pair of portions extending in oblique directions.
Now, a fifth embodiment of the present invention will be described with reference to FIG. 34. The present embodiment provides a method of securing a valve beam 19 to a nozzle plate 5, and in the present embodiment, the nozzle plate 5 is not integrated by plating with a valve beam 19 through an opening 7 as in the first embodiment described hereinabove but is secured on an insulator layer 14 via a spacer 15. In this instance, materials are selected which are high in close contactness both in a combination of the spacer 15 and the insulator layer 14 and in another combination of the spacer 15 and the valve beam 19.
Further, a sixth embodiment of the present invention will be described with reference to FIG. 35. In the present embodiment, a valve beam 19 is closely contacted with and secured directly to an insulator layer 14 but not via a spacer 15. In this instance, polyimide may be used for the insulator layer 14 while nickel may be used for the valve beam 19. In this instance, it is necessary to provide non-electrolytic nickel plating of a high close contactness on a surface of the insulator layer 14.
|
A nozzle plate in which a nozzle through which fluid can pass is formed is prepared, and an insulator layer is located in a layer on the nozzle plate except a location of the nozzle. An electrode plate is provided so as to cover the insulator layer, and a valve beam made of a conductive substance is located in an opposing relationship to the nozzle plate. A valve for opening and closing said nozzle is formed at a yieldable portion of the valve beam opposing to the nozzle. Upon energization of the electrode plate and the valve beam of a valve element thus produced, the valve is attracted toward the electrode plate to open or close the valve. Binary control of the valve to fully open or fully close the nozzle and infinite control of the valve to infinitely open or close the nozzle can be readily attained in the valve element.
| 5
|
BACKGROUND
[0001] Total vehicle height is an important design parameter for fitting on existing ship hangers and elevators, as well as fitting inside transport aircraft. As shown in FIGS. 1 and 2 A- 2 B, conventional coaxial helicopters are typically taller than other helicopters of similar performance due to the existence of an additional rotor and the flapping motion of the rotor blades necessitating a minimum vertical hub spacing (rotor separation ratio). In particular, FIG. 1 shows an upper rotor 102 coupled to an upper rotor swashplate 104 and a lower rotor 106 coupled to a lower rotor swashplate 108 . A rotor hub separation 110 may generally separate the upper rotor 102 and lower rotor 106 . FIG. 2A illustrates a single axis/rotor helicopter 202 , whereas FIG. 2B illustrates a coaxial/dual rotor helicopter 204 . As shown in FIGS. 2A-2B , the height of the helicopter 204 may be appreciably greater than the height of the helicopter 202 .
[0002] Some helicopters, such as the Sikorsky X2 Technology™ Demonstrator, may have a reduced rotor separation ratio relative to other helicopters. The reduced rotor separation ratio may be facilitated by the use of hingeless, rigid rotors which may bend rather than flap like articulated rotors do. The high blade rigidity may imply large blade moments and approximately 20% 2/rev blade bending that may increase vibratory (peak to peak) blade stresses beyond 1/rev loads alone. Though 2/rev blade bending may cancel at a hub, the 2/rev blade bending may: (1) decrease minimum blade tip clearance between the two rotors (e.g., rotors 102 and 106 ), (2) increase peak blade stresses, and (3) increase rotor blade and hub design weight. 2/rev blade control typically cannot be accomplished using an ordinary swashplate, at least for rotors with two blades or more than three blades. In some instances, it may be desirable to utilize a configuration that does not include a swashplate.
BRIEF SUMMARY
[0003] An embodiment is directed to a method of controlling a helicopter having a rotor with blades. The method includes receiving, by a computing device comprising a processor, at least one input associated with the helicopter; generating, by the computing device, control signals configured to counteract blade bending associated with the rotors based on the received at least one input; measuring, by the computing device, blade signals using sensors for the blades; extracting, by the computing device, harmonic loads from the measured blade signals; adapting, by the computing device, the control signals based on the harmonic loads; and controlling, by the computing device, servos connected to the blades to adjust the blades according to the adapted control signals to reduce vibratory loads on the blades.
[0004] Another embodiment is directed to an apparatus for use in a helicopter having at least one rotor with blades, the apparatus includes at least one processor and a memory having instructions stored thereon that, when executed by the at least one processor, cause the apparatus to receive, with the at least one processor, at least one input associated with the helicopter; generate, with the at least one processor, control signals configured to counteract blade bending associated with at least one rotor based on the received at least one input; measure, with the at least one processor, blade signals using sensors for the blades; extract, with the at least one processor, harmonic loads from the measured blade signals; adapt, with the at least one processor, the control signals based on the harmonic loads; and control, with the at least one processor, servos connected to the blades to adjust the blades according to the adapted control signals to reduce vibratory loads on the blades.
[0005] Another embodiment is directed to an aircraft having rotors, with each rotor having a plurality of blades. Each of the plurality of blades is associated with a sensor included in a plurality of sensors. The aircraft also includes a servo connected to at least one of the blades and a control computer. The control computer is configured to receive blade signals from the plurality of sensors; extract 2/rev loads from the blade signals; receive control signals for controlling the aircraft; adapt the received control signals based on the loads; and control the servo to adjust the blades to reduce a vibratory load on the blades.
[0006] Additional embodiments are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements.
[0008] FIG. 1 illustrates a coaxial, dual rotor helicopter;
[0009] FIG. 2A illustrates a single axis/rotor helicopter;
[0010] FIG. 2B illustrates a dual rotor helicopter;
[0011] FIG. 3 illustrates a control system for a coaxial, dual-rotor helicopter according to an embodiment of the invention;
[0012] FIG. 4 illustrates a control algorithm and process flow according to an embodiment of the invention;
[0013] FIG. 5 is a schematic block diagram illustrating an exemplary computing system according to an embodiment of the invention; and
[0014] FIG. 6 is a flow chart of an exemplary method according to an embodiment of the invention.
DETAILED DESCRIPTION
[0015] It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. In this respect, a coupling between entities may refer to either a direct or an indirect connection.
[0016] Exemplary embodiments of apparatuses, systems, and methods are described for using 2/rev individual blade control (IBC) feedback to reduce 2/rev blade deflections and loads. In some embodiments, one or more blade sensors may detect 2/rev bending signals. The signals may be processed and actions may be taken to null or mitigate the impact of the 2/rev loads. In some embodiments, a controller may convert from commands for lateral, longitudinal, and/or collective blade cyclic pitch (A1s, B1s, Theta) to position commands for blade actuators using a sine and cosine calculation based on a sensed angular position of a rotor.
[0017] Referring to FIG. 3 , a control environment or system 300 for a helicopter 340 is shown according to an embodiment of the invention. As illustrated, helicopter 340 includes a fuselage 342 and a rotor assembly 344 . In an embodiment, the rotor assembly 344 includes an upper rotor assembly 346 and a lower rotor assembly 348 that are co-axial and rotate in an opposite direction to each other. The upper rotor assembly 346 may include upper rotor blades 302 while the lower rotor assembly 348 may include lower rotor blades 306 . The upper and lower rotor blades 302 , 306 may turn or rotate based on IBC servos or rotary actuators. Specifically, upper rotor blades 302 may be rotated by IBC servos 308 a, 308 b which receive control signals from an upper servo controller 350 . Also, lower rotor blades 306 may be rotated by IBC servos 309 a, 309 b which receive control signals from a lower servo controller 352 . The IBC servos 308 a - 308 b, 309 a - 309 b allow for precise control of, e.g., angular position, respective upper and lower rotor blades 302 , 306 which may be facilitated by a transmission 310 .
[0018] One or more strain gages or sensors 316 a - 316 b and 317 a - 317 b may be incorporated into the one or more blades. Particularly, sensors 316 a - 316 b may be incorporated into upper rotor blades 302 and sensors 317 a - 317 b may be incorporated into lower rotor blades 306 . The sensors 316 a - 316 b, 317 a - 317 b may detect a rotor blade flatwise bending moment in the one or more of the blades 302 , 306 . The flatwise bending moment is converted to raw bending signals 322 which may be conveyed, potentially via the transmission 310 and using a slip ring (e.g., an optical slip ring), to a control computer 326 .
[0019] The control computer 326 may analyze the raw bending signals 322 and extract the 2/rev sinusoidal components from the raw bending signals 322 . Such extraction may be facilitated using a harmonic estimation algorithm, which may correspond to or be similar to a Fast Fourier Transform (FFT). The control computer 326 may generate and transmit servo control signals 334 to upper and lower servo controllers 350 , 352 , which may be transmitted to the respective IBC servos 308 a - 308 b, 309 a - 309 b via the transmission 310 . The control computer 326 may transmit to the upper and lower rotor assemblies 346 , 348 via the servo controllers 350 , 351 2/rev sine and cosine signals, also known as phase and amplitude, which may be based on aircraft flight states (e.g., airspeed).
[0020] The servo control signals 334 may adjust 2/rev actuation signals to achieve a specified 2/rev blade bending load. While a zero-valued 2/rev blade bending load may be desirable from a blade fatigue load standpoint, applying varying loads to the upper and lower rotor assemblies 346 and 348 may be beneficial to tip clearance during one or more helicopter maneuvers. Optimization of rotor lift to drag ratio (L/D) may require different input from that needed for minimizing loads. A control system 300 may reduce 2/rev loads to zero, improve efficiency based on a pilot-selectable mode for level flight, and/or maintain tip clearance during maneuvers.
[0021] Referring to FIG. 4 , a flow chart of architecture 400 is shown. The architecture 400 may be used to generate the servo control signals 334 of FIG. 3 for an aircraft. The architecture 400 may be implemented in connection with one or more devices or entities, such as the control computer 326 of FIG. 3 .
[0022] A pilot 402 may issue one or more directives regarding the operation or flight of an aircraft (e.g., helicopter). The directives may be received by a command model 404 . The command model 404 may estimate dynamics in a feed-forward fashion. For example, the command model 404 may generate an estimate of blade dynamics based on the pilot directives. The command model 404 may include models that may map inputs (e.g., pilot directives, flight measurements or parameters (e.g., airspeed, acceleration, attitude, etc.), etc.) to outputs (e.g., anticipated or estimated aircraft dynamic responses). The models may be established using simulations or wind tunnel data. The models may be refined based on system flight data. While described in terms of a pilot 402 , it is understood that the pilot can be a human pilot, or could be an autonomous or semi-autonomous pilot using one or more processors, and/or could be separate from the aircraft as in the case of an unmanned aerial vehicle.
[0023] The command model 404 may generate (primary) flight control signals as well as 2/rev signals, which may be provided to a feedback block 406 . The command model 404 may also provide input to an inverse dynamics block 408 . The inverse dynamics block 408 may predict controls to implement desired aircraft dynamics. The command model 404 and the inverse plant 408 may function as follows: the pilot 402 makes a command with an inceptor (e.g. cyclic stick), the command model 404 converts that inceptor command to an aircraft dynamic command (e.g. pitch the nose down at X degrees per second), the inverse plant 408 ideally is the inverse of an aircraft dynamics block 414 , so it takes the commanded dynamics and converts them to blade angle commands (e.g., input X deg/s pitch rate, output Y deg rotor cyclic blade pitch).
[0024] Outputs of the feedback block 406 and the inverse dynamics block 408 may be summed at a node 410 . The output of the node 410 may drive a servo control block 412 . The servo controls 412 may impact or drive the aircraft dynamic response 414 , which may be monitored or detected by blade sensors 416 and flight control sensors 418 . A 2/rev harmonic estimation block 420 may estimate 2/rev frequencies/vibrations based on the output of the blade sensors 416 . Together, the blade sensors 416 and the 2/rev harmonic estimation block 420 may be used to provide 2/rev load alleviation. The flight control sensors 418 and the 2/rev harmonic estimation block 420 may provide input to the feedback block 406 .
[0025] Referring to FIG. 5 , an exemplary computing system 500 is shown. The system 500 is shown as including a memory 502 . The memory 502 may store executable instructions as well as models used in the method described in FIG. 6 . The executable instructions may be stored or organized in any manner and at any level of abstraction, such as in connection with one or more applications, processes, routines, methods, etc. As an example, at least a portion of the instructions are shown in FIG. 5 as being associated with a first program 504 a and a second program 504 b.
[0026] The instructions stored in the memory 502 may be executed by one or more processors, such as a processor 506 . The processor 506 may be coupled to one or more input/output (I/O) devices 508 . In some embodiments, the I/O device(s) 508 may include one or more of a keyboard or keypad, a touchscreen or touch panel, a display screen, a microphone, a speaker, a mouse, a button, a remote control, a control stick, a joystick, a printer, etc. The I/O device(s) 508 may be configured to provide an interface to allow a user to interact with the system 500 .
[0027] The system 500 is illustrative. In some embodiments, one or more of the entities may be optional. In some embodiments, additional entities not shown may be included. For example, in some embodiments the system 500 may be associated with one or more networks. In some embodiments, the entities may be arranged or organized in a manner different from what is shown in FIG. 5 . One or more of the entities shown in FIG. 5 may be associated with one or more of the devices or entities described herein (e.g., the control computer 326 of FIG. 3 ).
[0028] Turning to FIG. 6 , a flow chart of a method 600 is shown. The method 600 may be executed in connection with one or more components, devices, or systems, such as those described herein. The method 600 may be used to control blade bending (e.g., 2/rev blade bending) in various flight states for an aircraft, such as a coaxial helicopter configured with individual blade control on each rotor, and can also be used to develop models in advance of flight or during flight.
[0029] In block 602 , one or more models may be developed. The models may be used to provide a prediction or estimate regarding one or more dynamic responses. For example, the models may be used to estimate blade dynamics or loads based on pilot inputs. Block 602 can be developed outside of the aircraft being flown, and therefore can be stored on the aircraft and recalled as needed in later operation. For instance, the models can be created using test data (such as wind tunnel data), or simulation data. As such, block 602 can be optional in aspects and can be performed separately from other blocks of the method of FIG. 6 .
[0030] In block 604 , one or more controls or control signals may be generated. The control signals may be generated based on the estimation models of block 602 in conjunction with input signals from, for example, a pilot. The control signals may serve to counteract the estimated dynamic responses/loads. The control signals may attempt to control higher harmonic (e.g., 2/rev) blade bending in different flight states.
[0031] In block 606 , blade signals may be measured, potentially using one or more sensors.
[0032] In block 608 , an estimation or extraction of higher harmonic loads from the measured blade signals of block 606 may be performed. Based on an identification of the higher harmonic loads in block 608 , the control signals of block 604 may be adapted. For example, the control signals of block 604 may be adapted to minimize the higher harmonic loads by switching from one model to the next.
[0033] In some embodiments, one or more of the blocks or operations (or a portion thereof) of the method 600 may be optional. In some embodiments, the blocks may execute in an order or sequence different from what is shown in FIG. 6 . In some embodiments, one or more additional blocks or operations not shown may be included.
[0034] Technical effects and benefits of aspects include, in aspects, a reduction in terms of the weight of components aboard an aircraft (e.g., a helicopter). For example, because 2/rev stresses may represent approximately 20% of the vibratory stress during level flight, 2/rev cyclic control can reduce the vibratory flatwise blade loads by approximately the same amount (20%), which may allow for a reduction in terms of a design weight of various rotor components (e.g., blades and hubs). 2/rev control may be used to improve the rotor L/D by approximately 5% relative to conventional aircraft configurations. 2/rev control may be used to improve tip clearance during maneuvers, allowing for a reduced rotor separation ratio and therefore a reduction in terms of total aircraft height. However, it is understood that aspects can have other advantages in addition to or instead of the above-noted advantages, benefits and effects.
[0035] Embodiments of the disclosure have been described in connection with aircraft/rotorcraft. Aspects of the disclosure may be applied in other environments or contexts. For example, aspects of the disclosure may be used to provide for a reduction of stress in turbine applications based on higher harmonic controls. Further, while described in the context of a specific example (2/rev), it is understood that aspects can be used in other per revolution harmonics. Additionally, while described in the context of a coaxial aircraft, it is understood that aspects can be used in single rotor aircraft, wind turbines, and other like bodies.
[0036] As described herein, in some embodiments various functions or acts may take place at a given location and/or in connection with the operation of one or more apparatuses, systems, or devices. For example, in some embodiments, a portion of a given function or act may be performed at a first device or location, and the remainder of the function or act may be performed at one or more additional devices or locations.
[0037] Embodiments may be implemented using one or more technologies. In some embodiments, an apparatus or system may include one or more processors, and memory storing instructions that, when executed by the one or more processors, cause the apparatus or system to perform one or more methodological acts as described herein. Various mechanical components known to those of skill in the art may be used in some embodiments.
[0038] Embodiments may be implemented as one or more apparatuses, systems, and/or methods. In some embodiments, instructions may be stored on one or more computer-readable media, such as a transitory and/or non-transitory computer-readable medium. The instructions, when executed, may cause an entity (e.g., an apparatus or system) to perform one or more methodological acts as described herein.
[0039] Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional.
|
A method of controlling a helicopter having a rotor with blades is provided. The method includes receiving, by a computing device comprising a processor, at least one input associated with the helicopter; generating, by the computing device, control signals configured to counteract blade bending associated with the rotors based on the received at least one input; measuring, by the computing device, blade signals using sensors for the blades; extracting, by the computing device, harmonic loads from the measured blade signals; adapting, by the computing device, the control signals based on the harmonic loads; and controlling, by the computing device, servos connected to the blades to adjust the blades according to the adapted control signals to reduce vibratory loads on the blades.
| 8
|
BACKGROUND OF THE INVENTION
This invention relates to new polyurethane compositions as well as to a process for curing polyurethane prepolymers.
Polyurethane elastomers have found wide application in the manufacture of articles that must be tough, flexible, and abrasion-resistant; for example, in shoe soles and heels, automobile tire sidewalls, industrial belts, and molded auto parts such as bumper inserts or covers. Normally, the polyurethane prepolymer, the curing agent, and the catalyst are well mixed, placed in a mold, and heated until at least substantial curing has taken place. At this point, the polyurethane article can be demolded without danger of loss of shape or of mechanical integrity and completely cured in an oven.
It is desirable to reduce the molding time as much as possible, so that the mold output can be increased. One way to achieve this goal is to use a small amount of a curing agent having more than two active hydrogen groups together with the normal curing agent having only two active hydrogen groups, usually a diol. Because the polyfunctional additive causes some crosslinking, gelling occurs quite readily, and the partly crosslinked polymer has sufficient mechanical strength to be able to withstand demolding and handling after a short residence in the mold. For many applications, however, a crosslinked polyurethane elastomer is less desirable because it has lower tear strength and elongation. It thus is important to reduce the polyurethane molding time without producing a highly crosslinked polyurethane elastomer.
SUMMARY OF THE INVENTION
According to the present invention, there is now provided a curable polyurethane prepolymer composition consisting essentially of a reaction product of the following components (A) and (C) with (B):
(A) 1 mole of a polymeric glycol having a number average molecular weight of about 400-3000;
(B) at least 1.3 moles of an organic diisocyanate; and
(C) a blocking agent having at least three active hydrogen groups per molecule capable of reacting with isocyanate groups, the proportion of the blocking agent being about 0.01 to 0.15 active hydrogen equivalent per equivalent of isocyanate groups in excess of hydroxyl groups;
with the proviso that when the blocking agent is a phenol/aldehyde resin, its proportion is at most 5% by weight of component (A).
There also is provided a process for making cured polyurethane elastomer articles, wherein the following composition is first blended together and molded at a sufficiently high temperature to cause crosslinking of the prepolymer, thereby to impart to the shaped article adequate mechanical integrity to permit the article to be demolded prior to complete cure:
(A) 1 mole of a polymeric glycol having a number average molecular weight of about 400-3000;
(B) at least 1.3 moles of an organic diisocyanate;
(c) about 0.01 to 0.15 equivalent of an isocyanate-blocking agent having at least three active hydrogen groups per equivalent of isocyanate groups in excess of hydroxyl groups;
with the proviso that when the blocking agent is a phenol/aldehyde resin, its proportion is at most 5% by weight of component (A)
(D) a diol having aliphatic hydroxyl groups and a molecular weight of less than about 250,
the amount of the diol being equivalent to at least 75%, but no more than about 120%, of the diisocyanate (B) in excess of the polymeric glycol (A);
then, the crosslinked molded article is demolded and maintained at a temperature of about 25°-150° C. until cure is completed;
with the proviso that, instead of a mixture of components (A), (B), (C), and (D), one can use a mixture of (D) or of (D) and one of (A) and (C) with the product of a one-step or a two-step reaction of the remaining components with one another.
DETAILED DESCRIPTION OF THE INVENTION
The compositions of the present invention can be made by combining the polymeric glycol, the diisocyanate, and the blocking agent either all at once or in a stepwise manner. For example, the glycol and the blocking agent can first be mixed together and then combined with the diisocyanate. Or, the diisocyanate and the glycol can first be made to react with each other, and the blocking agent is added last. Similarly, the blocking agent and the diisocyanate can be made to react first, and the glycol is added last. The preferred compositions of the present invention are those obtained by first making an isocyanate-terminated polyurethane prepolymer from the diisocyanate and the polymeric glycol, then combining this prepolymer with the isocyanate-blocking agent. Since the proportion of the blocking agent is quite small, the reaction product, even though branched, normally still is soluble in the reaction mixture, which remains fluid and pourable. When this fluid composition is mixed with the diol (D) and poured into a mold and heated to about 100°-120° C., further chain extension of the branched prepolymer takes place, so that the composition forms a three-dimensional network of good mechanical integrity. The shaped article can now be removed from the mold without danger of damage and left at ambient or higher temperature for several minutes or hours, preferably in an oven. This part of the cure following demolding can be referred to as post-cure. If the proportion of the diol is sufficient to displace the blocking agent, the blocked isocyanate groups now unblock and react with the hydroxyl groups of the diol. The completely cured polyurethane is completely or at least predominantly linear. The blocking agent or its thermal degradation product, which normally will be nonvolatile, remains in the cured polyurethane as a harmless, uniformly dispersed additive.
The preferred proportion of the diisocyanate in the compositions of the present invention is 1.5-6 moles per mole of polymeric glycol. Naturally, with increasing proportions of the diisocyanate, there will be an increasing amount of free diisocyanate in the compositions of the present invention in addition to the diisocyanate that will be chemically bound in the prepolymer by reaction with the polymeric glycol and polyfunctional blocking agent.
The polymeric glycols which are used in the practice of this invention include polyoxyalkylene ether glycols and polyester glycols. Glycols having number average molecular weights of about 600-2000 are especially effective in giving high quality polyurethanes. Illustrative of suitable polyoxyalkylene ether glycols are poly-1,2-propylene ether glycol, poly-1,3-propylene ether glycol and polytetramethylene ether glycol, the latter being especially preferred. Block and random copolymers of ethylene and propylene oxide are also useful, particularly ethylene oxide-capped polypropylene ether glycol. Polyoxyalkylene ether glycols can be prepared by condensing epoxides or other cyclic ethers, either by themselves or with simple diols, as is well known in the art.
Suitable polyesters include polycaprolactones and polyesters based on dicarboxylic acids, such as adipic, succinic and sebacic acids, and low molecular weight glycols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol and 1,6-hexanediol. The polycaprolactones are prepared by condensing caprolactone in the presence of minor amounts of difunctional active hydrogen compounds such as water or a low molecular weight glycol. Polyesters based on dicarboxylic acids and glycols can be made by well-known esterification or transesterification procedures. Polyesters based on mixtures of glycols and/or mixtures of diacids are useful because they often yield polyurethanes having good low temperature properties.
The organic diisocyanates which can be used to prepare the polyurethanes of this invention include aromatic and aliphatic (including cycloaliphatic) diisocyanates. Representative aromatic diisocyanates include 4,4'-methylenebis(phenyl isocyanate), 2,4- and 2,6-tolylene diisocyanate and mixtures thereof, 1,3- and 1,4-phenylene diisocyanate, 4,4'-methylenebis(o-tolyl isocyanate), 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, and 4,4'-oxybis(phenyl isocyanate). Representative aliphatic isocyanates include hexamethylene diisocyanate, 1,3- and 1,4-cyclohexylene diisocyanate, 1,3- and 1,4-xylylene diisocyanates, 3,3,5-trimethyl-5-isocyanatomethylcyclohexyl isocyanate and 4,4'-methylenebis(cyclohexyl isocyanate). Preferred isocyanates include 4,4'-methylenebis (phenyl isocyanate), 2,4-tolylene diisocyanate and mixtures thereof with 2,6-tolylene diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate) and 3,3,5-trimethyl-5-isocyanatomethylcyclohexyl isocyanate. Especially preferred in the present invention is 4,4'-methylenebis (phenyl isocyanate), also known as MDI.
The diols used as curing agents in this invention can have primary or secondary aliphatic hydroxyl groups. Diols having primary hydroxyl groups are preferred. While the diols must have aliphatic hydroxyl groups, diols containing aromatic rings such as 1,4-di(β-hydroxyethoxy)benzene, are suitable. Illustrative diols include 1,4-butanediol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, cis and trans-1,4-dihydroxycyclohexane and 1,4-di(β-hydroxyethoxy)benzene, 1,3-butanediol, 2-methyl-2-ethyl-1,3-propanediol, 2-methylbutanediol-1,4, 2-butyl-2-ethylpropanediol-1,3 and 2-alloxymethyl-2-methylpropanediol-1,3. Preferred diols include 1,4-butanediol, ethylene glycol and 1,4-di(β-hydroxyethoxy)benzene. The preferred proportion of the curing diol is equivalent to 90-105% of the diisocyanate in excess of the polymeric glycol.
The polyfunctional blocking agents contemplated for use in the present invention may contain groups such as hindered secondary amino groups which can be represented by the general formula ##STR1## where R 1 and R 2 are alkyl, and R 3 and R 4 are hydrogen or alkyl; phenolic hydroxy groups; oxime groups; or hydroxamic acid groups.
Examples of suitable polyfunctional blocking agents containing hindered secondary amino groups include (1) polyamines prepared by the addition of secondary and tertiary amines to polyacrylate and polymethacrylate esters of low molecular weight polyols having three or more hydroxyl groups such as the addition product of three moles of t-butylamine to one mole of trimethylolpropane triacrylate and (2) polyamines prepared by vinyl polymerization of hindered amino group-containing vinyl monomers such as t-butylaminoethyl methacrylate and a variety of monomers which can be prepared by adding less than equivalent amounts of secondary and tertiary amines to polyacrylate esters so that at least one double bond will still be available for vinyl polymerization.
Examples of suitable polyfunctional blocking agents containing phenolic hydroxy groups include (1) substantially uncrosslinked phenol/aldehyde resins having at least three hydroxyl groups prepared by condensation of phenol or substituted phenols such as cresol or t-butylphenol with lower aldehydes such as formaldehyde and acetaldehyde, (2) polyesters of p-and m-hydroxybenzoic acids with low molecular weight polyols having at least three hydroxy groups; for example, the tri(4-hydroxybenzoate) of trimethylolpropane, (3) commercial polyfunctional phenolic antioxidants such as 1,3,5-trimethyl-2,4,6-tri(3,5-di-t-butyl-4-hydroxybenzyl) benzene and (4) polyphenols such as phloroglucinol.
Typical polyfunctional blocking agents containing oxime groups or hydroxamic acid groups can be prepared by reacting hydroxylamine with the carbonyl groups in certain polymers such as terpolymers of ethylene, methyl acrylate and carbon monoxide to yield a polyoxime or by reacting hydroxylamine with the ester groups of a dipolymer of ethylene and methyl acrylate to yield a polyhydroxamic acid.
Preferred blocking agents include substantially uncrosslinked phenol/formaldehyde resins and the polymers of t-butylaminoethyl methacrylate. These polymeric materials are soluble in the starting glycol-diisocyanate mixtures, either at room temperature or with heating.
Reactions of the isocyanate groups with the blocking agents containing secondary amino groups occur spontaneously. When both the blocking agent and the diol curing agent are present in the reaction medium, the blocking agent reacts preferentially, so that premature curing with the diol does not occur. The nonbasic polyfunctional blocking agents, however would not selectively react with the isocyanates in the presence of the aliphatic diol. When both such a blocking agent and the curing diol are present in the reaction medium, it is necessary to catalyze the blocking reaction. Suitable catalysts are tertiary amines. These can be aliphatic, aromatic, cycloaliphatic, or mixed and should not be substituted with strongly electron-withdrawing (e.g., --NO or --NO 2 ) groups. Suitable catalysts include, for example, tributylamine, N,N-dimethylaniline, N-ethylmorpholine, triethylenediamine, and N,N-dimethylcyclohexylamine. The amount of the catalyst usually will be about 0.001 to 0.5% based on the combined weight of compounds (A) and (B), preferably 0.003 to 0.1%.
It is to be noted that phenolic hydroxy groups, oxime groups, and hydroxamic acid groups react with the --NCO groups even in the absence of a catalyst, so that it is not necessary to use catalysts when the curing diol is absent during the isocyanate-blocking reactions.
As follows from the Summary of the Invention, the process of the present invention can be carried out in one step, by starting with all four components (A), (B), (C), and (D); or, for example, with a mixture of (C) and (D) with a polyurethane prepolymer obtained in a separate reaction of (A) with (B); or with a mixture of (D) with the blocked polyurethane prepolymer obtained in two separate reactions by first forming the prepolymer from (A) and (B), then blocking it with (C); or with a mixture of (D) with a blocked prepolymer obtained in a separate reaction from a mixture of (A), (B), and (C). Irrespective of the process variant, the overall chemical structures and physical properties of the cured polyurethanes prepared by these alternative different routes are sufficiently close to make these materials virtually undistinguishable from one another. In all these process variants the blocking agent (C) reacts before the curing agent (D) and, if the stoichiometry is such that the blocked isocyanate groups are unblocked, eventually a mixture of the cured polyurethane with the free blocking agent or with a derivative or degradation product of the blocking agent is obtained. Not all the blocked groups will always necessarily unblock, depending to a large extent on the relative proportions of the blocking agent and of the diol as well as on the process conditions, especially temperatures. The resulting polymer may thus not be completely linear but may contain a small proportion of crosslinks. While for most applications a completely linear polyurethane elastomer is preferred, the partly crosslinked polyurethane also is a useful product. It is particularly suitable for use in those applications where it may come in contact with organic liquids which would dissolve or swell a linear polyurethane to a greater extent.
The process of the present invention can be carried out within a temperature range of about 25°-150° C., usually about 80°-130° C. The same temperature range can be maintained during the molding stage and the post-cure stage; however the molding and the post-cure temperatures need not be identical. Using the present process, a shaped polyurethane article can be removed from the mold in 20-50% the time required in the absence of a polyfunctional blocking agent. The post-cure step normally requires several hours. Post-cure temperatures at the lower end of the acceptable range, that is, near 25° C., are possible with such polyfunctional blocking agents as, for example, the hindered secondary amines, which are readily displaced by the curing diol.
The polyurethane prepolymer, which may be used as one of the starting materials according to one of the process variants is made from components (A) and (B) in the presence or absence of a catalyst in a manner generally known in the art. A typical prepolymer preparation may follow, for example, the teachings of U.S. Pat. No. 3,752,790 to McShane. In order to avoid premature cure in the molding step and instability on storage, it is preferred not to use a catalyst in the prepolymer preparation.
Similarly, the reaction of the prepolymer with a blocking agent preferably is not catalyzed, so that the fabricator, who may be in a different location, may add the type and amount of catalyst of his choice with the curing diol and carrying out the last step of the process according to his preference.
The blocked polyurethane prepolymers of the present invention are valuable intermediates which can be formulated with any suitable curing agents and optionally with catalysts and cured to polyurethane articles. The blocked prepolymers which are supplied by the chemical manufacturer to the user for molding and curing thus are useful articles of commerce.
This invention is now illustrated by the following examples of certain representative embodiments thereof, where all parts, proportions, and percentages are by weight unless otherwise indicated.
Physical property data were obtained according to the following ASTM procedures:
______________________________________Modulus at 100% elongation, M.sub.100 D412Modulus at 300% elongation, M.sub.300 D412Modulus at 500% elongation, M.sub.500 D412Tensile at break, T.sub.B D412Elongation, E.sub.B D412Hardness, Shore A and D D2240Bashore Resilience D2632Compression set D395Tear, die C D624Trouser tear D470______________________________________
The 180° C. bend test is employed as a rapid means for determining the state of cure of a molded polyurethane. The test is conducted on a molded polyurethane test slab within 30 seconds of opening the mold, while the slab is still hot upon removal from the mold. The test is conducted by lifting one corner of a 6 in.×6 in.×75-mil (15.2 cm×15.2 cm×0.1905 cm) molded slab of polyurethane and bending the corner over until it touches the upper surface of the slab and while maintaining the corner in contact with the surface of the slab, pressing down on the resulting fold. A very poorly cured sample will break at the fold. A well-cured sample upon release will return essentially to its original shape and there will be no significant mark or crease where the fold was pressed. Cracking at the bend without breaking or evident creasing at the bend indicate an incomplete cure.
EXAMPLE 1
A prepolymer is prepared by reacting in the absence of a catalyst, at 100° C., 3.3 moles of 4,4'-methylenebis (phenyl isocyanate) with 1.0 mole of poly(tetramethylene ether) glycol having a number average molecular weight of about 1000. The prepolymer has an NCO content of 10.1%. The prepolymer is cured with 1,4-butanediol, optionally in combination with a soluble phenol-formaldehyde resin having a molecular weight of about 1200 (Resinox® 753, sold by Monsanto Chemical Company), in the presence of triethylenediamine catalyst. The amounts of materials used are shown in Table Ia.
TABLE Ia______________________________________ Parts 1-C 1-DIngredients 1-A 1-B (Control) (Control)______________________________________Prepolymer 100 100 100 100Phenol-formal- 1.29 1.29 -- --dehyde resin1,4-Butanediol 9.67 10.8 10.8 9.67Triethylene- 0.03 0.03 0.03 0.03diamine, 33%solution inisopropylalcohol______________________________________
The phenol/formaldehyde resin is dissolved in the prepolymer by heating to 110° C. The resulting solutions are cooled to 50° C., at which point most of the resin has not reacted. Butanediol and triethylenediamine catalyst are then added, and the mixtures are degassed by agitating at 70° C. under reduced pressure. The mixtures are poured into molds preheated to 110° C. The molds are maintained at 110° C. until the samples can be demolded without breaking or tearing. Samples I-A and 1-B can be demolded in 8 and 10 minutes, respectively, while Sample 1-C cannot be demolded before at least 30 minutes, and Sample 1-D cannot be demolded at all. Sample 1-A is cured with 90% of the theoretical amount of butanediol required to react with all of the NCO originally contained in the prepolymer, while Sample 1-B is cured with the theoretical amount of butanediol. Control Sample 1-C is cured with butanediol alone in the theoretical amount. Control Sample 1-D is cured with butanediol alone at a level of 90% of the calculated amount. Portions of Samples 1-A,, 1-B and 1-C are tested after being demolded with and without post-curing for 16 hours at 110° C. The results of these physical tests are shown in Table Ib.
TABLE Ib______________________________________ Sample 1-A 1-B 1-C______________________________________Physical PropertiesAfter Mold Cure OnlyHardness A 93 92 92Hardness D 51 49 52M.sub.100, MPa 14.97 13.08 13.08M.sub.300, MPa -- 27.54 24.62T.sub.B, MPa 29.09 27.54 46.14E.sub.B, % 280 300 450Permanent Set, % 17 28 46Tear D470, kN/m 13.5 18.94 27.01Compression Set 22 hrs./70° C. 61 55 37Bashore Resilience 41 39 43Physical PropertiesAfter Post Cure for16 hrs./110° C.Hardness A 92 91 92Hardness D 47 47 48M.sub.100, MPa 14.11 12.56 13.08M.sub.300, MPa 38.56 25.82 26.17T.sub.B, MPa 39.60 36.84 36.50E.sub.B, % 300 380 380Permanent Set, % 20 34 37Tear D470, kN/m 11.92 23.50 23.68Compression Set 22 hrs./70° C. 51 36 36Bashore Resilience 38 37 39______________________________________
It can be seen from the above data that samples 1-B and 1-C, both cured with the calculated amount of 1,4-butanediol, after post-cure have similar physical properties. Following the molding step, but before post-cure, sample 1-B, made from a composition containing phenol/formaldehyde resin, has the physical properties of a crosslinked product, while control sample 1-C, made without the resin, is a typical undercured product. Sample 1-A, cured with less than the theoretical amount of 1,4-butanediol, remains crosslinked even after post-cure, as evidenced by its lower tear strength and elongation.
EXAMPLE 2
An isocyanate-terminated prepolymer prepared from 4,4'-methylenebis(phenyl isocyanate) and poly(ethylene adipate) glycol and having an NCO content of 6.3% (Multrathane® F-242 sold by Mobay) is modified by reacting it with the phenol-formaldehyde resin of Example 1 in the presence of triethylenediamine catalyst. The phenol-formaldehyde resin is dissolved by heating the reacting mixture to 110° C. for 10 minutes. A complete reaction of the resin takes place during this period. This modified prepolymer is cured with different proportions of ethylene glycol. Control runs with the unmodified prepolymer also are made. The amounts of materials used are shown in Table IIa. The "NCO equivalents, %" figures indicate what percentage of the NCO groups in the original unmodified prepolymer would be cured by the amount of ethylene glycol added.
TABLE IIa______________________________________ Run A B C D______________________________________Prepolymer, parts 100 100 100 100Phenol-formaldehyderesin, parts 1.6 1.6 1.6 1.6Triethylenediamine,parts 0.1 0.1 0.1 0.1Ethyleneglycol (parts 4.83 4.6 4.37 4.14(NCO equi-(valents, % 105 100 95 90______________________________________ Run E F GPrepolymer, parts 100 100 100Phenol-formaldehyderesin, parts -- -- --Triethylenediamine,parts 0.1 0.1 0.1Ethyleneglycol (parts 4.83 4.6 4.37(NCO equi-(valents, % 105 100 95______________________________________
The samples are prepared by mixing the ethylene glycol with the modified or unmodified prepolymer at 70° C. and degassing the mixture at 70° C., after which the mixture is poured into molds preheated to 110° C. Samples are demolded after one hour at 110° C. and tested by subjecting them to the 180° bend test. All samples except G pass the bend test after the one-hour mold cure. Physical properties are determined on portions of the cooled samples without further cure and also on portions after post-curing for 72 hours at 110° C.
The test data are shown in Table IIb. Data for Sample G are not included because the sample did not cure.
TABLE IIb______________________________________Physical Properties A B C______________________________________No Post CureHardness A 79 77 79Hardness D 26 31 33100% Modulus, MPa 4.6 4.8 5.5300% Modulus, MPa 8.4 10.2 12.8Tensile Strength, MPa 12.8 21.9 29.5Elongation at Break, % 425 495 490Tear Strength, D470 kN/m 11.6 14.7 13.9Compression Set (Method B) 83 79 6822 hrs./70° C. %Bashore Resilience 27 25 23Post Cured 72 hrs.at 110° C.Hardness A 74 73 75Hardness D 28 31 31100% Modulus, MPa 4.2 4.7 4.6300% Modulus, MPa 9.1 10.7 12.9Tensile Strength, MPa 14.8 25.0 34.6Elongation at Break, % 450 585 575Tear Strength, D470 kN/m 19.5 21.2 20.7Compression Set (Method B) 69 66 4522 hrs./70°C., %Bashore Resilience 24 26 22______________________________________Physical Properties D E F______________________________________No Post CureHardness A 79 82 83Hardness D 33 38 37100% Modulus, MPa 6.4 5.7 5.9300% Modulus, MPa 21.0 12.1 13.3Tensile Strength, MPa 32.1 38.0 46.7Elongation at Break, % 365 630 640Tear Strength, D470 kN/m 15.4 22.6 21.5Compression Set (Method B) 59 52 4822 hrs./70° C., %Bashore Resilience 22 38 34Post Cured 72 hrs.at 110° C.Hardness A 73 81 77Hardness D 30 34 33100% Modulus, MPa 4.5 4.9 4.8300% Modulus, MPa 12.2 11.9 11.6Tensile Strength, MPa 33.6 33.4 40.5Elongation at Break, % 560 665 720Tear Strength, D470 kN/m 22.2 23.5 25.1Compression Set (Method B) 44 47 4822 hrs./70° C., %Bashore Resilience 20 35 33______________________________________
EXAMPLE 3
Cured polyurethane samples are prepared substantially as described in Example 2 employing the quantities shown in Table III. Minimum demold time is determined for each sample as the minimum time at which the sample passes the 180° bend test without breaking. Table III shows the minimum demold times observed and physical properties of the samples after a 72-hour post-cure at 110° C.
TABLE III______________________________________ A B C D______________________________________Prepolymer, parts 100 100 100 100Phenol-formaldehyderesin, parts 1.6 1.6 1.6 1.6Ethylene glycol,parts 4.6 4.46 4.14 4.83NCO equivalents, % 100 97 90 105Minimum demold-time,Minutes 29 27 45 21Hardness A 77 79 76 81Hardness D 33 34 32 34100% Modulus, MPA 5.7 5.9 5.4 5.0300% Modulus, MPA 13.8 15.2 17.4 10.3Tensile Strength,MPa 41.7 25.0 38.0 13.7Elongation atBreak, % 550 390 480 390Tear Strength, D-470, kN/m 21.9 22.8 17.0 21.0Compression Set(Method B)22 hrs/70° C., % 43 26 25 33______________________________________ Controls E F G H______________________________________Prepolymer, parts 100 100 100 100Phenol-formaldehyderesin, parts -- -- -- --Ethylene glycol,parts 4.6 4.46 4.14 4.83NCO equivalents, % 100 97 90 105Minimum demold-time,Minutes >65 >75 >80 >60Hardness A 82 81 80 --Hardness D 36 34 33 --100% Modulus, MPA 5.8 5.5 5.3 5.5300% Modulus, MPA 12.8 13.8 12.6 13.2Tensile Strength,MPa 47.9 38.0 55.9 21.6Elongation atBreak, % 550 480 500 390Tear Strength, D-470, kN/m 23.5 23.5 10.5 23.3Comp. Set (Method B)22 hrs/70° C., % 25 21 17 --______________________________________
The demold times of compositions A through D are significantly shorter than the demold times of prior art compositions E through H. After post-cure, the properties of compositions A through D are quite acceptable.
EXAMPLE 4
The prepolymer of Example 1 is modified by adding to 17,114 g of the prepolymer a solution of 8.6 g of azobisisobutyronitrile in 376.5 g (2.2 phr) of t-butylaminoethyl methacrylate with stirring. The resulting mixture is heated to 110° in a degasser and held for 10 minutes to effect the acrylate polymerization. This modified prepolymer is cured with a mixture of butanediol and trimethylolpropane in the presence of triethylenediamine as catalyst, the respective weight proportions of these components being 97/3/0.3.
Samples are cured with different proportions of the curing mixture as shown in Table IV below, and are tested after mold cure only for 1 hour at 110° C. and after a 16-hour post-cure at 110° C. All the procedures are those of Example 1. The physical properties of the samples are shown in Table IV.
TABLE IV______________________________________ A B C______________________________________Curing Agent, NCOequivalents, % 92 88 99Mold Cure OnlyHardness A 93 93 93Hardness D 49 50 49100% Modulus, MPa 14.3 14.3 13.2300% Modulus, MPa 22.7 22.5 17.4Tensile Strength, MPa 36.5 36.0 24.2Elongation at Break, % 435 440 490Tear Strength, D470 kN/m 25.2 20.5 23.8Tear Die C 84.1 84.8 86Compression Set (Method B) 63 -- --22 hrs./70° C., %Post-Cured 16 hrs./110°Hardness A 92 93 93Hardness D 47 47 48100% Modulus, MPa 13.0 12.8 13.0300% Modulus, MPa 21.1 20.7 20.2Tensile Strength, MPa 39.5 30.8 40.1Elongation at Break, % 455 400 480Tear Strength, D470 27.5 -- --Tear Die C 95.4 90.4 95.4Compression Set (Method B) 56 -- 5222 hrs./70° C., %______________________________________
All the samples have adequate physical properties.
EXAMPLE 5
A prepolymer is prepared by reacting 3.0 moles of 4,4'-methylenebis(phenyl isocyanate) with 1.0 mole of poly(tetramethylene ether)glycol having a number average molecular weight of about 1000. The prepolymer has an NCO content of 9.3%. It is cured with a combination of diols and a hindered triamine (trimethylolpropane tri-β-t-butylaminopropionate), hereafter, BATA. BATA is prepared by adding 3 moles of t-butylamine to 1 mole of trimethylolpropane triacrylate and letting the mixture stand overnight. At the end of this period, no unsaturation remains in the product. The amounts of materials used are shown in Table Va. The percentages given in the table represent the percentage of the NCO groups in the prepolymer which would theoretically react with the various curing agents.
TABLE Va______________________________________ ControlsComponent, parts (%) A B C D______________________________________Prepolymer 100 100 100 100BATA (%) 3.49 -- -- 3.7 (10%) (10%)1,4-Butanediol (%) 8.05 8.46 9.46 8.46 (80%) (85%) (95%) (85%)Dipropylene glycol (%) -- 1.48 -- 1.48 (10%) (10%)Total (%) (90%) (95%) (95%) (105%)______________________________________
The prepolymer is heated to 110° C. and BATA is added slowly with rapid stirring over a period of 5 minutes. The mixture is cooled to 55° C.; the diols are added; and the mixture is further mixed, degassed, and poured into molds preheated to 110° C. The molds are maintained at 110° C. for 30 minutes; then, the samples are demolded. Samples A and D can be demolded without breaking. The control samples B and C, break, however. Portions of demolded samples A, B, C, and D are tested with and without post-curing 16 hours at 110° C. The physical properties shown in Table Vb indicate that sample D has lower tear strength and elongation before post-curing than after. Samples B and C follow the normal pattern expected for prior art polyurethanes of decreasing tear strengths and elongations with postcuring.
TABLE Vb______________________________________Sample A B C D______________________________________ Strong Strong and and Flexible, Flexible, PassesDemolding Passes Cheesy, Cheesy, BendBehavior Bend Test Breaks Breaks TestMold Cure OnlyModulusM.sub.100, MPa -- 9.0 11.0 7.6ModulusM.sub.200, MPa -- 11.4 13.4 10.0ModulusM.sub.300, MPa -- 14.1 15.9 12.4Tensile StrengthT.sub.B, MPa -- 29.0 26.9 30.7Elongation BreakE.sub.B, % -- 690 620 610Tear StrengthD-470, Tear,kN/m -- 24.9 31.5 19.3Post Cured16 hours/110°ModulusM.sub.100, MPa 6.9 7.9 9.7 6.9ModulusM.sub.200, MPa 9.3 11.4 13.1 8.6ModulusM.sub.300, MPa 11.7 15.9 17.2 10.0Tensile StrengthT.sub.B, MPa 31.0 48.3 31.7 15.2Elongation of BreakE.sub.B, % 620 570 480 660Tear StrengthD-470 Tear,kN/m 22.8 22.8 23.6 23.6______________________________________
|
Polyurethane prepolymers having free isocyanate groups are treated with polyfunctional isocyanate-blocking agents to cause branching prior to or simultaneously with the addition of a curing diol. The composition containing the curing diol is molded in a conventional equipment at a conventional temperature, e.g., 100°-120°C. The resulting shaped article can be demolded in a fraction of the time required in the absence of the blocking agent. The shaped article is then post-cured within a temperature range of about 25°-150° C., during which time the curing diol, if present in sufficient amount, displaces the blocking agent and forms a cured, linear polyurethane. A typical suitable blocking agent is a substantially uncrosslinked phenol/formaldehyde resin. The curable composition can be prepared in one step from the diisocyanate, glycol, and blocking agent; and a composition containing all the components, including the curing diol, can be prepared in one or more steps. If a nonbasic blocking agent is used in the presence of the curing diol, it is recommended to use a tertiary amine catalyst to selectively catalyze the blocking, rather than the curing, reaction. The cured linear polyurethanes have good physical properties, comparable with those of the prior art polyurethane elastomers. Partly crosslinked cured polyurethanes find utility where resistance to organic liquids is important.
| 2
|
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA Contract and is subject to the provisions of Section 305 of the National Aeronautics & Space Act of 1958. Public Law 85-568 (72 STAT 435; 42 U.S.C. 2457).
This is a continuation of application Ser. No. 161,257, filed June 20, 1980, now abandoned.
BACKGROUND OF THE INVENTION
The invention generally relates to a method for driving two-phase turbines and more particularly to a method for reducing friction loss and low efficiency for multi-stage turbines adapted to be driven by a flow of a liquid-gas mixture, herein referred to as a two-phase fluid.
DESCRIPTION OF THE PRIOR ART
Heretofore, it has been common practice to drive turbines employing a liquid, such as water, or a gas, such as steam, herein simply referred to as a single-phase fluid. In systems designed to utilize steam and the like, multi-staging of turbines is relied upon to permit the angular velocity or tip speed of the turbine blades to be low, when compared to the incoming flow speed or velocity of the single-phase fluid. Such staging frequently is referred to as "Curtis" staging. In these systems, increased fluid friction acting on the blades is considered to be an acceptable price to pay, particularly since fluid friction generally is not considered to constitute a serious impairment to efficiency. Furthermore, the velocity of the tips of the turbine blades, when compared to the linear velocity of the flow of the fluid, must be low in order to maintain the mechanical integrity of the turbine.
In systems designed to utilize a liquid, such as water, fluid friction generally is not considered to constitute a serious impairment to efficiency because of the laminar flow characteristics of the boundary layer established by the liquid as it is caused to flow over the surfaces of the blades of the turbines.
As is well known by those familiar with two-phase fluids, however, where the quantity of the liquid in a flow of two-phase fluids is relatively low, when compared to the total for the two-phase flow, the liquid tends to attach itself to the surfaces of the blades so that the relative velocity thus established between the two-phase liquid and the turbine blades is reduced due to the dissipating effects of the friction. Of course, as the quantity of the flow of liquid is increased, the relative velocities of the flow increases, relative to the velocity of the turbine blades, due to the laminar flow established as the liquid passes over the surfaces of the blades.
Heretofore, even though the angular velocity of the tips of the turbine blade in a two-phase system has been deemed to be acceptably low, due to the effect of friction of the liquid passing over the blades, widespread use of such systems has not been experienced because, at least in part, it commonly has been accepted that suitably high efficiency for turbines designed to be driven by two-phase fluids simply was not obtainable.
It is therefore the general purpose of the instant invention to provide a method through which a turbine may be driven using a two-phase fluid with the efficiency thereof being enhanced through a reduction in friction drag.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the instant invention to provide a method through which the efficiency of two-phase turbines is enhanced.
Another object is to provide in a method for driving a two-phase turbine the step of maintaining the angular velocity of the rotor thereof in a value such that the angular velocity of the tips of the rotor blades is a velocity equal to at least 50% of the velocity of a flow of two-phase fluid as the fluid is introduced into the turbine.
These and other objects and advantages are achieved through a method wherein the angular velocity of the rotor is maintained at a value such that the angular velocity of the tips of the blades of the rotor is a velocity equal to at least 50% of the velocity of the flow of a two-phase fluid as the flow is introduced into the turbine, the velocity of the rotor being controlled through the output shaft of the turbine.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a two-stage, two-phase turbine adapted to be driven employing the method embodying the principles of the instant invention.
FIGS. 2a and 2b comprise diagrammatic views depicting computation of efficiency for two-phase turbines where the relative velocity of the fluid and the blades of the turbine is zero.
FIG. 3 is a diagrammatic view depicting computation of efficiency for a two-stage, two-phase turbine wherein the velocity of the exiting fluid flow relative to the velocity of the turbine blades is greater than zero.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, with more particularity, there is shown in FIG. 1 a two-stage, two-phase turbine system generally designated 10. Since the structural details of the turbine system 10 forms no part of the claimed invention, a detailed description thereof is omitted in the interest of brevity.
The system 10, as illustrated, however, includes a two-stage, two-phase turbine generally designated 12 connected with a suitable source of two-phase fluid, not shown, via a two-phase nozzle 14. A typical two-phase fluid comprises a water/air mixture ratio of 10:1 by mass.
The turbine 12 includes a first stage, not designated, having a turbine rotor 16, as well as a second stage having a turbine rotor 18. The rotors 16 and 18 are of a bladed design and are connected with a turbine output shaft 20, via a suitable gear box 22. In practice, the gear box 22 serves to connect the rotors 16 and 18 to the output shaft 20 in a manner such that the ratio of the angular velocities of the rotors 16 and 18 is maintained at a constant ratio of 2:1. As is also illustrated in FIG. 1, the turbine system 10 includes a suitable gas-liquid discharge manifold, the function of which should be apparent. It is believed sufficient to note that the rotors 16 and 18 comprise bladed rotors through which is caused to flow a two-phase fluid, injected into the nozzle 14, and that this fluid eventually exits the system via the manifold 24.
It is important to note, however, that the load applied to the shaft 20 is calculated and applied in a manner such that the angular velocity or speed of the rotor 16 is such that the tips of the blades achieve a tangential velocity of at least 50% of the linear velocity of the flow of the two-phase fluid as it exits the nozzle 14. It is known in the prior art to control the velocity of rotor blades through the application of a load applied to an output shaft. A common example is a turbine connected to an electric generator wherein the generator must be synchronized with the electrical power grid to which its power lines are connected. Thus, the actual speed of the turbine blades will be dictated by the synchronization of the electric generator. Since the ratio of the angular velocities for the rotors 16 and 18 is 2:1, it should be apparent to those familiar with tip speeds of rotors of turbines designed for two-phase fluid systems that the tip speed or angular velocity for the tips of the rotors 16 and 18 is "high" relative to the linear velocity of the incoming flow of two-phase fluid.
Referring for a moment to FIG. 2a, therein is illustrated computation for a "worst-case" condition for the system shown in FIG. 1. In this condition, it is assumed that the relative velocity of the two-phase fluid as it passes over the turbine blades is zero. In other words, as illustrated, the two-phase fluid enters the first stage of the system 10 at a velocity of three, any unit, designated 3 JET, while the velocity of the tips of the blades of the rotor 16 is 1.5, designated 1.5 BLADE. Thus the fluid enters the turbine at a speed of 1.5, relative to the blade, designated 1.5 REL. However, because of frictionally induced velocity losses, the fluid exits the rotor at an absolute exit velocity of 1.5, 1.5 OUT, so that the relative velocity of the fluid flow and the tips of the turbine blades is equal to zero, 0 REL.
The kinetic energy of the jet, or jet power, is one-half the jet velocity squared, JET POWER=3 2 /2=4.5. The force of the flow exerted on the blade is equal to momentum change, FORCE=3-1.5=1.5; the power output is equal to the force of the flow multiplied by the velocity of the blade, POWER=(1.5)(1.5)=2.25; and the efficiency of the turbine is equal to the output power divided by the kinetic energy of the jet, EFFICIENCY=2.25/4.5=1/2, or 50%.
Using known computational methods, it can be calculated that the efficiency of the system 10 is equal to the ratio of N/N+1, where N equals the number of stages in the turbine.
In order to calculate the efficiency for the two-stage, two-phase turbine, depicted in FIG. 1, it is noted that the power out for each stage, FIG. 2b, is determined with the output power for both stages being computed and then totaled and divided by the kinetic energy of the velocity as it is introduced to the question. For example, note that for the first stage, FORCE=3-2=1, and POWER=(1)×(2)=2, while the FORCE (of the second stage)=2-1=1 and POWER=(1)×(1)=1. The TOTAL POWER (for the two-stage system)=2+1=3, and EFFICIENCY=3/4.5=2/3 or 66.6%.
At most practical flow conditions, the liquid velocity loss is not as great as depicted in FIGS. 2a and 2b, and higher efficiencies are in fact realized. As indicated in FIG. 3, where the angles of the flow of two-phase fluids are ignored and it is assumed that the two-phase fluid possesses a velocity relative to the velocity of the tips of the blades of each stage, a higher efficiency can be expected. For example, for the first stage, as depicted in FIG. 3, JET POWER=(0.5)(150 2 )=11,250; FORCE=150-88=62; POWER=(62)(112)=6944. The output power for the second stage is computed as follows: FORCE=88-25=63; POWER=63×45=2835. Hence, TOTAL POWER=6944+2835=9779.
By dividing the total power, or 9779 by the kinetic energy, or jet power 11250, an efficiency of 87% is computed.
In view of the foregoing, it is believed to be readily apparent that the present invention provides a solution to the problem of large friction loss and low efficiency, previously encountered, utilizing two-phase flow in turbines.
|
A method for driving a two-phase turbine 10 characterized by an output shaft 20 having at least one stage including a bladed rotor connected in driving relation with the shaft, and wherein a two-phase fluid is introduced into said one stage at a known flow velocity and caused to pass through the rotor for imparting angular velocity thereto, the speed of the rotor being controlled so that the angular velocity of the tips of the blades thereof is a velocity equal to at least 50% of the velocity of the flow of the two-phase fluid.
| 5
|
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to an intake member of a resin including a generally cylindrical main section of a resin, and a subsidiary section of a resin which is integrally connected to an outer periphery of the main section, and a process for producing the same.
2. DESCRIPTION OF THE RELATED ART
A process for forming a mixture body block of a carburetor which is an intake member for an engine, using a resin by injection molding, has been proposed in Japanese Patent Application Laid-open No. 62-196115.
A member such as the mixture body block requires less accuracy in dimension and hence, could be formed from a resin which is generally not so accurate in dimension, as compared with a metal. A member such as a throttle body which is an intake member for an engine, however, requires a sufficiently high dimensional accuracy at its inner peripheral surface, because a clearance between the inner peripheral surface of such member and an outer peripheral surface of a throttle valve accommodated in the throttle body and turned therein exerts a large influence to the idling performance of the engine.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a process for forming an intake member for an engine that requires a high accuracy in dimension, from a resin by molding, and an intake member of a resin produced in such process. To achieve the above object, according to a first aspect and feature of the present invention, there is provided a process for producing an intake member of a resin by injection molding, in which the intake member includes a generally cylindrical main section of a resin, and a subsidiary section of a resin integrally connected to an outer periphery of the main section, wherein the process comprises a primary molding step of forming the main section in a primary molding die, and a secondary molding step of subsequently inserting the formed main section into a secondary molding die to form the subsidiary section integrally with the main section in the secondary molding die.
With the above feature, the main section formed at the primary molding step is generally cylindrical and has no large difference in thickness among its respective portions. Therefore, the shrinkage and warping generated during cooling can be suppressed to the minimum, thereby enabling the main section to be provided with a higher roundness or circularity. Moreover, the subsidiary section integrally connected to an outer periphery of the cylindrical main section is formed by the secondary molding step subsequent to the primary molding step and therefore, an intake member of resin having a desired shape can be finally produced.
According to a second aspect and feature of the present invention, in addition to the first feature, at the primary molding step, a molten resin is supplied through a disk gate to axially one end of a cavity of the primary molding die.
With the above feature, by supplying the molten resin through the disk gate to axially one end of the cavity in the primary molding die at the primary molding step, the resin can be poured uniformly into the cavity to prevent the orientation of a filler contained in the resin, thereby producing an intake member of a resin having a higher accuracy.
According to a third aspect and feature of the present invention, in addition to the first or second feature, the die temperature at an inner peripheral surface of the main section is set lower than the die temperature at an outer peripheral surface of the main section at the primary molding step.
With the above feature, the die temperature at the inner peripheral surface of the main section is set lower than die the temperature at the outer peripheral surface of the main section. Therefore, the inner peripheral surface of the main section can be cooled in advance to prevent the generation of shrinkage and warping, leading to a further increased roundness of the inner peripheral surface.
According to a fourth aspect and feature of the present invention, in addition to the first or second feature, the intake member of resin is a throttle body having a throttle valve turnably supported therein.
With the above feature, since the intake member of the resin is the throttle body, the roundness of the throttle body can be increased, whereby the clearance between the inner peripheral surface of the throttle body and an outer periphery of the throttle valve can be uniformized, leading to an enhanced idling performance of an engine.
According to a fifth aspect and feature of the present invention, in addition to the fourth feature, a pair of boss portions for supporting a stem portion of the throttle valve is integrally formed on the main section at the primary molding step.
With the above feature, when the main section is formed, the pair of boss portions for supporting the stem portion of the throttle valve is formed on the main section. Therefore, not only the accuracy of the boss portions can be enhanced, but also the number of forming the boss portions can be suppressed to the minimum.
According to a sixth aspect and feature of the present invention, in addition to the first feature, different types of resin materials are used for forming the main section and the subsidiary section.
With the above feature, the freedom degree of selecting the material according to the demand for a dimensional accuracy and the demand for a reduction in cost is increased.
According to a seventh aspect and feature of the present invention, in addition to the first feature, the intake member is integrally formed by injection-molding a super engineering plastic as a resin material in a cavity of the primary molding die and injection-molding a general-purpose engineering plastic as a resin material in a cavity of the secondary molding die.
With the above feature, the demands for a dimensional accuracy and a reduction in cost can be reconciled by injection-molding the super engineering plastic or the general-purpose engineering plastic depending on each portion in the intake member.
According to an eighth aspect and feature of the present invention, there is provided a process for producing an intake member of a resin by injection molding, in which the intake member includes a generally cylindrical main section, and a subsidiary section integrally connected to an outer periphery of the main section, wherein the process comprises a primary molding step of forming the main section in a primary molding die, and a secondary molding step of subsequently inserting the formed main section into a secondary molding die to form the subsidiary section integrally with the main section in the secondary molding die, wherein the same type of a resin material is used for forming the main section and the subsidiary section.
With the above feature, the main section formed at the primary molding step is generally cylindrical and has no large difference in thickness among its respective portions. Therefore, the shrinkage and warping generated during cooling can be suppressed to the minimum, thereby enabling the main section to be provided with a higher roundness or circularity. Moreover, the subsidiary section integrally connected to an outer periphery of the cylindrical main section is formed at the secondary molding step subsequent to the primary molding step and therefore, an intake member of resin having a desired shape can be finally produced. In addition, the same type of resin material is used for forming the main section formed at the primary molding step and the subsidiary section formed at the secondary molding step. Therefore the main section and the subsidiary section can be easily integrally formed in a satisfactorily conformed fashion, leading to a further increased roundness of the main section. Moreover, one type of resin material may be injected and hence, an injection molding apparatus can be simplified to reduce the equipment cost.
According to a ninth aspect and feature of the present invention, in addition to the eighth feature, the resin material is a super engineering plastic or a general-purpose engineering plastic.
With the above feature, the performance and the cost can be freely selected depending on the degree of priority by properly using the super engineering plastic which provides an enhanced dimensional accuracy in a product, but is expensive, or the general-purpose engineering plastic which provides a slightly lower dimensional accuracy in a product but is inexpensive.
According to a tenth aspect and feature of the present invention, there is provided an intake member of a resin including a generally cylindrical main section of a resin, and a subsidiary section of a resin integrally connected to an outer periphery of the main section, wherein the main section is formed in a primary molding die at a primary molding step, and subsequently the formed main section is inserted into a secondary molding die in which the subsidiary section is formed integrally with the main section at a secondary molding step.
With the above feature, the main section primarily formed is generally cylindrical and has no large difference in thickness among its respective portions. Therefore, the shrinkage and warping generated during cooling can be suppressed to the minimum, thereby enabling the main section to be provided with a higher roundness or circularity. Moreover, the subsidiary section integrally connected to an outer periphery of the cylindrical main section is formed at the secondary molding step subsequent to the primary molding step and therefore, an intake member of resin having a desired shape can be finally produced.
According to an eleventh aspect and feature of the present invention, in addition to the tenth feature, at the primary molding step, a molten resin is supplied through a disk gate to axially one end of a cavity of the primary molding die.
With the above feature, by supplying the molten resin through the disk gate to axially one end of the cavity of the primary molding die at the primary molding step, the resin can be poured uniformly into the cavity to prevent the orientation of a filler contained in the resin, thereby producing an intake member of resin having a higher accuracy.
According to a twelfth aspect and feature of the present invention, in addition to the tenth or eleventh feature, the die temperature at an inner peripheral surface of the main section is set lower than the die temperature at an outer peripheral surface of the main section at the primary molding step.
With the above feature, the temperature of the die at the inner peripheral surface of the main section is set lower than the temperature of the die at the outer peripheral surface of the main section. Therefore, the inner peripheral surface of the main section can be cooled in advance to prevent the generation of shrinkage, leading to a further increased roundness of the inner peripheral surface.
According to a thirteenth aspect and feature of the present invention, in addition to the tenth or eleventh feature, the intake member of resin is a throttle body having a throttle valve turnably supported therein.
With the above feature, since the intake member of resin is the throttle body, the roundness of the inner peripheral surface of the throttle body can be enhanced, whereby the clearance between the inner peripheral surface of the throttle body and an outer periphery of the throttle valve can be uniformized, leading to an enhanced idling performance of an engine.
According to a fourteenth aspect and feature of the present invention, in addition to the thirteenth feature, a pair of boss portions for supporting a stem portion of the throttle valve is integrally formed on the main section at the primary molding step.
With the above feature, when the main section is formed, the pair of boss portions for supporting the stem portion of the throttle valve is formed on the main section. Therefore, not only the accuracy of the boss portions can be enhanced, but also the number of steps for forming the boss portions can be suppressed to the minimum.
According to a fifteenth aspect and feature of the present invention, in addition to the tenth feature, different types of resin materials are used for forming the main section and the subsidiary section.
With the above feature, the freedom degree of selecting the resin material according to the demand for a dimensional accuracy and the demand for a reduction in cost is increased.
According to a sixteenth aspect and feature of the present invention, in addition to the tenth feature, the intake member is integrally formed by injection-molding a super engineering plastic as a resin material in a cavity of the primary molding die and injection-molding a general-purpose engineering plastic as a resin material in a cavity of the secondary molding die.
With the above feature, the demands for a dimensional accuracy and a reduction in cost can be reconciled by injection-molding the super engineering plastic or the general-purpose engineering plastic depending on each portion in the intake member.
According to a seventeenth aspect and feature of the present invention, there is provided an intake member of a resin including a generally cylindrical main section of a resin, and a subsidiary section of a resin integrally connected to an outer periphery of the main section, wherein the main section is formed in a primary molding die at a primary molding step, subsequently, the formed main section is inserted into a secondary molding die, in which the subsidiary section is formed integrally with the main section at a secondary molding step, wherein the same type of a resin material is used for forming the main section and the subsidiary section.
With the above feature, the main section primarily formed is generally cylindrical and has no large difference in thickness among its respective portions. Therefore, the shrinkage and warping generated during cooling can be suppressed to the minimum, thereby enabling the main section to be provided with a higher roundness or circularity. Moreover, the subsidiary section integrally connected to an outer periphery of the cylindrical main section is formed by the secondary molding step subsequent to the primary molding step and therefore, an intake member of resin having a desired shape can be finally produced. In addition, the same type of resin material is used for forming the main section formed at the primary molding step and the subsidiary section formed at the secondary molding step. Therefore, the main section and the subsidiary section can be easily integrally formed in a satisfactorily conformed fashion, leading to a further increased roundness of the main section. Moreover, one type of resin material may be injected and hence, an injection molding apparatus can be simplified to reduce the equipment cost.
According to an eighteenth aspect and feature of the present invention, in addition to the seventeenth feature, the resin material is a super engineering plastic or a general-purpose engineering plastic.
With the above feature, the performance and the cost can be freely selected depending on the degree of priority by properly using the super engineering plastic which provides an enhanced dimensional accuracy of a product, but is expensive, or the general-purpose engineering plastic which provides a slightly lower dimensional accuracy of a product but is inexpensive.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 10 show a first embodiment of the present invention, wherein
FIGS. 1A to 1 C are views showing shapes of a throttle body at respective steps;
FIG. 2 is a horizontal sectional view (a sectional view taken along a line 2 — 2 in FIG.3) of a throttle body forming mold at a primary molding step;
FIG. 3 is a sectional view taken along a line 3 — 3 in FIG. 2;
FIG. 4 is a view similar to FIG. 3, but for explaining the operation;
FIG. 5 is an enlarged view taken along a line 5 — 5 in FIG. 2;
FIG. 6 is a horizontal sectional view (a sectional view taken along a line 6 — 6 in FIG. 7) of the throttle body forming mold at a secondary molding step;
FIG. 7 is a sectional view taken along a line 7 — 7 in FIG. 6;
FIG. 8 is a view similar to FIG. 7, but for explaining the operation;
FIG. 9 is an enlarged view taken along a line 9 — 9 in FIG. 6;
FIG. 10 is a graph showing the roundness or circularity of a main section of the throttle body;
FIGS. 11A to 11 E are views showing a throttle body at respective steps according to a second embodiment of the present invention; and
FIGS. 12A and 12B are views showing the shapes of a throttle body according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described with reference to FIGS. 1A to 10 .
First, the structure of a throttle body 1 as an intake member of a resin produced by a process of the present invention will be described with reference to FIGS. 1A to 1 C. As shown in FIG. 1C, the throttle body 1 is comprised of an inner main section 2 , a subsidiary section 3 integrally formed on an outer periphery of the main section 2 , and an icing-preventing pipe 4 of copper, which is supported on the outer periphery and embedded in the subsidiary section 3 .
As shown in FIG. 1A, the main section 2 made of the resin includes a cylindrical portion 2 1 formed into a cylindrical shape having a small taper, a flange portion 2 2 integrally formed at axially one end of the cylindrical portion 2 1 and coupled to an engine body, and a pair of boss portions 2 3 , 2 3 integrally provided on an outer peripheral surface of the cylindrical portion 2 1 to protrude therefrom. An annular groove 2 4 is defined in the flange portion 2 2 , so that an O-ring is fitted into the groove 2 4 , and a plurality of locking projections 2 5 are formed on the outer peripheral surface of the cylindrical portion 2 1 . A circular throttle valve 5 accommodated in the cylindrical portion 2 1 is supported at its stem 6 on the boss portions 2 3 , 2 3 and driven in opening and closing movement by a throttle actuator which is not shown. The main portion 2 is formed in an injection molding manner at a primary molding step by a primary molding die. At least the cylindrical portion 2 1 in the vicinity of the throttle valve 5 is formed into a straight shape having no taper.
As shown in FIG. 1B, the pipe 4 is temporarily supported, at a pipe setting step subsequent to the primary molding step, on the plurality of locking projections 2 5 provided on the cylindrical portion 2 1 of the main section 2 to protrude therefrom.
As shown in FIG. 1C, the subsidiary section 3 of the resin is formed in an injection molding manner at a secondary molding step subsequent to the pipe setting step by a secondary molding die. The subsidiary section 3 is integrally provided with an air passage portion, a reinforced portion, a cord supporting portion, a portion attached to the main section and the like, in addition to a pipe-embedded portion in which the pipe 4 is embedded. The subsidiary section 3 is integrally formed to cover the outer periphery of the main section 2 .
The structure of a throttle body molding die will be described below with reference to FIGS. 2 to 9 .
The throttle body molding die includes a stationary plate 11 , and a movable plate 12 which is movable in a direction of an arrow A-A′ relative to the stationary plate 11 by a drive source which is not shown. A pair of upper and lower slide guides 13 and 14 are fixed to the movable plate 12 , and a slider 15 is slidably carried between both the slide guides 13 and 14 .
The slider 15 is connected to an output rod 16 a of a cylinder 16 fixed to the movable plate 12 and is slidable in a direction of an arrow B-B′ in FIG. 2 . As shown in FIG. 2, when the cylinder 16 is contracted, the slider 15 is stopped in a primary molding position, and as shown in FIG. 6, when the cylinder 16 is expanded, the slider 15 is stopped in a secondary molding position.
A generally columnar movable core 23 protruding toward the stationary plate 11 is fixed to the slider 15 . A primary molding upper slide core 24 1 and a secondary molding upper slide core 24 2 are vertically slidably carried on a guide rail 12 a which is vertically mounted at an upper portion of the movable plate 12 , and a primary molding lower slide core 25 1 and a secondary molding lower slide core 25 2 are vertically slidably carried on a guide rail 12 b which is vertically mounted at a lower portion of the movable plate 12 .
Therefore, the primary molding upper slide core 24 1 and the secondary molding upper slide core 24 2 are lifted and lowered simultaneously with each other, and likewise, the primary molding lower slide core 25 1 and the secondary molding lower slide core 25 2 are lifted and lowered simultaneously with each other. The primary molding upper slide core 24 1 is provided with a core pin 26 1 , and the primary molding lower slide core 25 1 is provided with a core pin 27 1 . In addition, the secondary molding upper slide core 24 2 is provided with a core pin 26 2 , and the secondary molding lower slide core 25 2 is provided with a core pin 27 2 .
A primary molding stationary core 28 1 and a secondary molding stationary core 28 2 are provided in the stationary plate 11 in positions where they are opposed to the movable core 23 which is located in the primary molding position or the secondary molding position. Four inclined pins 29 1 , 29 2 , 30 1 and 30 2 are fixed to the stationary plate 11 , so that the distance between tip ends of each pair of them are vertically increased toward the movable plate 12 . Two of these inclined pins 29 , and 30 1 are slidably provided to extend through the primary molding upper slide core 24 1 and the primary molding lower slide core 25 1 , and the remaining two inclined pins 29 2 and 30 2 are slidably provided to extend through the secondary molding upper slide core 24 2 and the secondary molding lower slide core 25 2 . Four recesses 12 c , 12 d , 12 e and 12 f are defined in the movable plate 12 in order to avoid the interference of the movable plate 12 with tip ends of the inclined pins 29 1 , 29 2 , 30 1 and 30 2 during clamping of the mold.
Thus, when the movable core 23 is located in the primary molding position shown in FIGS. 2 and 3, a primary molding cavity C 1 for forming the main section 2 of the throttle body 1 is defined by a primary molding die D 1 comprising the movable core 23 , the primary molding upper slide core 24 1 , the primary molding lower slide core 25 1 and the primary molding stationary core 28 1 . When the movable core 23 is located in the secondary molding position shown in FIGS. 6 and 7, a secondary molding cavity C 2 for forming the subsidiary section 3 of the throttle body 1 is defined by a secondary molding die D 2 comprising the movable core 23 , the secondary molding upper slide core 24 2 , the secondary molding lower slide core 25 2 and the secondary molding stationary core 28 2 .
A disk gate 31 is defined between opposed surfaces of the movable core 23 and the primary molding stationary core 28 1 , and connected to the entire area of one end of the primary molding cavity, and a runner 32 extending through the stationary plate 11 and the primary molding stationary core 28 , is connected to the center of the disk gate 31 . A runner plate 33 is superposed on a back of the stationary plate 11 for movement away from and toward the stationary plate 11 , and a runner 35 connected to the runner 32 is defined in the stationary plate 11 opposed to the runner plate 33 . Two runners 36 , 36 connected to one end of the secondary molding cavity C 2 extend through the stationary plate 11 and the primary molding stationary core 28 1 . A runner 37 connected to the runners 36 , 36 is defined to the stationary plate 11 opposed to the runner plate 33 .
As shown in FIGS. 5 and 6, a switch-over valve 38 for distributing a molten resin into the primary molding cavity C 1 and the secondary molding cavity C 2 is provided at a portion of the stationary plate 11 which is opposed to the runner plate 33 . The switch-over valve 38 includes a first spool 40 slidable by a rod 39 , and a second spool 42 slidable by a rod 41 . The first and second spools 40 and 42 are driven in opposite directions by a drive source which is not shown.
When the switch-over valve 38 is in the primary molding position shown in FIG. 5, a sprue 43 extending through the runner plate 33 is connected to the runner 35 which is connected to the primary molding cavity C, through a groove 40 a in the first spool 40 , and is disconnected from the runner 37 which is connected to the secondary molding cavity C 2 by a land 42 b of the second spool 42 . When the switch-over valve 38 is in the secondary molding position shown in FIG. 9, the sprue 43 is connected to the runner 37 which is connected to the secondary molding cavity C 2 through the groove 42 a in the second spool 42 , and is disconnected from the runner 35 which is connected to the primary molding cavity C 1 by the land 40 b of the first spool 40 .
The operation of the embodiment of the present invention will be described below.
First, at the primary molding step, the movable plate 12 is moved toward the stationary plate 11 in a state in which the cylinder 16 has been contracted and the slider 15 has been stopped in the primary molding position, as shown in FIGS. 2 and 3, thereby clamping the movable core 23 , the primary molding upper slide core 24 1 , the primary molding lower slide core 25 1 and the primary molding stationary core 28 1 of the primary molding die D 1 . At this time, the switch-over valve 38 is in a state shown in FIG. 5, and the molten resin supplied from the sprue 43 is supplied via the groove 40 a in the first spool 40 , the runner 35 , the runner 32 and the disk gate 31 to the primary molding cavity C 1 , whereby the main section 2 of the throttle body 1 shown in FIG. 1 is formed in an injection molding manner.
The main section 2 formed at the primary molding step is generally cylindrical and has a thickness uniform in various portions, and the generation of a shrinkage and a warping during cooling is suppressed to the minimum. Therefore, the inner peripheral surface of the main section 2 requiring a dimensional accuracy can be formed in a truly circular shape with a high accuracy. In addition, the molten resin can be supplied uniformly to the entire area of the primary molding cavity C 1 through the disk-shaped disk gate 31 . Therefore, the flow of the molten resin can be prevented from being disturbed to inhibit the orientation of a filler contained in the molten resin and further to enable a high-accuracy molding. Moreover, the pair of boss portions 2 3 , 2 3 for supporting the stem 6 of the throttle valve 5 can be integrally formed on the main section 2 by the core pins 26 1 and 27 1 provided on the primary molding upper slide core 24 1 and the primary molding lower slide core 25 1 , respectively, thereby reducing the number of treating steps.
When the primary molding step has been completed in the above manner, the movable plate 12 is moved away from the stationary plate 11 , and in operative association with this movement, the primary molding upper slide core 24 1 and the primary molding lower slide core 25 1 guided by the inclined pins 29 1 and 30 1 are moved vertically away from each other, thereby opening the primary molding die D 1 . At the next pipe setting step, the pipe 4 is temporarily supported on the plurality of locking projections 2 5 provided on the cylindrical portion 2 1 of the main section 2 to protrude therefrom, as shown in FIG. 1 B.
Then, when the cylinder 16 is expanded, causing the slider 15 integral with the movable core 23 to be moved to the secondary molding position shown in FIGS. 6 and 7, the movable core 23 , the secondary molding upper slide core 24 2 , the secondary molding lower slide core 25 2 and the secondary molding stationary core 28 2 of the secondary molding die D 2 are clamped by moving the movable plate 12 again toward the stationary plate 11 . During the clamping, the secondary molding upper slide core 24 2 and the secondary molding lower slide core 25 2 are moved toward each other, while being guided by the inclined pins 29 2 and 30 2 .
At this time, the switch-over valve 38 is in a state shown in FIG. 9, and the molten resin supplied from the sprue 43 is supplied via the groove 42 a in the second spool 42 , the runner 37 and the runners 36 , 36 into the secondary molding cavity C 2 , whereby the subsidiary section 3 of the throttle body 1 shown in FIG. 1C is formed by injection molding to cover the main section 2 . Then, the movable plate 12 is moved away from the stationary plate 11 to open the secondary molding die D 2 , and the throttle body 1 which is formed by injection molding is withdrawn. Thereafter, the cylinder 16 is contracted, causing the slider 15 to be returned to the primary molding position shown in FIG. 2, thus completing the steps of one cycle.
In the present embodiment, the same type of resin materials are used in both of the primary and secondary molding steps. The main section 2 and the subsidiary section 3 of the throttle body 1 are formed from the same type of resin materials.
In this way, the main body 2 having a uniform wall thickness is first formed in a precision molding manner at the primary molding step, and the subsidiary section 3 having an non-uniform wall thickness is then formed at the secondary molding step to cover the main section 2 . Therefore, the dimensional accuracy of the inner peripheral surface of the main section 2 can be remarkably enhanced, as compared with a case where the main section 2 and the subsidiary section 3 are formed in a single molding step.
In addition, since the same type of a resin material is used in the primary molding and secondary molding, the main section 2 and the subsidiary section 3 are integrally formed with a good conformation, leading to a further increased degree of circularity or roundness of the inner peripheral surface of the main section 2 . Moreover, the injection molding apparatus may be arranged to be able to accommodate the injection of one type of a molten resin and hence, the structure of the injection molding apparatus can be simplified, leading to a remarkably reduced equipment cost, as compared with an injection molding apparatus arranged to accommodate the injection of two type of molten resins used for forming the primary molding and the secondary molding.
A graph in FIG. 10 shows the measured roundness in inside diameter of the main section 2 , when the throttle body 1 has been formed by the process of the present invention (i.e., the process for forming the main section 2 and the subsidiary section 3 in the primary molding and the secondary molding), and the measured roundness in inside diameter of the main section 2 , when the throttle body 1 has been formed by the conventionally known process (i.e., the process for forming the main section 2 and the subsidiary section 3 at a single molding step). The roundness represents a maximum value of an error to the roundness in inside diameter of the main section 2 of the throttle body 1 . As the value is smaller, the accuracy is higher, and as the value is larger, the accuracy is lower.
The roundness was measured when the throttle body 1 was formed using various materials which are a general-purpose engineering plastic and a super engineering plastic. Results are given in FIG. 10, which were provided when the throttle body 1 was formed using three of these resin materials, i.e., a polyamide (PA)-based resin, a polybutylene terephthalate (PBT)-based resin and a polyether imide (PEI)-based resin. The term “there is no difference in die temperature” indicates a case where the temperature of the entire die was maintained constant, wherein such temperature was determined depending on the type of the resin. The term “there is a difference in die temperature” indicates a case where the temperature (the internal temperature )of a portion of the die facing the inner peripheral surface of the main section 2 of the throttle body 1 was maintained lower than the temperature (the external temperature) in the other portion of the die, wherein such temperature was determined depending on the type of the resin. The temperature of the die can be controlled by the flow rate of cooling water flowing within the die.
As apparent from FIG. 10, in both of cases of “there is no difference in die temperature” and “there a difference in die temperature”, the accuracy was lower when the conventional single molding step was carried out, whereas in the present embodiment, the accuracy was slightly reduced as the primary molding and the secondary molding were carried out, but the accuracy of the final secondary molded product was far increased, as compared with the product formed at the conventional single molding step. In addition, the influence exerted by the resin material is as follows: When PA which is an extremely inexpensive general-purpose engineering plastic was used, the accuracy was lower, and when PBT which is a relatively expensive general-purpose engineering plastic was used, the accuracy was considerably high. When PEI which is an expensive super engineering plastic was used, the accuracy was highest.
Further, in the case of “there is a difference in die temperature”, the accuracy was increased indiscriminately, as compared with the case of “there is no difference in die temperature”. The reason is that the inner peripheral surface of the main section 2 of the throttle body 1 requiring the dimensional accuracy can be cooled more early than the other portions by setting the temperature of the movable core 23 for forming the inner peripheral surface of the main section 2 of the throttle body 1 at a level lower than that of the other portions, thereby preventing the generation of a shrinkage.
If a super engineering plastic (e.g., a polyether imide (PEI), a polyether sulfone (PES), a polyphenylene sulfide (PPS), a polyamideimide (PAI) or the like) is used for forming the throttle body 1 in an injection molding manner, it is extremely effective for ensuring the accuracy, but a problem of an increased cost is arisen. On the other hand, if a general-purpose engineering plastic (e.g., a polyamide (PA), a polyacetal (POM), a polybutylene terephthalate (PBT) or the like) is used in place of the super engineering plastic, the dimensional accuracy is slightly degraded, but the cost can be reduced.
Therefore, any of the specification having a preference of the dimensional accuracy and the specification having a preference of the cost can be selected freely by using the same type of super engineering plastics are used at the primary and secondary molding steps, when the dimensional accuracy is important, and using the same type of general-purpose engineering plastics are used at the primary and secondary molding steps, when the dimensional accuracy is not so important.
Different types of resin materials may be used at the primary and secondary molding steps, respectively. More specifically, if a super engineering plastic such as a polyether imide or the like is used at the primary molding step at which a dimensional accuracy is required, and an inexpensive general-purpose engineering plastic such as a polyamide (PA) or the like is used at the secondary molding step at which a dimensional accuracy is less required, the reduction in cost can be provided.
A second embodiment of the present invention will now be described with reference to FIGS. 11A and 11B.
In the above-described first embodiment, the molten resin has been poured with a time lag into the primary molding die D 1 and the secondary molding die D 2 . In the second embodiment, however, a molten resin is poured simultaneously into the primary molding die D 1 and the secondary molding die D 2 , whereby the producing efficiency can be enhanced. For this purpose, the movable plate 12 can be rotated intermittently by 180° about an axis L, and two movable cores 23 1 , 23 1 are mounted on the movable plate 12 . The structure of the stationary plate 11 is substantially the same as in the first embodiment, but the switch-over valve 38 is not mounted, because the molten resin is poured simultaneously into the primary molding die D 1 and the secondary molding die D 2 .
Thus, a primary molding is carried out in the primary molding die D 1 and a secondary molding is carried out in the secondary molding die D 2 by supplying the molten resin simultaneously into both the dies D 1 and D 2 in a state in which the primary molding die D 1 is unoccupied, and the formed main section 2 has been set in the secondary molding die D 2 , as shown in FIG. 11 A.
Then, the die-opening is carried out, as shown in FIG. 11 B. The completed throttle body 1 is withdrawn from the secondary molding die D 2 , and the movable core 23 1 and the main section 2 are moved to the secondary molding die D 2 , as shown in FIG. 11C, by rotating the movable plate 12 through 180°. The die-clamping is carried out, as shown in FIG. 11 D and then, the molten resin is supplied simultaneously into both the dies D 1 and D 2 , as shown in FIG. 11E, returning to the state shown in FIG. 11 A.
According to the present embodiment, one throttle body 1 can be formed in one run of the injection of the molten resin, leading to a remarkably increased production efficiency.
A third embodiment of the present invention will now be described with reference to FIGS. 12A and 12B.
In the third embodiment, the size of the main section 2 of the throttle body 1 is reduced as much as possible and limited in a range corresponding to the outer periphery of the throttle valve 5 , and the size of the remaining subsidiary section 2 is increased. It is extremely effective for ensuring the accuracy to use a super engineering plastic (e.g., a polyether imide (PEI), a polyether sulfone (PES), a polyphenylene sulfide (PPS), a polyamideimide (PAI) or the like), particularly, a polyether imide (PEI) as a resin material, but it is a drawback that such an engineering plastic is highly expensive. Therefore, the ensuring of the dimensional accuracy and the reduction in cost can be reconciled by using a super engineering plastic, particularly, a polyether imide for the main section 2 requiring a high dimensional accuracy and reduced in size, and using a general-purpose engineering plastic (e.g., a polyamide (PA), a polyacetal (POM), a polybutylene terephthalate (PBT) or the like), particularly, an inexpensive polyamide (PA) for the remaining subsidiary section 3 which does not require the dimensional accuracy.
Although the embodiments of the present invention have been described in detail, it will be understood that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit and scope of the invention defined in claims.
For example, the primary molding die may be placed into the secondary molding die, whereby the primary and secondary molding steps may be carried out in the same die.
|
A process produces a resin intake member by injection moling. The intake member has a hollow generally cylindrical main section and a subsidiary section integrally connected to an outer periphery of the hollow main section. The process includes a primary molding step which forms the hollow main section in a primary molding die and a secondary molding step which subsequently inserts the formed hollow main section into a secondary molding die to integrally form the subsidiary section with the hollow main section in the secondary molding die.
| 1
|
TECHNICAL FIELD
The present invention relates to a mesh fabric useful for a printing screen which consists essentially of conjugate filaments.
BACKGROUND OF THE INVENTION
In the past, as fabrics for printing screens, silk or stainless-steel mesh fabrics have been broadly used. However, the silk mesh fabrics were deficient in the strength and the dimensional stability for a printing screen. As regards the stainless steel mesh fabrics, severe problems were found in the elastic recovery and the instantaneous repelling force when a squeegee was applied. Further, silk and stainless are expensive.
Recently, for the above reasons, polyester or nylon mesh fabrics have been more used for printing screens. Particularly, the polyester mesh fabrics have been more preferred from the viewpoint of the high dimensional stability. However, the polyester mesh fabrics have the following disadvantages:
(a) White-powdery scum is generated during the weaving, which will cause many troubles.
(b) The emulsion-coating properties is low.
(c) For forming a coating film at a constant thickness, skillful techniques and several overlap coatings are required.
(d) The production efficiency is low.
(e) The adhesion of the meshes to an emulsion resin is insufficient. The printing durability is low.
In attempt to solve the above problems, various ways utilizing chemical treatment with acids or alkalies or the like, flame treatment, corona-discharge treatment, and so forth have been examined. However, various troubles such as reduction in the strength of the material and so forth have arised. The test results of the screens prepared in such ways have been unsatisfactory for practical application.
On the other hand, with diversification in the printing fields, high printing precision and high printing durability have been more required. Particularly, it is needed to develop a screen which has a high dimensional stability comparable to that of a stainless-steel screen, a high adhesion to an emulsion resin comparable to that of a nylon screen, and a high elastic recover property comparable to that of a polyester screen.
Japanese Laid-Open Patent Publication No. 142,688 of 1984 discloses an anti-static mesh fabric made from conjugate filaments. The anti-static mesh fabric is characteristic in that it is made from a theremoplastic synthetic polymer added with electro-conductive carbon black. An object of that lies in an improvement in the antistatic property of a screen mesh fabric. However, there is not taught any way for improvement of printing precision and printing durability which have been much desired as described above.
Accordingly, an object of this invention is to provide a mesh fabric useful for a printing screen having high dimensional stability, adhesion to an emulsion resin and elastic recovery property, that is, having high printing precision and printing durability.
DISCLOSURE OF THE INVENTION
In accordance with the invention, the mesh fabric consists essentially of conjugate filaments each composed of a sheath and a core. The material of the sheath has a high adhesive property to an emulsion and a resin of the screen, and the material of the core has a high dimensional stability and an elastic recovery property. The mesh fabric has a breaking elongation X (%) of from 15 to 40% and a breaking strength Y (kg·f) of not less than 25 kgf by the labelled strip measurement method at the specimen width of 5 cm and the grip interval of 20 cm, said breaking elongation X (%) and said breaking strength Y (kg·f) satisfying following formula: Y≧(X+1)×5/3, in the range of the elongation of not less than 5%.
The desired end of this invention can be achieved by using different synthetic fibre materials as a conjugate filament to act usefully whereby the composite filament can be provided only the good properties of each materials.
As the material of the core, polyesters, polyolefins or the like having a high dimensional stability and an elastic recovery property are used to afford screens having high dimensional stability. As the material of the sheath, polyamides, low viscosity type polyesters or the like having a high adhesive property to resins are used to present generating white-powdery scum as often found during the weaving of conventional polyester screens and to afford screens having high strength and emulsion-coating properties and ink-squeezing properties.
Accordingly, the mesh fabric of the invention can always be produced with high efficiency and can be used to produce printing screens having high printing precision and printing durability.
As understood from the preceding, the present mesh fabric is so designed as to have the strength and the elongation within the above-described range, typically by selecting materials for the conjugate filament and heat-setting the mesh fabric, whereby the workability of the mesh fabric during the stretching stage for producing a screen, the dimensional stability of the screen, and the high-tension printing durability of the screen during the printing stage are remarkably enhanced, which enables the present mesh fabric to be applied for high precision printing.
One of the characteristics of the present mesh fabric lies in that it has such an appropriate breaking elongation for a printing screen as is unobtainable with conventional stainless-steel mesh fabrics, and the breaking strength considerably higher than that of conventional synthetic fibre mesh fabrics, and has such a low elongation and a high strength that the stress-strain curve satisfies the formula Y≧(X+1)×5/3 where Y designates the strength (kg·f) and X the elongation (%), in the range of the elongation of not less than 5%. Accordingly, the present mesh fabric is applicable for producing a printing screen having a small elongation at a high tension. Typically, the present mesh fabric affords to produce a high-tension printing screen having a tension of not more than 0.6 by measurement with a Type 75 B tension gauge (made by Sun Giken), which is unobtainable with conventional synthetic fibre mesh fabrics, with high workability.
Polyester or polyolefin which constitutes the core of the conjugate filament used in the invention must be a material of which the viscosity at a spinning temperature depending of the type of the material is appropriate for the spinning.
As the polyester, there may be used polyalkyleneterephthalate, polyalkylene-telephthalate copolymer, poly[1,4-cyclohexanediol.terephthalate] and the like. From the viewpoint of the high dimensional stability of the mesh fabric needed for the heat-setting in the processing stage after the weaving, polyethyleneterephthalate, polybutyleneterephthalate, and poly [1,4-cyclohexanediol.terephthalate] are preferable. Polyethyleneterephthalate is most preferred from the economical viewpoint.
As the polyolefins, there may be used polyethylene, polypropylene, polybutene-1 and the like. Polyethylene and polypropylen are preferable, because of the high stability during the spinning and the easy handling. Polypropylene, which is effective in a relatively wide range of the spinning temperature, is most preferable.
On the other hand, as the polyamides constituting the sheath of the conjugate filament, there may be used aliphatic polyamides such as 6-nylon, 6,6-nylon, 6,10-nylon, nylon 12, condensation polyamides of para-aminocyclohexylmethane and dodecanedioic acid; and aromatic polyamides such as polyxylyleneadipamide, polyhexyamethylenephthalamide and the like. 6-nylon and 6,10-nylon are preferably used from the economical viewpoint and for the easy spinning.
As regards the constitution of the conjugate filament, it is important that the sheath is continuously present in the whole periphery of the conjugate filament without the core exposed to the surface. The conjugate filament may be circular in the section. Particular restrictions are not imposed on the arrangement and shape of the core. The core may be single- or multi-core, circular or profile in the section, and concentric or eccentric. From the viewpoint of the dimensional stability, it is preferred that the filament contains concentrically a single-core with a circular section, or contains a type of multi-cores each having a circular section, since such arrangement and shape prevents effectively an applied stress from being distributed in the filament.
Preferably, the volume ratio of core to sheath is in the range of from 1:5 to 3:1, and more preferably in the range from 1:2 to 2:1. If the volume ratio of core to sheath is inadequately high, the sheath film is relatively thin, so that irregularities in the thickness of the film will occur during the spinning and cause breakage of the film, which leads to breakage of the film when it undergoes an external stress during the weaving, the mesh fabric stretching on frame, or the printing. If the volume ratio of the core to the sheath is inadequately small, the conjugate filament will have an insufficient resistance to tensile stress, which brings a deficiency in the dimensional stability to the screen.
The conjugate filament is applicable in form of a monofilament or a multi-filament in this invention. For the purpose of obtaining a screen having high printing precision, the conjugate filament in form of a monofilament is generally preferred. The size of the filament is preferably not less than 1 denier, and more preferably in the range of from 5 to 50 deniers. The preferable diameter of the filament is not more than 100 μm.
For weaving, the conjugate filament is generally used as a drawn yarn. For ensuring the dimensional stability of the screen, the drawing ratio and the heat set temperature is set so that the strength of the drawn filament is not less than 5.5 g/d, and the residual elongation is in the range of from 30% to 50%, and the heat shrinkage is not more than 10%. Preferably, the drawn yarn has a strength of not less than 6 g/d, the residual elongation of from 35% to 45%, and a boiling water shrinkage of not more than 9%.
In general, the density of the mesh fabric is in the range of from 10 to 600 per inch (that is, 100-600 mesh plain weave). Depending on the nature of the screen, that is, the supply amount of printing ink, the line width of pattern and so forth, an adequate density needs to be selected. A preferred density is in the range of from 100 to 350 per inch.
The raw fabric obtained by weaving the conjugate filaments is washed with an aqueous solution of a nonionic or anionic surface active agent, and heat-set at a temperature of from 100° C. to 190° C. with a tension of from 100 to 250 kg to obtain the desired thickness and mesh number.
After the heat-setting, the mesh fabric is cleaned in the surface, dried and subjected to the stretching stage for fixing the mesh fabric to the frame of a screen. The present mesh fabric may be applied for any frame of aluminum, iron, wood and resin.
The mesh fabric of the invention, obtained from the above-mentioned conjugate filaments, undergoes substantially no changes in the quality with the lapse of time. Accordingly, the mesh fabric is applicable to the following coating stage using a photosensitive or heat-sensitive resin emulsion after being left for 24 hours from being fixed on the frame as mentioned above. Using the mesh fabric, the workability for producing a screen stencil can be remarkably improved.
On the other hand, the conventional nylon mesh fabrics, when stretched on the frame of a screen, suffer significant changes in the quality with the lapse of time, and are unsuitable for precision screen printing. Also, conventional polyester mesh fabrics need to be left as they are for more than 72 hours from the stretching stage, because of the large change in the quality with the lapse of time.
For producing a screen stencil, commercially available photosensitive or heat sensitive resin emulsions are applicable to the mesh fabric of the invention. As the photosensitive agent, dichromates such as ammonium dichromate and the like, diazo compounds are applicable. As the emulsion resin, gelatin, gum arabic, vinylalcohol, vinylacetate, acrylic resin and mixtures thereof are applicable. Additives such as an emulsifier, an anti-static agent and the like may be added in the emulsion.
Although the coating thickness of an emulsion applied to the mesh fabric will be varied, depending on the desired nature of the screen, the mesh fabric according to the invention, the surface of which is covered with apolyamide having high adhesive property to the emulsion to be applied, is significantly improved in the emulsion coating property, as compared with conventional polyester mesh fabrics, so that a resin layer uniform in the thickness can be easilly formed thereon.
In the ordinary way, an emulsion is applied to the mesh fabric to a predetermined thickness, dried and then exposed to light or heated for obtaining a screen stencil. For curing the resin in a pattern, generally, high voltage mercury lamps, xenon lamps (about 4 kw) are used as the light source. The distance between the light source and the screen is in the range of from 1 to 1.5 m, and the exposure time is in the range of from 2 to 5 minutes. The integrated quantity of light is in the range of from 300 to 500 milli-jules/cm 2 .
The screen stencil obtained with the mesh fabric of the invention as described above is improved in the dimensional stability and the elastic recovery property, and has high printing precision and printing durability. For preventing blurring or fogging of the pattern formed on the screen which is caused by halation when the screen is exposed to light according to the process, it is preferred that the conjugate filament is treated in such a manner that at least the surface of the core of the conjugate filament is rendered light-absorptive to the exposure light during the process.
The above-mentioned light-absorptive property may be given by dyeing the mesh fabric after the weaving by dope-coloring the sheath material of the conjugated filament with pigments or dyes or by incorporating a ultra-violet ray absorbing agent in the sheath material of the conjugate filament.
The mesh fabrics obtained from conventional polyester filaments need to be high-pressure dyed for the dyeing, accompanied with low production efficiency. Further, the mesh fabrics are ready to undergo heat shrinking during the high-pressure dyeing and having foreign matters adhere to the surface thereof. Accordingly, the conventional mesh fabrics are unsuitable for producing a printing screen having a fine pattern with high efficiency.
However, according to the invention, since the conjugate filament in which the sheath is a polyamide having a good dyeing property can be used, the filament can be dyed under the ordinary pressure. Accordingly, the mesh fabric according to the invention can be rendered halation-preventive to the exposure light in the photometrical process, without substantial shrinking of the fabric and without substantial foreign materials adhered to the surface during the dyeing process.
Further, in the invention, a pigment or an ultraviolet ray absorbing agent may be incorporated in the sheath material of the conjugate filament to obtain the mesh fabric having a stable halation-preventive property without dyeing. In this case, since the desired effect can be obtained by incorporating the pigment or the like only in the sheath material of the conjugate filament, there can be very economically produced a screen stencil having good halation-preventive property without heat-shrinking of the mesh fabric and without foreign materials adhered to the surface of the filament. Accordingly, screen stencils having fine patterns with high density can be precisely produced.
Generally, the wavelength of the light employed in the photometrical process has a peak within the range of 280 to 450 nm. It is preferred that the conjugate filament is treated in such a manner as to have a light absorptive property to the light within the wavelength range of 280 to 450 nm, depending on the light employed in the photometrical process.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates, in graphical comparison, the stress-strain curves of a mesh fabric with the mesh size of 150 made of conjugate monofilaments (fibre diameter: 48 μm) according to the invention and a mesh fabric with the mesh size of 150 made of polyester filaments (fibre diameter: 48 μm).
FIG. 2 illustrates, in graphical comparison, the stress-strain curves of a mesh fabric with the mesh size of 200 made of conjugate monofilaments (fibre diameter: 48 μm) according to the invention and a mesh fabric with the mesh size of 200 made of polyester filaments (fibre diameter: 48 μm).
FIG. 3 illustrates, in graphical comparison, the stress-strain curves of a mesh fabric with the mesh size of 250 made of conjugate monofilaments (fibre diameter: 40 μm) according to the invention and a mesh fabric with the mesh size of 250 made of polyester filaments (fibre diameter: 40 μm).
FIG. 4 illustrates, in graphical comparison, the stress-strain curves of a mesh fabric with the mesh size of 270 made of conjugate monofilaments (fibre diameter: 34 μm) according to the invention and a mesh fabric with the mesh size of 270 made of polyester filaments (fibre diameter: 34 μm).
FIG. 5 illustrates, in graphical comparison, the stress-strain curves of a mesh fabric with the mesh size of 300 made of conjugate monofilaments (fibre diameter: 34 μm) according to the invention and a mesh fabric with the mesh size of 300 made of polyester filaments (fibre diameter: 34 μm).
FIG. 6 illustrates graphically a correlation between the load and the deformation of the fibres.
FIG. 7 shows a microscope photograph (magnification: 500) of a mesh fabric with the mesh size of 250 made of dope-dyed conjugate monofilaments.
FIG. 8 shows a microscope photograph (magnification: 500) of a dyed mesh fabric with the mesh size of 250 made of conjugate monofilaments.
FIG. 9 shows a microscope photograph (magnification: 500) of a dyed mesh fabric with the mesh size of 250 made of polyester monofilaments.
FIG. 10 shows a microscope photograph (magnification: 500) of a printing screen produced by processing a mesh fabric with the mesh size of 300 made of dope-dyed conjugate monofilaments.
FIG. 11 shows a microscope photograph magnification: 500) of a printing screen produced by processing a dyed mesh fabric with the mesh size of 300 made of conjugate monofilaments.
FIG. 12 shows a microscope photograph (magnification: 500) of a printing screen produced by processing a dyed mesh fabric with the mesh size of 300 made of polyester monofilaments.
FIG. 13 shows a microscope photograph (magnification 500) of a printing screen produced by processing an uncolored mesh fabric with the mesh size of 300 made of conjugate monofilaments.
FIG. 14 shows a microscope photograph (magnification: 500) of a printing screen produced by processing an uncolored mesh fabric with the mesh size of 300 made of conjugate monofilaments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be illustrated by way of the following examples which are for the purpose of illustration only and are in no way to be considered as limiting.
Example 1
Circular-section concentric conjugate filaments comprising a 6 nylon sheath and a polyethyleneterephthalate core in the volume ratio of sheath to core of 1:1 were prepared at the spinning temperature of 285° C. and the winding speed of 1,000 m/min., and drawn to the draw ratio of 3.90 at the drawing temperature of 84° C. and the orientation set temperature of 180° C., so that three types of conjugate filaments with the fibre diameter of 48 μm, 40 μm and 34 μm were obtained.
Five types of mesh fabrics as listed in Table 1 were prepared from the conjugate filaments. After heat-setting the fabrics, the strength and elongation were measured. Table 1 lists the measurement results in comparison with the measurements of polyester mesh fabrics having the same fibre diameter and mesh size as those of the mesh fabrics of the composite filaments, respectively.
TABLE 1______________________________________ Aver- age Average elonga-Types of fabrics strength tionNo. Mesh Fibre materials (kgf) (%)______________________________________A1 150 conjugate monofilament 48 μm 40.0 31.7B1 150 polyester monofilament 48 μm 28.0 26.0A2 200 conjugate monofilament 48 μm 51.0 33.7B2 200 polyester monofilament 48 μm 38.0 29.0A3 250 conjugate monofilament 40 μm 43.8 33.6B3 250 polyester monofilament 40 μm 33.8 28.0A4 270 conjugate monofilament 34 μm 37.9 34.3B4 270 polyester monofilament 34 μm 28.3 28.5A5 300 conjugate monofilament 34 μm 40.4 35.9B5 300 polyester monofilament 34 μm 29.2 29.2Test Method according to the labelled strip method of JIS L 1068 (1964)Testing Machine: constant-speed tension tester (prepared by Shimadzu Corporation, Type-500)Test Conditions: 20° C., 65% R.H. environments specimen width of 5 cm, specimen grip- distance of 20 cm, tension speed of 10 cm/min.Number of Experi- 50mental Times:______________________________________
FIGS. 1 to 5 show the stress-strain curves of the mesh fabrics A1 to A5 and B2 to B5 as listed in Table 1, and conventional nylon mesh fabrics C1 to C5. The test conditions were the same as above-described. The materials and the mesh size of the mesh fabrics C1 to C5 were as follows
C1: 150 mesh fabric made of nylon monofilaments of 50 μm fibre diameter
C2: 200 mesh fabric made of nylon monofilaments of 50 μm fibre diameter.
C3: 250 mesh fabric made of nylon monofilaments of 39 μm fibre diameter
C4: 270 mesh fabric made of nylon monofilaments of 39 μm fibre diameter
C5: 300 mesh fabric made of nylon monofilaments of 39 μm fibre diameter
As understood from Table 1, and FIGS. 1 to 5, the mesh fabrics A1 to A5 have a moderate elongation and a very high strength as compared with that of the conventional screen materials B1 to B5 and C1 to C5. Also, the mesh fabrics A1 to A5 according to the invention satisfy the formula Y≧(X+1)×5/3 when the elongation Y (%) is not less than 5%, with respect to the stress-strain curve. On the contrary, the conventional screen materials B1 to B5 and C1 to C5 exhibit a stress-strain curve where the gradient is relatively small, and the elongation is far from satisfying the above formula.
Table 2 tabulates the generation state of white-powdery scum of the fabrics A2, B2, A3, B3, A5 and B5, as listed in Table 1, during the weaving.
The fabrics A2 and B2 were 200 mesh fabrics woven with 18,800 warps at the weft filling rate of 230 times/min.
The fabrics A3 and B3 were 250 mesh fabrics woven with 23,500 warps at the weft filling rate of 230 times/min.
The fabrics A5 and B5 were 300 mesh fabrics woven with 28,200 warps at the weft filling speed of 210 times/min.
All the fabrics were woven by means of a Sulzer weaving machine. During weaving, when the scum was considerably generated, air was sprayed on the reed with an airgun to remove the scum.
TABLE 2______________________________________ White-powdery Opera- scum tion ReedType of fabrics rate cleaning Evalua- No. Fibre materials % (m/time) tion______________________________________A2 conjugate monofilament 96 5,000 ⊚B2 polyester monofilament 91 300 ○A3 conjugate monofilament 97 4,500 ⊚B3 polyester monofilament 92 180 ΔA5 conjugate monofilament 98 3,000 ⊚B5 polyester monofilament 90 140 X______________________________________ Evaluation ⊚ White-powdery scum is scarcely generated. ○ : The remaining ratio of whitepowdery scum is up to 20%.? Δ: The remaining ratio of whitepowdery scum is more tha 20% up to 50%.? X: The remaining ratio of whitepowdery scum is more than 50%.
The test results of Table 2 indicate that the fabrics A2, A3 and A5 according to the invention could be so woven as to superior qualities substantially without generation of white-powdery scum.
Example 2
The mesh fabrics as described in Example 1 were heat-set, and fixed to an aluminum frame with a screen stretching machine. During the procedure, the compressor pressure of the screen stretching machine was measured with changing the tension of the mesh fabrics. At the same time, the elongation of the mesh fabrics was examined by marking at a 50 cm distance in the center of the mesh fabrics in both of warp and weft directions and measuring the changes of the distance.
Table 3 shows the relation of the tension of the mesh fabrics to the compressor pressure of the screen stretching machine and further the elongation of the mesh fabrics. Table 4 shows the changes of the tension of the mesh fabrics with the lapse of time. The symbols A2, A3, A5, B2, B3 and B5 designate the same mesh fabrics as described in Example 1, respectively.
The used test apparatus were as follows:
______________________________________Screen stretching 3 S Air Stretcher manufactured bymachine: Mino GroupAluminum frame: 880 mm × 880 mm frame width of 40 mm, frame thickness of 25 mmTension meter: Type 75 B Tension Gauge manufactured by Sun Giken______________________________________
TABLE 3______________________________________Compressor pressure(kg/cm.sup.2) Elongation (%) conjugate conjugateTension monofilament polyester monofilament polyester(mm) fabrics fabrics fabrics fabrics______________________________________ A2 B2 A2 B21.00 6.2 6.5 3.4 6.10.90 6.8 7.3 4.4 7.60.80 7.2 8.0 5.2 9.60.70 8.5 9.5 6.2 11.80.60 9.0 rupture 6.6 rupture A3 B3 A3 B31.00 6.0 6.5 4.6 7.30.90 6.8 7.0 5.2 9.60.80 7.3 8.3 6.2 10.40.70 8.3 9.0 7.6 12.70.60 9.0 rupture 8.8 rupture A5 B5 A5 B51.00 6.2 6.8 5.0 8.30.90 7.0 8.0 5.8 10.50.80 8.0 8.6 7.2 12.50.70 8.5 rupture 8.4 rupture0.60 9.5 -- 9.0 --______________________________________
TABLE 4______________________________________Changes of tension (mm) conjugateTime monofilament polyester nylon(hr) fabrics (A2) fabrics (B2) fabrics (C2)______________________________________ 0 1.00 1.00 1.00 6 1.02 1.03 1.0412 1.03 1.05 1.0724 1.03 1.06 1.0948 1.03 1.07 1.1172 1.03 1.07 1.1296 1.03 1.08 1.13120 1.03 1.07 1.14144 1.03 1.08 1.15168 1.03 1.08 1.16______________________________________
The test results in Tables 3 and 4 indicate that the mesh fabrics A2, A3 and A5 can be stretched to form a screen by application of a high tension with high workability and stability. On the contrary, in the case of the conventional polyester mesh fabrics B2, B3 and B5, the elongation is accerately increased as the tension becomes higher. The conventional mesh fabrics are difficult to be stretched with stability for formation of the screen. The conventional mesh fabrics have limitations to the application of tension. As to the change of the tension after stretching, the conventional mesh fabrics of polyester (B2) and nylon (C2) exhibit significant changes. Particularly, the tension of the nylon mesh fabric C2 exhibits no constant value one week after stretching.
Example 3
The tribo-electrification voltage, the half-life, and the leak resistance of the present mesh fabrics were measured, and compared with those of a conventional polyester mesh fabric, a low-temperature plasma-treated polyester mesh fabric, and an anti-static treated polyester mesh fabric. Table 5 shows the measurement results.
The test method is as follows:
Tribo-electrification voltage: measured by Kyodai Kaken Type Rotary Stick Tester(manufactured by Koa Syokai).
Cloth to be rubbed against the mesh fabrics--cotton shirting Number 3
revolution speed--450 rpm
load--500 g
friction time--60 sec.
Leak resistance: measured by SM-5 ultra-insulation resistance tester (manufactured by ToaDenpa Kogyo) at the temperature of 20° C. and the RH of 40% according to JIS G-1026.
TABLE 5______________________________________ tribo-electri- leak fication half-life resist-type of fabrics voltage (V) (sec) ance (Ω)______________________________________conjugate monofilaments 480 2 2 × 10.sup.9fabricuntreated polyester 5,200 60< 2 × 10.sup.13fabricplasma-treated polyester 6,200 60< 2 × 10.sup.13fabricanti-static treated 540 2 3 × 10.sup.10polyester fabric______________________________________
The test results indicate that the fabric according to the invention causes no troubles by static electricity in printing process, and is useful as a printing screen.
Example 4
The mesh fabrics as listed in Table 1 of Example 1 were washed with a 0.2% neutral detergent aqueous solution, and dried. On each mesh fabric, a PVA-vinylacetate type photosensitive emulsion NK-1 (manufactured by Carley Co., Ltd., West Germany) was coated and dried to form a photosensitive coating film of 10 to 12 μm. Then, the photosensitive coating film was printed in the following cross stripes patterns which had different sizes regularly varied in ten steps.
______________________________________No. size of cross stripes row line number of crosses______________________________________1 0.1 mm × 0.1 mm 20 10 2002 0.2 mm × 0.2 mm 20 10 2003 0.3 mm × 0.3 mm 20 10 2004 0.4 mm × 0.4 mm 20 10 2005 0.5 mm × 0.5 mm 20 10 2006 0.6 mm × 0.6 mm 20 10 2007 0.7 mm × 0.7 mm 10 10 1000 0.8 mm × 0.8 mm 10 10 1009 0.9 mm × 0.9 mm 10 10 10010 1.0 mm × 1.0 mm 10 10 100______________________________________
The printing was carried out by using a 4 kw rated high voltage mercury lamp. The distance between the coating film and the mercury lamp was 1.5 meters, and the exposition time interval was 3 minutes. The integrated quantity of light was 400 milli jules/cm 2 .
Followingly, the mesh fabrics having the coating film was dipped in water for 3 min., and was sprayed with water so that the unexposed part of the coating film was removed.
Each mesh fabric having the different cross patterns was subjected to a tape peeling test for measurement of the bonding strength of the cured cross patterns of the photosensitive resin.
Method for Tape Peeling Test
Filament tape #810 made by Sumitomo 3 M Co., Ltd. was adhered on the cross patterns formed on each mesh fabric Thereafter, the tape was peeled off from the mesh fabric. The procedure was repeated three times for the same surface. The number of patterns adhered to the tape were counted.
Table 6 shows the test results. In the table, the numerical values in the column with the heading "first" represent the number of patterns peeled from the mesh fabric by the first tape adhesion. The numerical values in the columns with the headings "second" and "third" represent the total number of peeled patterns after the second and the third tape adhesion, respectively.
TABLE 6______________________________________number of cross-size numberpeeled patterns 1 2 3 4 5 6 7 8 9 10______________________________________firstA2 4 0 0 0 0 0 0 0 0 0B2 16 4 2 2 1 0 0 0 0 0secondA2 4 1 0 0 0 0 0 0 0 0B2 26 4 4 2 2 1 0 0 0 0thirdA2 4 2 0 0 0 0 0 0 0 0B2 48 20 8 6 6 4 1 0 0 0firstA3 2 0 1 0 0 0 0 0 0 0B3 14 8 2 4 1 0 0 0 0 0secondA3 2 0 1 0 0 0 0 0 0 0B3 22 15 8 4 2 1 0 0 0 0thirdA3 2 1 1 0 0 0 0 0 0 0B3 40 17 10 6 4 2 0 0 0 0firstA4 2 0 0 0 0 0 0 0 0 0B4 15 8 2 2 0 1 0 0 0 0secondA4 2 0 0 0 0 0 0 0 0 0B4 24 9 7 5 0 1 1 0 0 0thirdA4 2 0 1 0 0 0 0 0 0 0B4 30 17 7 5 1 1 1 0 0 0firstA5 4 0 0 0 0 0 0 0 0 0B5 16 9 10 2 0 0 0 0 0 0secondA5 4 0 0 0 0 0 0 0 0 0B5 18 11 10 2 1 0 0 0 0 0thirdA5 4 1 0 0 0 0 0 0 0 0B5 33 11 10 2 2 1 0 0 0 0______________________________________
The symbols A2 to A5 and B2 to B5 designate the same mesh fabrics as listed in Table 1 of Example 1, respectively.
Example 5
After heat-setting of the mesh fabrics as listed in Table 1 of Example 1, E.P.C. and the tensile modulus of elasticity of the fabrics were measured, and compared with those of conventional polyester mesh fabrics. The results are shown in Table 7 and Table 8.
E.P.C.
It represents the physical properties of fibres as Elastic Performance Coefficients, which involve the recovery properties of the fibres after the subjection to mechanical action.
The correlations between the load and deformation of a fibre at the first and the n-th cycle of the load and deformation test are illustrated in such a manner as shown in FIG. 6.
In the figure, the symbols represent the following:
L o : load and deformation curve of a fibre at the first cycle of the test,
L c : load and deformation curve of the fibre at the conditioning,
R o : recovery curve of the fibre at the first cycle of the test,
R c : recovery curve of the fibre at the conditioning,
a o : deformation of the fibre by loading at the first cycle, and
a c : deformation of the fibre by loading at the conditioning
The symbol A such as A in AL o and so forth designates an energy value required for the deformation or the recovery of the fibre.
The ratio of AR o to Al o indicates the degree of recovery-performance of the fibre at the conditioning, and is a linear function of the tension speed.
a o 2 /AL o indicates the degree of energy absorption to the deformation generated at the first cycle.
a c 2 /AL c indicates the degree of energy absorption to the deformation energy at the conditioning.
Accordingly, E.P.C. is expressed by the following equation using these ratios and the correction item AR o /AL o . ##EQU1## In case that the fibre can be recovered: AR o =AL o , a o =a c , AL o =AL c , AR o =AR e , E.P.C.=1
In case that the fibre cannot be recovered: AR=0, AR c =AL c , a c =a o , E.P.C.=0
[See "TEXTILE PHYSICS" Maurzen, p. 254-255 (1979)]
Tensile Modulus of Elasticity
This test method is in accordance with JIS L 1096.
An automatic recorder equipped, constant speed tensile tester is used. The distance between the grips for a specimen is 20 cm. The tension speed is a rate of 10% of the grip distance per 1 minutes. The specimen is stretched till a predetermined load is obtained. Successively, the specimen is unloaded at the same speed as that at loading. Then, the specimen is stretched at the same speed till the predetermined load is obtained. The residual elongation is measured from the recorded load-elongation curves. The tensile modulus of elasticity is calculated from the following equation: ##EQU2## where L is an elongation (mm) at a predetermined load, and L 1 is a residual elongation (mm) at the predetermined load.
E.P.C. and the tensile modulus of elasticity were measured under the following conditions:
Test Method: according to the labelled strip method of JIS L 1068 (1968)
Testing Machine: Constant-Speed Stretching Type tester (made by Shimadzu Corporation, Type S-500)
Test Conditions: temperature 20° C., R.H. 65% specimen width 5 cm, grip distance 20 cm tension speed 10 cm/min. cycle number 20
Experiment Times: 50
TABLE 7__________________________________________________________________________E.P.C. conjugate polyester conjugate polyester conjugate polyester conjugate polyester conjugate polyesterload monofilament fabric monofilament fabric monofilament fabric monofilament fabric monofilament fabric(kgf) fabric (A1) (B1) fabric (A2) (B2) fabric (A3) (B3) fabric (A4) (B4) fabric (B5)__________________________________________________________________________ 5 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.0010 0.98 0.79 1.00 0.90 1.00 0.93 0.97 0.75 1.00 0.8115 0.93 0.67 0.92 0.79 0.94 0.80 0.94 0.64 0.96 0.6920 0.86 0.55 0.85 0.61 0.88 0.70 0.88 0.52 0.90 0.5625 0.81 0.46 0.81 0.54 0.81 0.66 0.80 0.43 0.83 0.4830 0.73 0.74 0.45 0.75 0.44 0.73 0.7735 0.62 0.66 0.40 0.70 0.66 0.7040 0.51 0.59 0.65 0.64__________________________________________________________________________
TABLE 8__________________________________________________________________________Tensile Modulus of Elasticity conjugate polyester conjugate polyester conjugate polyester conjugate polyester conjugate polyesterload monofilament fabric monofilament fabric monofilament fabric monofilament fabric monofilament fabric(kgf) fabric (A1) (B1) fabric (A2) (B2) fabric (A3) (B3) fabric (A4) (B4) fabric (B5)__________________________________________________________________________ 5 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.010 99.1 89.8 100.0 93.3 100.0 95.0 98.3 94.0 100.0 94.115 96.8 82.0 97.7 86.9 98.6 87.3 95.7 87.5 97.9 88.020 93.3 70.0 93.2 79.4 92.5 74.5 91.1 80.9 93.5 76.025 88.6 65.3 88.8 68.2 89.2 68.5 88.4 68.8 88.0 64.030 82.7 82.2 60.1 82.6 60.2 83.6 83.235 75.9 74.6 51.8 75.5 75.9 76.140 70.0 69.9 70.3 70.4__________________________________________________________________________
The test results in Table 7 and Table 8 indicate that the mesh fabrics A1, A2, A3, A4 and A5 according to the present invention are excellent in the recovery property and undergo a less change at a higher load applied as compared with the conventional polyester fabrics B1, B2, B3, B4 and B5, and further have a high elastic recovery ratio and a high recoverability after subjected to mechanical action.
Accordingly, the present mesh fabrics have a durability remarkably improved as a printing screen and also high printing performances, which are attributed to the enhancement in the recovery property.
Example 6
The mesh fabrics as listed in Table 1 of Example 1 were heat-set, and fixed to an aluminum frame with a screen stretching machine, respectively. The stretched mesh fabrics were washed with water and dried. To each of the stretched mesh fabrics, a PVA-vinylacetate type photosensitive resin emulsion NK-14 manufactured by Carley Co., Ltd. was applied by lap-coating method, and dried. The thickness of the coating film was 12 μm. The photosensitive coating film formed on the mesh fabric was cured by exposure to light so as to have the following two patterns;
(1) a lattice-form pattern in which thin lines are crossed at a 150 mm interval to each other in the warp and the weft direction, and
(2) a pattern in which two groups of five thin lines of each of 50 μm, 60 μm, 80 μm, 100 μm, 125 μm, 150 μm, 200 μm, 250 μm and 300 μm wide in parallel at an equal distance are arranged.
The printing discrepancy is measured by using the pattern (1) at the number of printing times of 1,000 and 3,000. The reproducibility of thin line was measured by using the pattern (2).
The curing was conducted by means of a 3 kw rated metal halide lamp. The distance between the metal halide lamp and the coating film on the mesh fabric was 80 cm. The exposure time was 2 minutes. After the exposure, the mesh fabric was dipped in water for 3 minutes, and injected with water, so that the unexposed part of the coating film was removed.
As described above, the printing discrepancy and the thin line reproducibility of the mesh fabrics each having the cured pattern (1) or (2) were measured for evaluation of the printing precision of the mesh fabrics. Tables 9, 10 tabulate the test results.
Conditions for Producing Screen Stencil:
Screen stretching machine: 3S Air Stretcher (made by Mino Group, normal stretching type)
Tension: 1.00 mm (at completion of the stretching)
Emulsion: NK-14 (made by Carley Co., Ltd., West Germany)
Thickness of coating film: 12 μm
Frame: 880 mm×880 mm (made of aluminum)
Printing image: 300 mm×300 mm
Conditions of Squeegee:
Material: polyurethane
Hardness: 70°
Angle: 75°
Width: 405 cm
Printing Conditions:
Gap: 3.0 mm
Impression: 1.5 mm
Ink: UV ink 5104-T6 (made by Mitsui Toatsu Chemicals, Inc.)
Viscosity of ink: 200 PS
TABLE 9__________________________________________________________________________Printing Precision (μm) - Pattern (1)printingconjugate polyester conjugate polyester conjugate polyesterpositionmonofilament fabric monofilament fabric monofilament fabricnumberfabric (A2) (B2) fabric (A3) (B3) fabric (A5) (B5)of print1,000 3,000 1,000 3,000 1,000 3,000 1,000 3,000 1,000 3,000 1,000 3,000ing timestimes times times times times times times times times times times times__________________________________________________________________________1 39 55 95 138 43 54 108 146 35 50 115 1482 43 74 101 140 62 77 106 165 53 79 108 1703 58 81 120 164 55 74 124 169 70 81 127 1934 46 57 92 120 51 70 98 121 48 60 97 1305 66 85 108 142 74 86 107 168 55 80 104 1726 70 78 106 159 57 85 96 155 66 82 99 1687 46 67 100 126 36 51 98 133 36 64 101 1418 54 70 99 151 58 73 100 170 46 73 94 1659 73 91 114 161 69 73 124 172 69 77 130 185__________________________________________________________________________
TABLE 10______________________________________Thin Line Printing Resolution Propertiesconjugatemonofilament polyesterfabric fabric______________________________________A2 100 μm B2 150 μmA3 80 μm B3 150 μmA5 60 μm B5 125 μm______________________________________
As shown in Table 9 and Table 10, the mesh fabrics A2, A3 and A5 according to the invention have high printing precision and thin-line printing resolution property, and are advantageously applicable for high-density, high-precision printing.
On the contrary, the conventional polyester mesh fabrics B2, B3 and B5 were inferior in the thin-line printing resolution property. As the number of printing times was increased, the printing precision was remarkably reduced.
Example 7
E.P.C. and the tensile modulus of elasticity of the mesh fabrics after the 3,000 times screen printing as shown in Table 9 of Example 6 were measured, and compared with those of the conventional polyester fabrics. The test results are shown in Table 11 and Table 12. The test method was the same as described in Example 5.
TABLE 11__________________________________________________________________________E. P. C. after Printingconjugate polyester conjugate polyester conjugate polyestermonofilament monofilament monofilament monofilament monofilament monofilamentmesh fabric (A2) fabric (B2) mesh fabric (A3) fabric (B3) mesh fabric (A4) fabric (B4)load 0 3,000 0 3,000 0 3,000 0 3,000 0 3,000 0 3,000(kgf) time times time times time times time times time times time times__________________________________________________________________________ 5 1.00 1.00 1.00 0.74 1.00 1.00 1.00 0.77 1.00 1.00 1.00 0.7010 1.00 0.94 0.90 0.66 1.00 0.93 0.93 0.68 1.00 0.94 0.81 0.6215 0.92 0.90 0.79 0.52 0.94 0.86 0.80 0.55 0.96 0.90 0.69 0.5120 0.85 0.81 0.61 0.40 0.88 0.80 0.70 0.42 0.90 0.83 0.56 0.3925 0.81 0.76 0.54 0.31 0.81 0.74 0.66 0.36 0.83 0.77 0.48 0.2730 0.74 0.69 0.45 0.24 0.75 0.66 0.44 0.27 0.77 0.7135 0.66 0.60 0.40 0.19 0.70 0.60 0.70 0.6640 0.59 0.54 0.65 0.56 0.64 0.56__________________________________________________________________________
TABLE 12__________________________________________________________________________Tensile Modulus of Elasticity (%)conjugate polyester conjugate polyester conjugate polyestermonofilament monofilament monofilament monofilament monofilament monofilamentmesh fabric (A2) fabric (B2) mesh fabric (A3 fabric (B3) mesh fabric (A4) fabric (B4)load 0 3,000 0 3,000 0 3,000 0 3,000 0 3,000 0 3,000(kgf) time times time times time times time times time times time times__________________________________________________________________________ 5 100.0 100.0 100.0 80.5 100.0 100.0 100.0 81.1 100.0 100.0 100.0 78.410 100.0 98.3 93.3 72.9 100.0 97.8 95.0 72.8 100.0 98.5 94.1 69.715 97.7 95.5 86.9 65.5 98.6 94.8 87.3 66.7 97.9 93.7 88.0 60.020 93.2 89.9 79.4 57.0 92.5 88.1 74.5 59.3 93.5 89.3 76.0 55.125 88.8 84.0 68.2 46.1 89.2 85.6 68.5 47.2 88.0 84.6 64.0 44.230 82.2 79.1 60.1 39.8 82.6 78.9 60.2 38.6 83.2 78.835 74.6 72.6 51.8 29.7 75.5 74.0 76.1 72.440 69.9 65.5 70.3 65.4 70.4 65.0__________________________________________________________________________
The test results in Table 11 and Table 12 indicate that the present mesh fabrics A2, A3 and A5 have high after-printing E.P.C. and tensile modulus of elasticity which enhance the printing precision and printing durability of the fabrics. Accordingly, the present mesh fabrics are advantageously applicable for high-density, high precision screen printing.
On the contrary, in the case of the conventional polyester monofilament fabrics B2, B3 and B5, as the number of the printing times was increased, the printing durability of the fabrics was reduced. Conventional nylon monofilament fabrics, of which the test results are not presented herein, are inferior to the polyester monofilament mesh fabrics in the tensile modulus of elasticity. Accordingly, the conventional nylon monofilament mesh fabrics are unsuitable for application to high-density, high-precision screen printing.
Example 8
By following substantially the procedure described in Example 1 with respect to the mesh fabrics A1 to A5 and by adding yellow pigment (PID yellow No. 83, made by Repino Colour Kogyo Co., Ltd.) to the material of the sheath of the conjugate filaments, mesh fabrics X1 to X5 were obtained from the conjugate filaments each comprising the dope yellow-coloured sheath.
On the other hand, the mesh fabrics A1 to A5 as described in Example 1 were dyed in yellow colour, so that the mesh fabrics Y1 to Y5 made of the conjugate filaments each comprising the dyed sheath were obtained. Further, for comparison, the mesh fabrics B1 to B5 as described in Example 1 were dyed in yellow colour in the conditions as described in Table 13, so that the yellow-coloured polyester mesh fabrics Z1 to Z5 were obtained.
All the mesh fabrics exhibited a halation resisting property when exposed to light for the photomechanical process.
As understood from Table 13, the mesh fabrics X1 to X5 made of the conjugate filaments each comprising the dope-coloured sheath had no heat shrinking, and could be processed for forming a screen stencil with keeping the high qualities of the fabrics, whatever pattern may be formed on the screen. This is attributed to the unnecessity of the mesh fabrics X1 to X5 to be subjected to a dyeing process with low workability.
The present mesh fabrics Y1 to Y5 could be rendered halation preventive relatively easily. As the mesh fabrics Y1 to Y5 are unnecessary to be subjected to severe conditions for the dyeing, the deformation of the fabrics are relatively small. The mesh fabrics Y1 to Y5 are advantageously applicable for the process of a screen stencil having a finer pattern with high process stability.
On the contrary, the conventional polyester mesh fabrics Z1 to Z5 require severe conditions for the dyeing, and are heat shrinked to large extent. Accordingly, the mesh fabrics Z1 to Z5 are unsuitable for the process of a screen stencil having a fine pattern.
TABLE 13__________________________________________________________________________ dyeing conditions prepara-type of fabrics tion dyeing heat shrinkage(%)No meshmaterials pressure time time warp weft average__________________________________________________________________________X1 150dope-coloured conjugate 48 μm 0 0 0 0 0 0monofilamentsX2 200dope-coloured conjugate 48 μm " 0 0 0 0 0monofilamentsX3 250dope-coloured conjugate 40 μm " 0 0 0 0 0monofilamentsX4 270dope-coloured conjugate 34 μm " 0 0 0 0 0monofilamentsX5 300dope-coloured conjugate 34 μm " 0 0 0 0 0monofilamentsY1 150dyed conjugate monofilaments 48 μm atomos- 1.0 0.5 4.8 4.0 4.4 pheric pressureY2 200" 48 μm atomos- " " 4.7 4.5 4.6 pheric pressureY3 250" 40 μm atomos- " " 4.6 4.4 4.5 pheric pressureY4 270" 34 μm atomos- " " 5.2 4.5 4.4 pheric pressureY5 300" 34 μm atomos- " " 5.3 4.6 4.5 pheric pressureZ1 150dyed polyester monofilaments 48 μm high 4.0 2.0 13.8 13.5 13.7 pressureZ2 200" 48 μm high " " 13.7 13.4 13.6 pressureZ3 250" 40 μm high " " 13.8 13.6 13.7 pressureZ4 270" 34 μm high " " 14.1 13.6 13.9 pressureZ5 300" 34 μm high " " 14.0 13.8 13.9 pressure__________________________________________________________________________
Example 9
Electron micrographs of the mesh fabrics X1 to X5, Y1 to Y5 and Z1 to Z5 were taken to examine the surface state, and compared with each other. Table 14 shows the test results.
TABLE 14______________________________________type of fabrics surface stateNo. mesh materials of fabric______________________________________X1 150 dope-coloured conjugate 48 μm no foreign monofilaments matters, cleanX2 200 dope-coloured conjugate 48 μm no foreign monofilaments matters, cleanX3 250 dope-coloured conjugate 40 μm no foreign monofilaments matters, cleanX4 270 dope-coloured conjugate 34 μm no foreign monofilaments matters, cleanX5 300 dope-coloured conjugate 34 μm no foreign monofilaments matters, cleanY1 150 dyed conjugate 48 μm less foreign monofilaments mattersY2 200 dyed conjugate 48 μm less foreign monofilaments matersY3 250 dyed conjugate 40 μm less foreign monofilaments mattersY4 270 dyed conjugate 34 μm less foreign monofilaments mattersY5 300 dyed conjugate 34 μm less foreign monofilaments mattersZ1 150 dyed polyester 48 μm a lot of monofilaments foreign mattersZ2 200 dyed polyester 48 μm a lot of monofilaments foreign mattersZ3 250 dyed polyester 40 μm a lot of monofilaments foreign mattersZ4 270 dyed polyester 34 μm a lot of monofilaments foreign mattersZ5 300 dyed polyester 34 μm a lot of monofilaments foreign matters______________________________________
FIGS. 7 to 9 represent the microphotographs (magnification: of the mesh fabrics X3, Y3 and Z3, respectively. As understood from Table 14 and FIGS. 7 to 9, the present mesh fabrics X1 to X5 made from the dope-coloured conjugate monofilaments had a very clean surface. The present mesh fabrics Y1 to Y5 made of the dyed conjugate monofilaments were high-quality products which had less foreign matters adhered thereto, as compared with the conventional mesh fabrics Z1 to Z5 made from the polyester monofilaments.
Example 10
The mesh fabrics X1 to X5, Y1 to Y5, and Z1 to Z5 as described in Example 8, and the undyed mesh fabrics A1 to A5 and B1 to B5 as described in Example 1 were washed with a 0.2% neutral detergent aqueous solution, and dried. To each of the mesh fabrics, a PVA-vinylacetate type photosensitive resin emulsion NK-14 (made by Hoechst Co., Ltd.) were applied by lap-coating, and dried. The thickness of. the coating films formed on the mesh fabrics was in the range of 10 μm to 12 μm. Each mesh fabric having the photosensitive coating film was cured by exposure to light so as to have a fine pattern thereon.
The mesh fabrics each having the fine pattern were observed by use of an electron microscope. Table 15 shows the observation results.
TABLE 15______________________________________ halation state totaltype of fabrics prevention of evalua-No. materials effect pattern tion______________________________________X1˜X5 dope-coloured conjugate ⊚ ⊚ A monofilamentsY1˜Y5 dyed conjugate ○ ⊚ B monofilamentsZ1˜Z5 dyed polyester ○ X D monofilamentsA1˜A5 undyed conjugate Δ ○ C monofilamentsB1˜B5 undyed polyster X Δ D monofilamentsThe marks indicate the following, respectively:(the halation prevention effect)⊚superior in halation prevention effect○good in prevention effectΔprior in halation prevention effectX producing a halation(state of pattern)⊚high bonding strength, very clear in the whole pattern○high bonding strength, clear in the pattern edgesΔlow bonding strength, poor in the pattern edgesX substantially no bonding strength, incapable offorming a pattern(total evaluation)A superior in both of halation prevention effect andbonding strengthB good in both of halation prevention effect andbonding strengthC poor in either one of halation prevention effector bonding strengthD poor in both of halation prevention effect andbonding strength______________________________________
FIGS. 10 to 14 show the microphotographs (magnification: 500) of the mesh fabrics X5, Y5, Z5 and A5, and B5 each having the fine pattern formed thereon as described above. As these results and Table 14 indicate clearly, the present mesh fabrics, whether they are dyed or dope-coloured, had high halation prevention effect, and could be precisely provided with a pattern thereon as a screen stencil (see FIGS. 10 and 11, and the columns of X1 to X5 and Y1 to Y5 in Table 14). On the contrary, the conventional polyester monofilament mesh fabrics, though they could be rendered halation resistant by the dyeing, the fibrous surfaces of the conventional mesh fabrics became irregular, as shown in FIGS. 9 and 12, and the bonding strength was reduced by the dyeing. Accordingly, the conventional polyester monofilament fabrics could not be provided with a definite pattern thereon (see the columns of Z1 to Z5 in Table 14).
The mesh fabrics of the invention, which are not dyed, can be provided with a pattern thereon (see FIG. 13 and the columns of A1 to A5 in Table 14). In the case of the conventional polyester filament mesh fabrics, a definite pattern cannot be formed thereon, because of occurring of blurs and fogs on the pattern (see the columns of B1 to B5 in Table 14).
Industrial Applicability of the Invention
A mesh fabric of the invention has high dimensional stability, mechanical strength and bonding strength to a resin, which enables a precision printing screen to be processed with high production efficiency. Further, the present mesh fabric has high anti-static property, and provides a high workability during the use as a printing screen.
The present mesh fabric makes it possible to process a screen which has high ink squeezing properties and undergoes extremely less changes in the quality with the lapse of time and substantially no-discrepancy in the printings.
Accordingly, the mesh fabric of the invention is suitable for mass-production of screens to be applied to precision printing of electronic parts such as printed circuits, multiply boards, IC circuits, and so forth, with inexpensiveness and high production efficiency.
|
The mesh fabric is advantageously applicable for producing a printing screen. The mesh fabric consists essentially of conjugate monofilaments each having a core and a sheath. The sheath is formed of a material having high adhesive property to an emulsion and a resin used for making the screen. The core is formed of a material having high dimensional stability and elastic recovery property. The mesh fabric has a breaking elongation of from 15 to 40% and a breaking strength of not less than 25 kgf, and a correlation between the strength (kgf) and the elongation (%) in the elongation range of not less than 5%, in the stress-strain curve of the mesh fabric by the labelled strip method at the specimen width of 5 cm and the grip interval of 20 cm satisfying the following formula:
Y≧(X+1)×5/3.
The mesh fabric, which comprises such special sheath and core type conjugate filaments, is significantly improved in the dimensional stability and the adhesive property to resins. Production of a printing screen with high precision and workability is enabled. The mesh fabric, which has a relatively high strength and a corelation between the strength and the elongation in the special range as mentioned above, affords to produce a screen having small elongation at high tension and high printing stability.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application Ser. No. 62/165,474, filed May 22, 2015, which is incorporated by reference herein in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC OR AS A TEXT FILE VIA THE OFFICE ELECTRONIC FILING SYSTEM
[0004] Not applicable.
STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR JOINT INVENTOR
[0005] The inventors did not disclosed the invention herein prior to the 12 month period preceding the filing of this nonprovisional application.
BACKGROUND OF THE INVENTION
[0006] (1) Field of the Invention
[0007] The present invention, the Flow Shield generally relates to an apparatus and method that reduces the amount of silt, sediment, and debris entering a storm sewer during water runoff from a construction site. The apparatus is a rigid structure covered with an exterior filter that fits over the opening of a standard combination curb and gutter system. The device is placed over the standard combination curb and gutter system during site construction to remove silt and sedimentation from water entering the sewer system. The Flow Shield can be quickly installed over a any standard curb or gutter inlet system. Removal of the Flow Shield can be performed quickly and easily upon the complete of construction site activities. The Flow Shield is stackable, allowing a number of devices to be stacked together to facilitate transport of the devices from job site to job site. Stackability also reduces the space required for storage of the Flow Shield. The Flow Shield does not retain moisture allowing it to be stored immediately after use. The filter attachment and design facilitates efficient silt and sedimentation filtering and removal of debris.
[0008] (2) Description of Related Art
[0009] Storm water runoff is produced when precipitation from rain and snow melt flows over land and impervious surfaces and does not percolate into the land. As the storm water runoff flows over land and impervious surfaces it accumulates silt, sediment, pollutants and other debris. The silt, sediment, pollutants and other debris can contaminate the water if the water is left untreated. Once the storm water runoff enters a storm sewer system, the silt, sedimentation, and debris can accumulate within the system obstructing the flow of runoff. Federal, state, and local authorities regulate runoff pollution and limit the amount of silt, sedimentation, and debris within storm water runoff. These regulations require commercial and residential construction to minimize particulate in runoff and to prevent the flow of particulate matter into a sewer system.
[0010] The types of storm sewer drain inlets in common use include curb inlets, gutter inlets, and combination curb and gutter inlets. A curb inlet is just a vertical opening in the curb. A gutter inlet includes an opening in a horizontal section of the road. Gutter inlets may also include a vertical section of drain stemming from the horizontal opening. Gutter inlets typically have a grate covering the opening, while curb inlets are typically open without a grate. Combination curb and gutter systems have a vertical curb opening and a horizontal grated opening in the bottom of the gutter.
[0011] During construction of both residential and commercial buildings, grading and land excavation are typically ongoing throughout the duration of construction activities. Construction equipment such as bull dozers, back hoes, and excavators are constantly tracking mud and debris onto newly built roads and existing streets. Rainfall can wash the mud and debris into nearby storm sewers that are designed to carry the water to nearby tributaries and to water treatment facilities. Although seeding and mulching is common practice during construction, erosion of exposed earth especially during heavy storms can be substantial. Heavy rainfall can strip a construction site of loose silt and sediment. The silt and sediment may drain into a nearby storm sewer system. And, over time, the silt and sediment can accumulate within the sewer system.
[0012] Environment regulations prevent the accumulation of silt and sediment in a sewer system. A builder found to be in violation of storm water runoff regulations can be sanctioned by federal, state, and local officials. If silt and sediment do accumulate in a sewer system, the process of removing the particulate can be time consuming and costly to the builder or developer. Often it is necessary to rent expensive equipment and to hire specialized personnel to physically enter the structure or pipe and remove the sedimentation. This can add cost to the construction project and be dangerous to the personnel removing the silt and sediment. Additionally, OSHA mandates relating to subjecting a worker to a confined work space may be violated subjecting the builder to additional sanctions.
[0013] A number of devices have been disclosed and implemented to reduce silt and sediment discharge into a storm sewer system. The simplest storm water filtration device is created by placing one or more bales of straw in front of or on top of a storm drain. “Wattles” are another simple device commonly seen on active construction sites to filter debris out of runoff before it enters a storm drain. A “wattle” is a tubular mesh bag made of jute, hemp, or another woven material that is typically filled with wood chips such as hog fuel, or with some other absorbent material such as straw. Wattles are also placed on top of or in front of a sewer grate. Bussey, Jr. et al (U.S. Pat. No. 7,744,308 B2) discloses a oval-shaped tubular mesh bag containing filter material that is placed in front of a drainage element to filter debris from the runoff. Each of these three devices is difficult or impossible to stake down and all of them are subject to floating away during a heavy downpour. These devices usually do a poor job of trapping silt and sediment.
[0014] McGinn (U.S. Pat. No. 7,131,787 B2) discloses a drain inlet cover to filter runoff entering a gutter inlet. The device includes a horizontal section lying on the road and a vertical section covering the opening in the curb. Each section includes a filter member lying between two apertured polymeric members. This device requires that a berm be placed around the horizontal section of the device so that some sediment can settle out of the sediment-bearing liquid before it reaches the device. The requirement that a berm be fashioned to remove sediment from storm water severely limits the utility of the device. Additionally, this device limits the size of the vertical filter member which permits the free flow of runoff into the space above the filter member and below the curb. This allows runoff to flow without any silt, sediment or debris removal, which may violate environmental laws and regulations subjecting the builder to penalty.
[0015] Moody (U.S. Pat. No. 8,051,568 B2) discloses a temporary grate cover installed during construction activities. The device is composed of an expanded metal such as stainless steel with an attached geotextile fabric. The fabric is a filter weave high flow monofilament fabric, such as a woven polyethylene fabric. The device is attached to the grate with toggle bolts. This grate cover includes a flattened expanded metal with diamond shaped openings, which may be sized at about ¾×1¾″. Because curb inlets lack a grate in which to attach this device, this device can only be used on gutter inlet systems. The Moody device includes an embodiment for use with systems including a curb opening. This embodiment has one side turned up to form a vertical filter portion. But this embodiment offers no mechanism to attach the turned up portion of the device to the curb inlet, which weakens the device making less effective in heavy downpours or when heavy or a large quantity of debris is present in the runoff.
[0016] D'Andreta et al. (U.S. Pat. No. 7,901,160 B2) discloses a gutter grate cover molded onto a storm drain by driving over it or otherwise deflecting it from a generally upright orientation. The device is self-supporting and includes two substantially solid sheet portions containing apertures. A filter is positioned so that it filters runoff entering through the apertures. This device is molded to the curb by driving a bobcat or other wheeled vehicle over the device. But, concrete curbs are easily damaged by contact with construction equipment. The use of this device at a construction site may necessitate the use of remedial measures to remove and replace damaged curbs.
BRIEF SUMMARY OF THE INVENTION
[0017] The Flow Shield generally comprises a curb, grate, and combination curb and grate inlet temporary filtering system to filter silt, sedimentation and debris from runoff entering a storm water drainage system. The Flow Shield enables water to pass therethrough the storm sewer inlet, wile preventing a substantial portion of silt and debris flowing with the water from passing into the inlet. The Flow Shield generally includes a body that supports a filter medium. The body is sized to fit over the inlet and is sized for curb inlets, gutter inlets, and combination curb and gutter inlets. The body includes one or more support members encapsulated with a filter material that assists in the filtering of water entering the storm sewer inlet.
[0018] The body includes a grid or support structure formed from one or more supports. The grid provides points of attachment for the filter. The grid is rigid enough to withstand the force of the runoff while permitting the easy flow of said runoff. The filter includes geosynthetic materials, wire screens, mesh materials, and various synthetics, nylons and/or natural woven or knitted fibers and combinations thereof, or other appropriate filtration material.
[0019] Various aspects of the Flow Shield will become apparent to those skilled in the art upon reading the following detailed description, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of the Flow Shield covering a standard single wing curb inlet.
[0021] FIG. 2 is a perspective view of the Flow Shield covering a standard double wing curb inlet.
[0022] FIG. 3 is a perspective view of the Flow Shield covering a standard combination curb and gutter inlet.
[0023] FIG. 4 illustrates a side view of the Flow Shield.
[0024] FIG. 5 is a perspective view of the Flow Shield secured to a standard curb inlet with gravel bags.
[0025] FIG. 6 is a perspective view of the Flow Shield anchored to a typical combination curb and grate inlet with concrete tapping screws.
[0026] FIG. 7 is a perspective view of the Flow Shield with the filter shown above the cover.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The invention is described in detail in the following paragraphs with reference to the attached drawings. Throughout this detailed description of the invention, the disclosed embodiments and features are to be considered as examples, rather than being limitations to the invention. Modifications to particular examples within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to one of ordinary skill in the art. Further, reference to various embodiments of the disclosed invention does not mean that all claimed embodiments or methods must include every described feature. The various disclosed embodiments and features of the invention may be used separately or together, and in any combination. Terminology used herein is given its ordinary meaning consistent with the exemplary definitions set forth below.
[0028] The Flow Shield is a structure designed to be sit atop a storm sewer inlet. It fully covers the inlet and is anchored into the optimum position. The Flow Shield is composed of a rigid grid body covered with an attached filter. The body is composed of any material rigid enough to withstand the force of water runoff while permitting the easy flow of water through said body. The body may be composed of any high density material such as polyethylene, polyvinyl chloride, stainless steel, iron, or other suitable material. Each end of the Flow Shield follows the profile of a standard combination curb and gutter inlet which allows the ends of the Flow Shield to lay flush in the gutter or edge of the road. The Flow Shield encloses the entire curb or gutter grate inlet.
[0029] FIG. 1 illustrates a perspective view of the Flow Shield installed over a typical single wing curb inlet cover. The top 13 of the Flow Shield body lies flush with the top of the curb 2 . The bottom toe 5 of the Flow Shield grid lies flush along the edge of the gutter or road. The Flow Shield contains a number of ribs 11 that link the top 13 to the bottom toe 5 forming a grid. The ribs 11 allow water above the curb and at street level to enter the Flow Shield and to be filtered before entering the storm sewer system. The ribs 11 are flanked by a number of spaces 12 that are approximately 75 to 100 mm in width. Positioned at the outermost ends of the bottom toe 5 is a triangular space 10 . There are a total of two triangular spaces 10 per Flow Shield. Positioned at the outermost ends of the top 13 is an irregular space 14 . There are total of two irregular spaces 14 . Each irregular space 14 lies flush with the vertical sidewall of the curb 2 and flush with the top of the curb 2 . A transverse rib 4 separates each triangular space 10 from the irregular space 14 . The triangular spaces 10 in conjunction with the irregular spaces 14 form the sides 8 of the Flow Shield. The triangular spaces 10 and irregular spaces 14 allow water traveling along the curb to enter into the Flow Shield so that the water can be filtered as it enters the storm sewer system.
[0030] FIG. 2 depicts the Flow Shield covering a typical double wing curb inlet. The length of the Flow Shield is sufficient to cover the entire length of the double wing curb inlet. In one embodiment, the Flow Shield is approximately 4.42 m long. This length is sufficient to allow the Flow Shield to completely cover the entire inlet. FIG. 3 illustrates the Flow Shield covering a typical combination curb and gutter inlet. The Flow Shield is centered above the grate 20 of the inlet.
[0031] FIG. 4 illustrates a side view of the Flow Shield. The side 8 connects the top 13 to the bottom toe 5 . In one embodiment, the side 8 is approximately 0.68 meters long. The side 8 lies flush against the gutter or road at the point where the side 8 contacts the bottom toe 5 . Side 8 is of sufficient length to allow the Flow Shield to fully enclose a gutter grate 20 . Side 8 runs horizontally until it contacts the vertical edge of the curb 2 . When the side 8 meets the beginning of the vertical section of the curb 2 , side 8 curves and runs vertically 0.15 m the height of the curb 2 . Once the vertical portion of side 8 is the height of the curb 2 , the side 8 curves until the side 8 is horizontal and flush with the curb 2 . The top 13 is of sufficient width to allow gravel bags to be placed upon it to secure the Flow Shield over the sewer system inlet. The transverse rib 4 connects the side 8 to the top 13 of the Flow Shield forming the triangular space 10 and the irregular space 14 .
[0032] The Flow Shield must be secured in position to work properly. This can be performed by anchoring the device with gravel or with tapping screws. FIG. 5 illustrates the Flow Shield anchored to a curb inlet by gravel bags. Once the Flow Shield has been placed in the optimum location, bags of gravel 15 can be quickly positioned onto the top 13 of the Flow Shield. The placement of two or more bags of gravel will anchor the Flow Shield so that it is secured atop the curb inlet to filter runoff. Concrete tap screws may be used to secure the Flow Shield into position. FIG. 6 illustrates the Flow Shield secured onto a curb inlet via concrete tapping screws. The top 13 contains a plurality of circular openings or eyelets 40 running the length of the top 13 . Once the Flow Shield has been positioned atop the sewer system inlet, concrete tapping screws can be placed through eyelets 40 , which are located on the top 13 . Next, the concrete tapping screws can be tapped until they anchor the top 13 to the curb 2 . The bottom toe 5 has a plurality of circular openings or eyelets 42 running the length of the toe 5 . Concrete tapping screws can be tapped through the eyelets 42 and into the road to secure the Flow Shield.
[0033] FIG. 7 illustrates the filter of the Flow Shield. The filter utilizes a combination of non-woven filter fabric or similar high permeable mesh to create a two stage filtration system. The two-step filtration mechanism is achieved by combing a high filtration rate mesh 30 with a high flow rate mesh 32 . The high filtration mesh 30 runs the length of the bottom toe 5 and along the sides 8 of the Flow Shield. The high filtration mesh creates the vertical portion of the filtering system. The high flow rate mesh 32 runs the length of the top 13 of the device and creates the horizontal portion of the filtering system. The filter fabric fits over the grid completely covering it. The filter mesh overlaps the structure on all sides with an overlap of approximately 75 to 125 mm. The fabric mesh is secured with clips and/or adhesive along the edge of the grid. Tie wraps may also be utilized to secure the filter to the grid. The filter is removable and should be replaced as needed to properly filter runoff from the construction site. The filter may be constructed so that it can be washed with a water hose and soap. The curved shape of the grid provides the filter with a large surface area to maximize the filtration rate of the Flow Shield.
[0034] The first step in filtration removes silt and sedimentation as storm water passes through the high filter mesh 30 at a rate of approximately 6,170 liters per square meters. The first step utilizes filter media 30 with a high sedimentation and silt removal rate. This first step is the primary treatment for the storm water runoff. The second step is utilized in heavy rainfall events or similar events causing large quantities of water runoff. The filter media 32 utilized in the second stage has a high flow rate to remove large floating solids and debris.
|
The present invention relates to a curb, grate, and combination curb and grate inlet temporary filtering system to filter silt, sedimentation and debris from runoff entering a storm water drainage system. The invention comprises a body sized to fit over the inlet and includes one or more support members encapsulated with a filter material that assists in the filtering of water entering the storm sewer inlet.
| 4
|
This is a continuation-in-part application of U.S. Ser. No. 417,896 filed Apr. 6, 1995, now U.S. Pat. No. 5,498,451 which in turn is a continuation-in-part application of U.S. Ser. No. 07/964,051 filed Oct. 21, 1992 now U.S. Pat. No. 5,443,871.
FIELD OF THE INVENTION
The present invention relates to spacer elements for insulated glass assemblies having a single as well as a divided atmosphere therebetween.
BACKGROUND OF THE INVENTION
The prior art provides a complete plethora of insulated glass assemblies, sealant strips and spacer elements and improvements thereto used in insulated glass assemblies.
The modifications and improvements to the strips etc. have all had a common goal, namely, to improve the insulation capacity for such assemblies without sacrificing structural integrity or moisture degradation of the assembly.
Although the art is replete with such assemblies, it fails to provide an insulating sealant strip which provides:
i) warm edge technology;
ii) non-ultraviolet degradable material; or
iii) elastic deformation between the glass lites.
Typical of the art in the field of the present invention includes U.S. Pat. No. 4,576,841. This patent discloses the use of an aluminum foil into which is positioned desiccant material. Such an arrangement has two inherent limitations, namely:
i) aluminum is a thermal conductor which results in thermal transmission and thus obvious energy expenditures; and
ii) since the tube is solid, elastic recovery from the compression of glass lites engaged with the same is negligible.
Further, U.S. Pat. No. 4,113,905 discloses a composite foam spacer comprising an extruded tubular profile having an outer coating of foam material thereon. The spacer further includes projecting edges which project laterally relative to the longitudinal axis of the spacer. Although a useful arrangement, the spacer does not facilitate compression dampening and, if the spacer were compressed, this would result in unnatural force dispersion due to the projecting edges which may lead to breakage of the substrates. Further, if compressed, the spacer element may disrupt sealant material associated therewith thus leading to an ineffective seal.
Mucaria, in U.S. Pat. No. 4,368,226 provides a glass assembly in which there is included aluminum spacers. As such, the arrangement is limited similar to U.S. Pat. No. 4,576,841 as discussed herein previously.
Further prior art in the field of the present invention includes U.S. Pat. Nos. 4,536,424; 4,822,649; 4,952,430; 4,476,169; 4,500,572; and Canadian Patent Nos. 884,186; 861,839; and 1,008,307.
SUMMARY OF THE INVENTION
Thus, having regard to the prior art arrangements, there exists a need for a sealant strip which provides a partitioned atmosphere, high insulation value and hygroscopic capabilities without creating an unnecessarily complicated arrangement; the present invention fulfils this need.
According to one object of the present invention, there is provided an insulated glass spacer element comprising a pair of spaced apart substrate engaging members each having a top and bottom surface; a base extending between and connected to each bottom surface of each of the substrate engaging members, and a support member extending between the substrate engaging member and connected to the top surface of one of the substrate engaging members.
The spacer element is preferably a fabricated from a resiliently deformable material to allow flexure of the same.
In a preferred form, the support member extends diagonally between the substrate engaging surfaces to partition the area therebetween. Applicant has found that such an arrangement is well suited to dampening compression between substrates engaged therewith in an insulated glass assembly and accordingly, it is a further object of the present invention, to provide an insulated glass assembly comprising a pair of glass lites; an elastically deformable body having a first substrate engaging member associated therewith; a second substrate engaging member spaced from the first substrate engaging surface, the second substrate engaging surface being operatively associated with the body and extending therefrom, whereby when a glass lite is engaged with the first substrate engaging member and the second substrate engaging member, the second substrate engaging member facilitates limited resilient compression of the assembly.
The spacer element according to a further embodiment of the present invention may be used in combination with a similar spacer element to provide a multiple atmosphere insulated assembly. Such an arrangement is extremely useful for dual insulated window assemblies commonly used in highrises. Previously, aluminum extruded bodies not capable of providing warm edge technology had to be used for such an application. Thus, a further object of the present invention is to provide an insulated glass assembly having opposed substrates with an atmosphere therebetween and sheet material extending between the opposed substrates comprising a pair of glass lites; a sheet of flexible material, a pair of insulating spacer members, each of the spacer members having a sheet engaging member for engaging the sheet material, a substrate engaging member, each of the substrate engaging member and the sheet engaging member having an upper and lower edge, a base extending between and connected to each the upper edge of each the substrate engaging member and the sheet engaging member, a support member extending between the engaging surfaces and connected to the lower edge of the substrate engaging surface whereby when the substrates are engaged with the substrate engaging surfaces of each of the spacer members and the engaging surface of each of the spacer members is in facing relation, the sheet material extends within the atmosphere spaced from the opposed substrates, whereby when the substrates are engaged with the substrate engaging surfaces the sheet material extends within the atmosphere spaced from each of the substrates engaged with the insulating bodies.
In applications where compressive forces are not so extreme, a further embodiment of the present invention is provided which comprises a support member for supporting and spacing opposed substrates in a window construction comprising a self-supporting elastically deformable body having a pair of opposed and spaced apart arms each adapted to engage one of the substrates, the arms extending outwardly from the body at either end thereof, the body having a width sufficient to space the opposed substrates apart from one another, and desiccant receiving means associated with the main body and adapted to receive desiccant material therein.
In one variation of the present invention, the generally vertically oriented support member may function solely as a supporting member; alternately, this supporting element may be of a corrugated nature which functions to permit some flexing of the support member to relieve stress on double glass lites formed into an assembly where stress may be encountered due to wind or atmospheric conditions which will cause flexing of the glass panes or lites with consequent flexing of the spacer element or strip. In this way, where large surface areas of glass panes are used in conjunction with the spacer element, a degree of flexibility can be provided without disrupting the integrity of the spacer element.
In a still further embodiment, the vertically oriented as well as the angularly disposed supporting members of the spacer element may include additional reinforcing means such as by including an embossed structure thereon. Such an embossed structure could be in the form of a plurality of spaced apart ribs, etc.
A coating may be applied over the outer chamber or insulative body to protect the material therein, such a coating may be in the form of a silicon coating. Alternatively, a suitable end cap may be provided to protect the material within the outer chamber.
Preferably, the spacer strip of the present invention includes a integral polymeric support frame which includes a first generally horizontal arm, the angularly disposed support arm forming a second arm extending from one end of the first horizontal arm; a third generally horizontal arm extending from one end of the angularly disposed support arm; the vertically oriented support arm forming a fourth arm extending downwardly from the third horizontal arm. The first and third horizontal arms being generally parallel. In this arrangement, the first and third horizontal arms form the strip portions which engage the glass lites.
In a particularly preferred arrangement, the polymeric support frame is also provided with a fifth horizontal arm which extends from the fourth arm and is adjacent and parallel to the first horizontal arm. In this arrangement, the third horizontal arm and the fifth horizontal arm from the strip portions which engage the glass lites.
Having thus generally described the invention, reference will now be made to the accompanying drawings, illustrating preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a perspective view of one alternate embodiment of the spacer strip according to the present invention;
FIG. 2 is a perspective view of the strip as positioned between two substrates;
FIG. 3 is an end view of a further alternate embodiment of the spacer strip of the present invention;
FIGS. 4 through 7 are end views of the spacer strip according to further embodiments;
FIG. 8 is a perspective view of a part of an insulated window assembly utilizing one embodiment of the insulative spacer strip of the present invention;
FIG. 9 is an end view of the spacer strip illustrated in FIG. 8;
FIG. 10 is a laid-open view of the rigid polymeric support frame of the spacer strip illustrated in FIG. 9;
FIG. 11 is an end view of an alternate embodiment of the spacer strip of the present invention;
FIG. 12 is an end view of another alternate embodiment of the spacer strip of the present invention; and
FIG. 13 is an end view of a further alternate embodiment of the spacer strip of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, shown is a first embodiment of the present invention.
FIG. 1 illustrates a perspective view of a spacer member, generally indicated by numeral 40, comprising a body resiliently compressible material such as those discussed herein previously.
The spacer 40, as illustrated in FIG. 1, includes a base 42 extending between and connected to substrate engaging members 44 and 46. The members 44 and 46 project from the base 42. Extending diagonally between the members 44 and 46 is a support member which is flexibly connected at one end to one of the engaging members 44 and 46, shown in the illustrated example as member 48. The other end of the support member 48 is free.
The spacer 40, according to this embodiment, may be fixed between a pair of opposed substrates 14 and 16 as illustrated in FIG. 2, by providing a butyl material such as polyisobutylene between each substrate and a respective engaging member 44 or 46 or may be adhered thereto using other suitable materials or methods.
The structure of the spacer 40 of this embodiment is particularly efficient for compression damping to thus prevent seal disruption and/or substrate fracture. The support member 48, being diagonally disposed between the substrate engaging members 44 and 46, is useful for this purpose. Upon compression of the substrates 14 and 16, the engaging members 44 and 46 flex somewhat towards one another which, in turn, results in the support member absorbing at least some of the force.
The spacer 40 may be extruded in the form illustrated in the drawings, or may be formed from an elongated length or sheet. Applicant has found that the use of the polyethylene terephthalate class of polymers as well as the polyvinyl halide polymers provide these properties and are extremely useful for highly efficient insulated glass assemblies. These materials are generally elastically deformable and are capable of resilient compression, while additionally providing a warm edge unit.
Further, the support member 48, as disposed between the members 44 and 46 provides a longitudinal generally tubular opening into which may be charged desiccant, butyl material, silicone material and other such materials. Suitable desiccant material may be selected from, for example, zeolites, silica gel, calcium chloride, alumina etc. The material selected may be loose or dispersed in a permeable matrix of, for example, silicone. This material has been removed to more clearly illustrate the structure of spacer 40.
FIG. 3 illustrates yet a further embodiment of the invention in which the spacer 40 is in opposition with a similar spacer for a dual atmosphere assembly. In this arrangement, substrate engaging members 46 of each of the spacer 40 each function as sheet engaging menders for maintaining the sheet material 32 taut between the substrates 14 and 16.
The film divides the atmosphere between the substrates 14 and 16 into separate air spaces such as is known dual seal insulated glass units. The film may comprise any of the known materials employed by those skilled in the art e.g. vinylidene polymers, PVC, PET, etc. Where ultraviolet exposure is a concern, the sheet may comprise a suitable UV screening material, e.g. Tedlar™.
Suitable adhesives or butyl material may be positioned between the facing engaging members 46 for securing the same and sheet material together. Similar to the embodiment of FIG. 2, suitable adhesive materials will be provided for engaging menders 44 for sealing engagement with substrates 14 and 16.
A bead 50 of butyl material can be positioned adjacent the free end of the support member 48 of each spacer 40 to maintain the same and adjacent with the corner formed by the base 42 and substrate engaging member 44.
Due to the disposition of the support member 48 in the spacer 40, a tubular form 52 is created which may receive desiccant material therein.
In an alternate form, the base 42 may include desiccant receiving means such as pockets embossed in base 42 to receive desiccant material.
Further, although the embodiment illustrated in FIG. 3 comprises two separate spacers 40, it will be appreciated by those skilled in the art that the two may be coextruded as a single piece in which provision would be made to allow reception of the sheet material 32 therebetween.
FIGS. 4 through 7 illustrate further forms of the spacer in which similar elements from previous embodiments are denoted with similar numerals.
Referring to FIG. 4 in greater detail, a support member 60 extends between engaging members 44 and 46 to divide the same, similar to the support member 48 from previous embodiments. The primary differences in the structure of support member 60 reside in a transversely extending partitioning member 62 positioned adjacent base 42.
FIG. 5 shows a further embodiment in which the support member, represented by numeral 64 in this embodiment, includes two generally diagonal portions 66 and 68 joined by a transversely extending portion 70.
FIG. 6 represents a composite of the support members 60 and 64 of FIGS. 4 and 5, respectively. Support member 72 in this embodiment corresponds in structure to portion 66 illustrated in Figures and the lower portion of the support member illustrated in FIG. 4.
FIG. 7 illustrates yet another embodiment for the spacer in which the support member includes partitioning members 74 and 76. In this manner, the desiccated material area 78 is divided as is the hollow air containing area 80.
In the embodiments illustrated in FIGS. 4 through 7, as well as herein previously, each spacer 40 may include a cap 58 comprising a polysilicone and desiccant material therein. This material would, in use, be directed to the interior volume of the window assembly.
The use of the partitioned structure for the spacer improves the thermal performance of the spacer by breaking the conductivity path in the silicone and separating the air filled area into a plurality of areas.
Reference will be initially made to FIGS. 8 and 9, which illustrate yet another embodiment of the spacer of the present invention.
The spacer strip of this embodiment, generally designated by reference numeral 90, includes a first insulative body 92 and a second insulative body 94. The first insulative body 92 is a generally hollow body which includes air therein, air being known as a good insulative material. Alternatively, the first insulative body 92 may include any suitable insulative material therein (not shown). The second insulative body includes a desiccant material 96 therein which may be selected from those materials discussed herein previously.
The insulative bodies 92 and 94 are formed by a rigid polymeric support frame structure, generally designated by reference numeral 97.
The rigid polymeric support frame member 97 is preferably of a one-piece unitary construction, although other constructions may be utilized such as two or more different coextruded or laminated strips.
The rigid polymeric support frame 97, as best illustrated in FIG. 9, includes a first arm 98 which is generally horizontally oriented, a second arm 100 which is generally angularly oriented, a third arm 102 which is generally horizontally oriented and is generally parallel to the first arm 98, a fourth arm 104 which is generally vertically oriented and a fifth arm 106 which is generally horizontally oriented.
The support frame 97 preferably has a thickness of approximately 0.005" to 0.030 inch and is of any suitable material which is self-supporting and suitably rigid such as polyolefins, polyesters, silicones and polyamides; polyesters being particularly preferred. If desired, the support frame 97 may also have a metallized surface or surfaces.
As best seen from FIG. 9, the fifth arm 106 is preferably parallel, adjacent and coextensive with the first arm 98; although the first arm 98 may be shorter or larger than the fifth arm 106. In a particularly preferred form, the fifth arm 106 and the first arm 98 are fixedly secured together by way of any suitable adhesive means (not shown) and the first arm 98, the second arm 100 and the third arm 102 form a generally "Z" shaped configuration.
Both the second arm 100 and the fourth arm 104 preferably have embossments 108 thereon. Such embossments 108, which may be in the form of spaced apart ribs, add strength to the support frame structure 97. It is contemplated that the embossed structures 108 may also include a desiccant material therein as previously discussed for earlier embodiments.
As will be noted, from FIG. 9 in particular, the second arm 100 forms a common border for each of the insulative bodies 92 and 94.
An end member 110 may be provided which covers and protects the desiccant material 96 in the second insulative body 94 and extends from the fifth arm 106 to the third arm 102. Such an end member may be in the form of any suitable polymeric coating or may be in the form of an end cap of any suitable material. Preferably, such an end member is in the form of a silicone coating having a UV resistant additive and further having the property of preventing rapid moisture absorption and saturation of the desiccant material 96 when exposed to atmospheric conditions, and providing sufficient necessary moisture absorption when between two panes of glass.
As best illustrated in FIG. 8, when the spacer strip 90 of the present invention is assembled between two panes of glass 116, the third arm 102 and the fifth arm 106 are fixedly secured to the panes of glass 116 by way of any suitable adhesive.
FIG. 10 illustrates the rigid polymeric support frame 97, as described above with reference to FIGS. 8 and 9, in a laid out condition. The embossments 108 on the second arm 100 and the fourth arm 104 are readily apparent from this Figure. Although in FIG. 10, the embossments 108 on the second arm 100 are shown on the top surface, and the embossments 108 on the fourth arm 104 are shown on the bottom surface, it will be understood that the embossments 108 could be on either or both of the surfaces of arms 100 and 104.
To form the spacer strip, the rigid polymeric support frame 97 is bent along the margins 109 to form the first horizontal arm 98, the second angularly disposed arm 100, the third horizontal arm 102, the fourth generally vertical arm 104 and the fifth horizontal arm 106 (see polymeric support frame 97 in the spacer strip illustrated in FIGS. 8 and 9).
FIG. 11 illustrates an alternative embodiment of the present invention. The embodiment of FIG. 11 is very similar to the embodiment illustrated in FIG. 9, with like reference numerals designating like parts.
In the embodiment of FIG. 11, however, the fourth arm 104 is of a corrugated construction, which permits some flexing of this support member to release stresses. All other elements of this embodiment are as shown and described with reference to FIGS. 8 to 10.
FIG. 12 illustrates another embodiment of the spacer strip 90 of the present invention, which again is very similar to the embodiment of FIG. 2, with like reference numerals designating like parts. In the FIG. 12 embodiment, the support frame 97 does not include a fifth arm. The end cap 110 covering the desiccant material 96 extends from the first arm 98 to the third arm 102. In this embodiment, the first arm 98 and the third arm 102 form the strips which engage the glass panels, and are affixed thereto by any suitable adhesive.
A further embodiment of the present invention is illustrated in FIG. 13. In this embodiment, a first arm 120 is provided which is generally horizontal. A second arm 122, which is generally vertical, extends upwardly from one end of the first arm 120. A third arm 124 which is parallel to the first arm 120 extends from the second arm 122 and a fourth arm 126 is angularly disposed and extends downwardly from the third arm 124, the fourth arm 126 has a free end which is adjacent the point where the first arm 120 and the second arm 122 are joined. The fourth arm 126 forming a common border between the first and second insulative bodies 92 and 94. In this arrangement, the first arm 120 and the third arm 124 form the glass lite engaging strips and the end cap 110 covering the desiccant material 96 extends from the first arm 120 and the third arm 124.
As those skilled in the art will realize, these preferred illustrated details can be subjected to substantial variation, without affecting the function of the illustrated embodiments. Although embodiments of the invention have been described above, it is not limited thereto and it will be apparent to those skilled in the art that numerous modifications form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.
|
There are disclosed spacer elements for use in insulated glass assemblies of the single and multiple atmosphere type which incorporate non-thermally conductive materials as the main structural support member in the assembly. The result is a lightweight, warm edge assembly.
| 4
|
PRIOR APPLICATION
[0001] This application is a U.S. national phase application claiming priority from Swedish Patent Application No. 0502042-5, filed 15 Sep. 2005.
[0002] 1. Technical Area
[0003] The present invention concerns an improvement of the cooling, washing, and exchange of fluid in a continuous digester for the production of cellulose pulp.
[0004] 2. The Prior Art
[0005] FIG. 1 shows a typical design of the lower part of a continuous digester. A lower strainer section 2 is present in this digester from which consumed cooking fluid is withdrawn from the column of pulp in the digester. Dilution fluid or washing fluid WL is introduced into the bottom of the digester through vertical 4 V or horizontal 4 H dilution fluid nozzles or washing fluid nozzles. A certain amount of dilution fluid or washing fluid may also be added through nozzles 4 Sc in arms of the rotating bottom scraper and through a conventionally central pipe 4 C that opens out in the centre of the column of pulp in the digester.
[0006] In the prior art design shown in FIG. 1 , one or more rows of strainers 3 a / 3 b may form the actual strainer section, where each row of strainers comprises strainer surfaces 22 a / 22 b together with a withdrawal volume 20 arranged at each strainer surface, and a collection chamber 21 under the withdrawal volume from which consumed cooking fluid is led away to a recovery system, the flow labelled REC. The collection chamber 21 may be located also outside of the digester shell in what is known as an “external header”. When it is desired to increase the production capacity of the digester, i.e. to increase the number of tonnes of digested pulp per day, the speed of the chips and the column of pulp down through the digester increases, while it is necessary at the same time to withdraw a greater amount of consumed cooking fluid and a greater volume of added dilution fluid or washing fluid from the strainer section.
[0007] This results in the lifting force from the upwards flow of fluid established at the bottom counteracting the tendency of the chips and column of pulp to sink, and this leads to the column of pulp easily becoming stuck such that output from the bottom of the digester is made more difficult, and sometimes even ceases completely.
[0008] Increasing the amount of dilution fluid or washing fluid added per unit of time at the nozzles 4 V/ 4 H/ 4 Sc/ 4 C arranged at the bottom proportionally to the increase of production, with the aim of maintaining a constant degree of dilution and washing per tonne of digested pulp, ensures that the upward lifting force on the chips and column of pulp increases proportionally with the increase in production. There is thus an upper limit to the production capacity for each digester with a bottom of conventional design with a withdrawal section 2 and with the addition of dilution fluid or washing fluid.
[0009] Other types of strainer design for continuous digesters are known, but these have been implemented for particular reasons and they solve totally different problems.
[0010] U.S. Pat. No. 5,236,554 reveals a strainer design with which it is desired alternately to add new cooking fluid enriched with chemicals in one of four sections arranged at the periphery of the digester wall around the column of chips, and to withdraw cooking fluid from an opposite sector. The particular addition sector and the particular withdrawal sector of these four sectors are varied over time, such that it possible to reduce radial temperature gradients and obtain an even digestion of the chips over the complete cross-section of the column of chips. The addition sectors can be designed as wall sections lying next to strainer surfaces, with nozzles arranged in these wall sections. The technology is most suitable at high locations in the digester where it is desired to have internal circulation and adjustment of the alkali profile, and it suffers from the disadvantage that only 25% of the strainer surface seen in the direction of the circumference of the digester is actively used as withdrawal strainer at any moment in time. The technology is not suitable for withdrawal sections in which there is instead a very high demand placed on the strainers (i.e. a large volume of withdrawn cooking fluid per unit of strainer area) around the complete digester, as is the case for the bottom strainer sections in, principally, overloaded digesters.
[0011] Thus U.S. Pat. No. 5,236,554 reveals something completely different than adding new cooking fluid enriched with chemicals through central pipes and only withdrawing consumed cooking fluid from the strainers in the wall of the digester, which technology ensures that only chips in the centre of the column of pulp are exposed to fresh cooking fluid and the chips in the column of pulp along the walls of the digester are exposed only to exposed cooking fluid.
[0012] The technology with crossed or alternating addition and withdrawal around the wall of the digester is a technology that is revealed also in SE 145,257 (dated 1952).
[0013] U.S. Pat. No. 6,123,808 describes another variant of the addition of dilution fluid or washing fluid at the bottom of the digester. A dispersion and strainer area that runs around the circumference is used in this case as a distributor of the added dilution fluid or washing fluid, which dispersion and strainer area is arranged directly under the lowermost withdrawal strainer. The aim here is to obtain a more even distribution of dilution fluid or washing fluid around the complete circumference of the digester, in a manner that differs totally from the distribution that can be achieved with local dilution fluid or washing fluid nozzles. An important aspect of this solution is that the relevant dispersion and strainer area must cover a larger diameter than that of the strainer area of the withdrawal strainer positioned above it. The disadvantage of this design is that the injection pressure for fluid into the column of pulp from the dilution fluid or washing fluid that is added though the dispersion and strainer area will be very low. The added dilution fluid or washing fluid can risk also being drawn directly to the strainer that lies above the dispersion and strainer area without passing in practice through any significant volume of pulp or chips in the column of pulp.
THE AIM OF THE INVENTION
[0014] The primary aim of the invention is to improve the cooling, dilution and washing principally at the bottom of the digester in continuous digesters.
[0015] A second aim is that of being able to increase the production of existing digesters without experiencing problems with the flow of the column of chips in the digester when the volume of dilution fluid or washing fluid that is added at the bottom of the digester increases in proportion with the increase in production while essentially maintaining constant the dilution fluid or washing effect.
[0016] A further aim is to reduce the lifting force on the column of chips in the bottom wash, where the upwards flow from the fluid added at the bottom can be reduced by the establishment of several layers of upward flow on top of each other instead of these being formed at the same cross-section of the digester.
[0017] A further aim is to be able to establish a further washing zone at the lower part of the digester without needing to reconstruct the central pipe of the digester, which central pipe is always otherwise used in a conventional manner for the addition of digester circulations above the row of strainers located lowermost in the digester.
SUMMARY OF THE INVENTION
[0018] The arrangement concerns an improved design for at least one of the cooling, dilution and washing at the bottom of a continuous digester for the production of cellulose pulp. By arranging at least one extra strainer section above the lowermost strainer section, with the addition of washing fluid or dilution fluid between the extra strainer section and the lowermost strainer section, more washing fluid can be added at the bottom of the digester without counteracting the flow of the column of chips. This provides space for the increase of production, for improvement of the flow of the column of chips, or for combinations of these effects while retaining good cooling, washing and dilution at the bottom of the digester.
DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a conventional design of a bottom strainer with the addition of dilution fluid at the bottom of a continuous digester;
[0020] FIG. 2 shows a first embodiment of the invention where an extra row of strainers has been arranged directly above the existing bottom strainer;
[0021] FIG. 3 shows an enlarged view of the design according to FIG. 2 ;
[0022] FIG. 4 shows a view seen in the section IV-IV in FIG. 3 ;
[0023] FIG. 5 shows an alternative embodiment of the invention with two extra rows of strainers arranged directly above the existing bottom strainer, where these extra rows of strainers are constituted by round strainers of the type known as “manhole strainers”.
DETAILED DESCRIPTION OF THE INVENTION
[0024] FIG. 2 shows a first embodiment of the invention, where the bottom design comprises an arrangement for the addition and withdrawal of fluids to a digester that is used for the continuous cooking of cellulose pulp. Wood chips are continuously fed through an inlet at the top of the digester (not shown in the drawing) and cooked cellulose pulp is continuously output through an outlet 10 at the bottom of the digester. At least one strainer section 2 is arranged in the digester, in association with the bottom of the digester with strainer surfaces 22 c (or similarly 22 a , 22 b in FIG. 1 ) arranged in the strainer section arranged in the direction of the circumference of the wall of the digester for the withdrawal of consumed cooking fluid. Nozzles 4 V, 4 H, 4 Sc for the addition of dilution fluid or washing fluid are arranged under the lowermost strainer section 2 and between the lowermost strainer section 2 and the outlet 10 arranged in the bottom of the digester. A number of vertically directed nozzles 4 V are normally located in the curved bottom end wall of the digester evenly distributed around the circumference. These may typically constitute 10-30 nozzles, or more, in a digester with a diameter of 8 meters.
[0025] The vertical nozzles 4 V are supplemented with a number of dilution nozzles 4 H directed in a horizontal direction that open out into the wall of the digester just above the curved bottom wall but under the lowermost row of strainers. The number of these nozzles may constitute 10-30 in a digester with a diameter of 8 meters.
[0026] Addition of dilution fluid or washing fluid takes place in certain digesters also through the rotating bottom scraper through nozzles 4 Sc arranged in the bottom scraper. One outlet on each arm is shown in the drawing, but several of these outlets may be present across the arm of the bottom scraper, from the centre of the bottom scraper and out to the outer end of the arm of the bottom scraper.
[0027] In addition to these dilution nozzles in the bottom of the digester, there is also an outlet from a central pipe positioned at the level of the lowermost row of strainers 2 , often just above this row of strainers, but the flow from this central pipe contributes to the dilution or washing process at the bottom of the digester.
[0028] FIG. 2 shows that the strainer section is constituted by strainer surfaces 22 c that are located in the pattern of the squares of a chessboard, a pattern that is known as “staggered screens”, where these strainer surfaces in each row of strainers 3 a , 3 b has a blind plate 22 d between each strainer surface, which blind plate 22 d has a surface area that essentially corresponds to that of the surrounding strainer surfaces 2 c . These types of rows of strainer are normally located in strainer sections with several rows of strainers, in which rows of strainers that lie above or below a row of strainers have strainer surfaces that are displaced such that a chessboard pattern is formed. This design is often chosen if it is desired to keep the cost of the strainer section low, while at the same time having a high withdrawal capacity, since it is the case that each strainer surface 22 c has the capacity to drain the column of chips also in those parts that are located as neighbours to the blind plates, i.e. the strainer surfaces drain the column of chips in the direction of the circumference a good deal into half of the extent of the neighbouring blind plate in the direction of the circumference. The invention can, of course, be used also for strainer sections of the type that is shown in FIG. 1 , where each row of strainers is constituted by a continuous strainer surface that runs in the direction of the circumference. All strainer surfaces in this description may be constructed of what are known as “rod strainers” or they may be simpler plates with slits.
[0029] At least one extra strainer section 30 is arranged for the withdrawal of consumed cooking fluid according to the invention above the lowermost strainer section 2 at a distance between the uppermost part of the lowermost strainer section 2 and the lowermost part of the extra strainer section 30 . Furthermore, a number of extra nozzles 34 are arranged for the addition of dilution fluid or washing fluid distributed around the circumference of the digester between the uppermost part of the lowermost strainer section 2 and the lowermost part of the extra strainer section 30 , which extra nozzles are provided with fluid 33 with the aid of pumps, which fluid is continuously added into the column of pulp through the outlets of these nozzles 34 .
[0030] The distance between the uppermost part of the lowermost strainer section 2 and the lowermost part of the extra strainer section 30 is the distance 31 in FIG. 2 , which corresponds to a small section of blind plates where the extra nozzles 34 are arranged: this distance is less than the bottom diameter of the digester. This distance typically lies within the interval 0-8 metres. The variant in which this distance is zero means that the nozzles are located at the interface between the uppermost part of the lowermost strainer section 2 and the lowermost part of the extra strainer section 30 .
[0031] In one advantageous embodiment, the distance between the uppermost part of the lowermost strainer section 2 and the lowermost part of the extra strainer section 30 is considerably less than the height of the extra strainer section 30 , i.e. the distance is less than 2 meters, and preferably less than 1 meter. A normal row of strainers, which may establish the extra strainer section, conventionally has a height of between 1.5 and 2 meters in digesters with production capacities of 1,500-3,000 tonnes per day.
[0032] A compact reconstruction of the washing and dilution zone of the digester is obtained in this way that infringes to a minimal degree on the cooking zone that lies above it. The distance can, however, in certain cases be increased if changes to the cooking process are made at the same time, while even so retaining a sufficiently long cooking zone. This applies primarily to those digesters in which what is known as a long “Hi-heat” wash is used at the bottom of the digester, in which the process is changed such that parts of the original Hi-Heat zone are used as cooking zone. This zone may correspond to 30% or more of the total retention time of the chips in the digester, in older digesters with Hi-Heat wash.
[0033] FIG. 3 and FIG. 4 show in more detail the design with the extra nozzles 34 and the withdrawal volume 30 . The extra nozzles 34 are located arranged such that their openings have their outlet in the wall 40 of the digester between the uppermost part of the lowermost strainer section and the lowermost part of the extra strainer section. Each extra nozzle 34 is provided by the connecting pipes 37 with dilution fluid or washing fluid from a common distribution channel 38 that runs around the digester, and which is in its turn provided with dilution fluid or washing fluid by a pump shown schematically in FIG. 4 .
[0034] It is preferable that the strainer surface of the lowermost strainer section 2 , the strainer surface of the extra strainer section 30 and the openings of the extra nozzles 34 are all arranged at essentially the same diameter in the wall of the digester, something that is normally the case if manhole strainers are used that have been post-installed.
[0035] The extra strainers may otherwise be mounted in an inner digester wall that constitutes a wall section that is extended downwards from a superior strainer section, which means that the strainer surface of the lowermost strainer section 2 and the openings of the extra nozzles 34 are both arranged at essentially the same diameter in the wall of the digester, while the strainer surface of the extra strainer section 30 is located at a smaller diameter in this wall section that has been extended downwards.
[0036] The additional extra nozzles 34 are evenly distributed around the circumference of the digester and they are present in such a number that the distance around the circumference between neighbouring extra nozzles is less than 3 meters, preferably less than 2 meters.
[0037] It is appropriate that the nozzles have an opening that delivers a concentrated jet into the column of pulp, but they may have openings that are oval or slits in the direction around the circumference. Addition of fluid may, in one extreme variant in which it is desired to achieve greater volumes of added fluid between the extra strainer section and the lower strainer section, also take place through what is essentially one single continuous slit that runs around the circumference. It is advantageous for achieving the best penetration effect into the column of pulp that the slit of the openings of the nozzles are subject to a controlled drop in pressure for the establishment of a high injection velocity of fluid into the column of pulp.
[0038] The lower strainer section 2 is constituted by at least one row of strainers, preferably by at least two rows of strainers, as is shown in FIG. 2 , where each row of strainers 3 a , 3 b consists of strainer plates or rod strainers arranged in the direction of the circumference around the digester. A collecting channel 20 is arranged at each row of strainers 3 a , 3 b for the cooking fluid that has been withdrawn through the strainers in this row of strainers, where each collection channel has at least one emptying arrangement 21 for the removal of the withdrawn cooking fluid.
[0039] The extra strainer section 30 is constituted by at least one row of strainers 23 , where each row of strainers consists of strainer plates or rod strainers arranged in the direction of the circumference around the digester. A collecting channel 39 is arranged at each row of strainers for the cooking fluid that has been withdrawn through the strainers in this row of strainers, where each collection channel has at least one emptying arrangement 35 , 36 for the removal of the withdrawn cooking fluid.
[0040] Also the extra strainer section 23 may consist of at least one row of strainers with several strainer sections 23 b where the strainer sectors have wall sections between them in the form of blind plates 23 d that do not have strainer surfaces. A variant is shown in FIG. 5 in which the strainer sectors are round, of the type known as manhole strainers, and they are arranged in two rows 30 a , 30 b.
[0041] The extra strainer section 23 may also consist of square strainer sectors of the type shown in FIG. 2 for the rows of strainers 3 a , 3 b , and arranged in a pattern that forms a chessboard around the circumference of the digester (an arrangement known as staggered screens).
[0042] The invention can be modified in a number of ways within the framework of the claims. Several copies of the extra strainer section 30 and the nozzle section 31 may, for example, be located one above the other, such that several positions for the addition of dilution fluid are obtained at several heights in the bottom of the digester.
[0043] An extra nozzle section can also be located above the extra row of strainers 30 in the variant that is shown in FIG. 2 .
[0044] While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims.
|
The arrangement concerns an improved design for at least one of the cooling, dilution and washing at the bottom of a continuous digester for the production of cellulose pulp. By arranging at least one extra strainer section above the lowermost strainer section, with the addition of washing fluid or dilution fluid between the extra strainer section and the lowermost strainer section, more washing fluid can be added at the bottom of the digester without counteracting the flow of the column of chips. This provides space for the increase of production, for improvement of the flow of the column of chips, or for combinations of these effects while retaining good cooling, washing and dilution at the bottom of the digester.
| 3
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to building constructions in general and more particularly to a novel frame or casing construction for secure mounting in wall openings to support and cooperate with doors and windows occupying the openings.
2. Brief Description of the Prior Art
Heretofore, the information and construction of frames and casings for doors and windows has required the use of carpenters of the highest skill and rate of pay. Further, the construction of casings such as openings in walls did not always result in properly hung doors and windows regardless of the skill of the artisan.
With these considerations in mind, it is an object of the present invention to provide a pre-fabricated casing assembly for wall openings which is readily adapted to the wall opening and which does not require the use of skilled workmen to install.
Another object of the present invention is to provide a novel pre-fabricated casing assembly for wall openings which may be installed with the component members thereof disposed in true vertical or horizontal potitions regardless of the possible departure from plumb or level lines of the edge facings of the openings.
A further object of the present invention is to provide a novel pre-fabricated casing assembly for wall openings which is so constructed and arranged that installation is achieved by a positive clamping action against the wall faces at each side of the opening.
A further object of the present invention is to provide a novel door jamb which is of a two piece construction having an overlapping portion readily spring loaded so as to bias clamping portions into the door frame defining the opening.
In one form of the invention, the door jamb includes the two piece construction having overlapping portions which are secured together by a fastener means. Clamping portions are engageable with opposite sides of the door frame and are normally biased into secure engagement with the opposite sides of the door frame by means of the spring loading of the overlapped portions in cooperation with the fastening means.
Therefore, a long standing need is present to provide a door jamb which has a positive clamping action and a spring biasing means urging the clamp portions into engagement with the door jamb.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings in which:
FIG. 1 is a front elevational view of the novel door jamb installed in a typical door opening of a building;
FIG. 2 is an enlarged transverse sectional view of the novel door jamb taken in the direction of arrow 2--2 of FIG. 1;
FIG. 3 is a view similar to the view of FIG. 2 showing the installation of the door jamb including door hardware as shown in FIG. 1 as taken in the direction of arrows 3--3 thereof;
FIG. 4 is a cross-sectional view of the installed door jamb and door hardware as taken in the direction of arrows 4--4 of FIG. 1; and
FIG. 5 is a front perspective view of the novel door jamb preparatory to installation on a door frame.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a building is illustrated by numeral 10 which includes a door 11 occupying an opening defined by the opposing surfaces of a U shaped frame 12. The door 11 is mounted on a door jamb 13 by means of a conventional hinge 14. Preferably, the frame 12 is composed of wood and the door jamb 13 is composed of metal. The subject matter of the present invention is represented by the numeral 13 and is indicated in the general direction of arrow 13 in FIGS. 2 and 3.
Referring to FIG. 2, the door jamb 13 is composed of a two piece construction having numerals 15 and 16 respectively. Each of the pieces 15 and 16 includes a clamp portion 17 and 18 which represent inwardly disposed edge marginal regions which are intended to be pressed into the opposite sides of the wooden door frame 12. Preferably, the frame 12 is provided with grooves 20 and 21 for receiving the clamps 17 and 18 respectively.
The pieces 15 and 16 further include a pair of overlapping sections which are represented by numerals 22 and 23 which form a compression mechanism in cooperation with a fastening means such as screw 24. A cap 25 covers the mechanism when assembled. The overlapping portions or sections 22 and 23 are arranged so that section 22 includes a semicircular bead 26 which is adjacent the face of the frame 12 and this bead is overlapped by section 23 which includes a U shaped member having a pair of pressure points 27 and 28 engageable with the section 22. A hole 29 engages with the threads of the screw 24 as it passes through a registered hole 30 in the section 23 so that the section 23 is pulled towards the section 22 and the pressure points 27 and 28 resist this action. The action is further increased by means of the screw 24 engaging into the frame 12 as shown in FIG. 3.
Referring now in detail to FIG. 3, it can be seen that when the screw 24 has been fully turned so that its countersunk head rests in hole 30, a load is placed on the section 22 drawing it toward the section 23 in the direction of arrow 31. Also, it is to be understood that this compressive action draws the clamps 17 and 18 in the direction of arrows 32 and 33 so that the opposite sides of the frame 12 are suitably engaged and secured. The cap 25 is then placed over the section 23 to protect the screws or fastening means 24.
FIG. 3 further illustrates the mounting of the hinge 14 onto the door jamb by means of a screw such as screw 35 insertably disposed and threadably engaged into a mating receptacle 36. By these means, the door jamb 13 is secured to the frame 12 and the door 11 is suitably mounted onto the jamb by means of the hinge 14.
Referring now to FIG. 4, it can be seen that the jamb is suitably secured to the frame 12 by means of the compression mechanism comprising the overlapping sections 22 and 23 in cooperation with the mounting screws 24. The clamping portions 17 and 18 are readily engaged with the slots 20 and 21 and the jamb is fixedly secured to the frame. The door is mounted by the hinge 14 and no further installation or adjustment is necessary or required.
In FIG. 5, an exploded perspective view of the novel door jamb of the present invention is illustrated wherein it can be seen that the overlapped portions 22 and 23 form a holding mechanism when the screw 24 is inserted through the registered holes 29 and 30 respectively.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.
|
A door jamb is disclosed herein of two piece construction including overlapping portions secured together by a screw and clamp portions engageable with the opposite sides of a door frame. The overlapping portions operate as a movable assembly which is spring biased to forcibly urge the clamp portions into secure engagement with the frame.
| 4
|
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part application of an application entitled “Ocular Fundus Auto Imager”, filed Dec. 16, 2002, assigned Ser. No. 10/311,492, now U.S. Pat. Ser. No. 7,025,459 which is a national phase application based on a Patent Cooperation Treaty application entitled “Ocular Fundus Auto Imager”, filed Jul. 6, 2001, assigned Ser. No. PCT/US01/21410, which is a continuation of and claims priority to a United States application entitled “Ocular Fundus Auto Imager”, filed Aug. 25, 2000, assigned Ser. No. 09/649,462, now U.S. Pat. No. 6,296,358 and which application claims priority to the subject matter disclosed in a provisional application entitled “FUNDUS AUTO IMAGER”, filed Jul. 17, 2000 and assigned Ser. No. 60/218,757 all of which applications are directed to an invention made by the present inventors and assigned to the present assignee.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of ocular imaging, and, more particularly, to devices for imaging the ocular fundus.
2. Description of Related Art
The term ocular fundus refers to the inside back surface of the eye containing the retina, blood vessels, nerve fibers, and other structures. The appearance of the fundus is affected by a wide variety of pathologies, both ocular and systemic, such as glaucoma, macular degeneration, diabetes, and many others. For these reasons, most routine physical examinations and virtually all ophthalmic examinations include careful examination of the ocular fundus.
Routine examination of the ocular fundus (hereinafter referred to as fundus) is performed using an ophthalmoscope, which is a small, hand-held device that shines light through the patient's pupil to illuminate the fundus. The light reflected from the patient's fundus enters the examiner's eye, properly focused, so that the examiner can see the fundus structures.
If a hard copy of the fundus view is desired, a device called a fundus camera can be used. However, to use existing fundus cameras successfully is a very difficult undertaking. The operator must (1) position the fundus camera at the correct distance from the eye, (2) position it precisely in the vertical and horizontal directions in such a way that the light properly enters the pupil of the patient's eye, (3) refine the horizontal and vertical adjustments so that the light reflected from the front surface of the eye, the cornea, does not enter the camera, (4) position a visual target for the patient to look at so that the desired region of the fundus will be imaged, and (5) focus the fundus image. All these operations must be performed on an eye that is often moving. Therefore, the use of existing fundus cameras requires a significant amount of training and skill; even the most skilled operators often collect a large number of images of a single eye in order to select one that is of good quality.
In existing fundus cameras, alignment and focusing are performed under visual control by the operator. This usually requires that the patient's eye be brightly illuminated. Such illumination would normally cause the pupils to constrict to a size too small to obtain good images. Therefore, most existing fundus cameras require that the patient's pupil be dilated by drugs.
U.S. Pat. No. 4,715,703 describes an invention made by one of the present inventors and discloses apparatus for analyzing the ocular fundus. The disclosure in this patent is incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention is in the nature of a fundus camera which automatically and quickly performs all the aligning and focusing functions. As a result, any unskilled person can learn to obtain high quality images after only a few minutes of training and the entire imaging procedure requires far less time than existing fundus cameras. Moreover, all of the automatic aligning and focusing procedures are performed using barely visible infrared illumination. With such illumination, the patient's pupils do not constrict and for all but patients with unusually small natural pupils, no artificial dilation is required. The fundus images can be obtained under infrared illumination and are acceptable for many purposes so that the patient need not be subjected to the extremely bright flashes required for existing fundus cameras. To obtain standard color images using the present invention, it is sometimes necessary to illuminate the eye with flashes of visible light. However, such images can be obtained in a time appreciably shorter than the reaction time of the pupil, so that the pupil constriction that results from the visible flash does not interfere with image collection. Unlike existing fundus cameras, the present invention provides for automatic selection of arbitrary wavelengths of the illuminating light. This facility has two significant advantages. First, it is possible to select illuminating wavelengths that enhance the visibility of certain fundus features. For example, certain near-infrared wavelengths render the early stages of macular degeneration more visible than under white illumination. Second, by careful selection of two or more wavelengths in the near infrared, it is possible to obtain a set of images which, when properly processed, generate a full color fundus image that reveals sub-retinal fundus features. Thus, it is possible to obtain acceptable color fundus images without subjecting the patient to bright flashes.
It is therefore a primary object of the present invention to provide a fundus imager which automatically positions fundus illuminating radiation to enter the pupil while preventing reflection from the cornea from obscuring the fundus image, irrespective of movement of the eye or the patient's head within the head restraint.
Another object of the present invention is to provide automatic focusing of the fundus image based upon the image itself.
Yet another object of the present invention is to provide automatic positioning of one or a sequence of fixation targets to select the sections(s) of the fundus to be imaged.
Still another object of the present invention is to provide a fundus imager for collecting a set of images that can be arranged in a montage to provide a very wide angle fluids image facilitated by the capability of the fundus imager to automatically align and focus the images.
A further object of the present invention is to provide automatic setting of video levels in a fundus imager to use the full range of levels available.
Yet another object of the present invention is to permit aligning and focusing a fundus imager under infrared illumination to permit imaging without drug induced dilation of the pupil.
A yet further object of the present invention is to provide for automatic selection of illumination wavelength.
A yet further object of the present invention is to provide a colored image from a fundus imager by sequential imaging and registration of images.
A yet further object of the present invention is to provide for automatic acquisition by a fundus imager of a stereo image pair having a known stereo base.
A yet further object of the present invention is to provide a head positioning frame for use with a fundus imager.
A yet further object of the present invention is to accommodate for astigmatism and/or extreme near and far sightedness by placing a lens of the patient's glasses in the path of illumination of the fundus imager.
A yet further object of the present invention is to provide a method for automatically positioning the illuminating radiation of a fundus imager to prevent corneal reflections from obscuring the fundus image obtained.
A yet further object of the present invention is to provide a method for automatic focusing in a fundus imager.
These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:
FIG. 1 is a schematic diagram illustrating the functional elements of the present invention and FIG. 1 a representatively illustrates structure for moving the optical system;
FIGS. 2A and 2B illustrate representations of the front and side views of apparatus for focusing the image;
FIGS. 2C and 2D illustrate representations of the front and side views of a variant apparatus for focusing the image;
FIG. 3 is a block diagram illustrating a representative computer system for operating the present invention;
FIG. 4 illustrates the effect of corneal reflections to be avoided;
FIG. 5 is a schematic illustrating an alignment of the optical axis to avoid corneal reflections;
FIGS. 6 is a graph illustrating determination of an acceptable video level;
FIG. 7 illustrates determination of edge points;
FIGS. 8A , 8 B and 8 C depict the light rays from a point to an image plane without an interposed aperture, and with an interposed aperture at two locations displaced from one another;
FIGS. 9A and 9B illustrate the shift of an image upon an image plane located beyond the focal plane in response to displacement of an interposed aperture from one location to another;
FIGS. 10A and 10B illustrate the shift of an image upon an image plane located short of the focal plane in response to displacement of an interposed aperture from one location to another; and
FIG. 11 illustrates a head restraint in the form of a pair of spectacles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , there is illustrated a preferred embodiment of optical system 10 of the present invention. Lens L 1 focuses light from a light source S onto a small aperture A 1 . The light source may be a source of visible light, infrared radiation or of a wavelength in the near visible infrared region. Light passing through aperture A 1 passes through a filter F toward lens L 2 . Lens L 2 collimates (makes parallel) light from aperture A 1 . A beam splitter BS 1 reflects about ninety percent (90%) of the incident light from lens L 2 to lens L 3 . Half of the light passing through lens L 3 is transmitted through beam splitter BS 2 and is absorbed by light trap LT. The other half of the light passing through lens L 3 is reflected by beam splitter BS 2 and forms an image of aperture A 1 in the focal plane of lens L 3 , which focal plane lies in the plane of a patient's pupil P. The light passing through the pupil illuminates a section 12 of ocular fundus 14 (hereinafter only the term fundus will be used).
Light diffusely reflected from fundus 14 emerges from pupil P and half of it is transmitted through beam splitter BS 2 toward collimating lens L 4 , which lens is at its focal distance from the pupil. If the patient's eye is focused at infinity, the light reflected from each point on fundus 14 will be collimated as it is incident on lens L 4 . Therefore, the 50% of the light that passes through beam splitter BS 2 will form an aerial image of the fluids in the focal plane of lens L 4 , which focal plane is represented by a dashed line identified as FI (Fundus Image). The light passes through lens L 6 , which lens is at its focal distance from fundus image FI. Thus, lens L 6 will collimate light from each point on the fundus. Further, because the light considered as originating in the plane of pupil P is collimated by lens L 4 , lens L 6 will form an image of the pupil in its back focal plane, which is coincident with the location of second aperture A 2 . Light passing through second aperture A 2 is incident on lens L 7 , which lens will then form an image of the fundus in its back focal plane which is coincident with an image sensor or video sensor C 1 . The video image produced by video sensor C 1 represents an image of the fluids.
An infrared light emitting diode (LED), representatively shown and identified by reference numeral 21 , diffusely illuminates the region of the front of the eye.
If the eye is not focused at infinity, the aerial fundus image FI will be moved away from the back focal plane of lens L 4 . For example, if the eye is nearsighted, the aerial fundus image will move toward lens L 4 . Such movement would cause the fundus image to be defocused on video sensor C 1 . Focusing the image under these conditions is accomplished as follows. Lens L 6 , aperture A 2 , lens L 7 , and video sensor C 1 are mechanically connected to one another by a focusing assembly labeled FA; that is, these elements are fixedly positioned relative to one another and move as a unit upon movement of the focusing assembly. A unit identified by reference numeral 23 provides rectilinear movement of the focusing assembly on demand.
The entire optical system ( 10 ) discussed above and illustrated in FIG. 1 is supported upon an assembly shown in FIG. 1 a and identified by reference numeral 20 . The assembly includes motive elements, such as rectilinear actuators and related servomechanisms responsive to commands for translating the entire optical system horizontally (laterally), vertically and toward and away from the eye, or movement in the x, y and z axis as representatively depicted by set of arrows 22 . By moving the assembly as necessary in the x, y and z axis the illumination light is positioned on the eye.
To operate optical system 10 , a computer control system 30 is required, which is representatively illustrated in FIG. 3 . The computer control system includes a central processing unit (CPU) 32 , such as a microprocessor, and a number of units interconnected via a system bus 34 . A random access memory (RAM) 36 , a read only memory (ROM) 38 are incorporated. An input/output adapter 40 interconnects peripheral devices, such as a disk storage unit 42 . A user interface adapter 44 connects the keyboard 46 , a mouse (or trackball) 48 , a speaker 50 , a microphone 52 , and/or other user interface devices, such as a touch screen (not shown) with system bus 34 . A communication adapter 54 interconnects the above described optical system 10 through a communication network 56 . A display adapter 58 interconnects a display unit 60 , which maybe a video screen, monitor, or the like. The computer operating system employed maybe any one of presently commercially available operating systems.
In operation, an operator enters patient information data into the computer control system using the keyboard and also enters the location or set of locations on the fluids that is/are to be imaged. It may be noted that the field of view of the optical system is preferably 30° in diameter while the ocular fundus is about 200° in diameter. To image various regions of the 200° fundus, the eye can be rotated with respect to the optical system; such rotation is achieved by having the patient look from one reference point to another. After entry of the raw data, the patient's head is juxtaposed with a head positioning apparatus to locate the eye in approximate alignment with respect to the optical axis. An image of the front of the eye produced by a video sensor or camera CAM, ( FIG. 1 ) appears on computer-screen 60 . The operator may use a trackball or mouse 48 or similar control to move the image horizontally and vertically until the pupil is approximately centered on a set of cross-hairs displayed on the computer screen. Such horizontal and vertical movements, along with focusing of the image of the pupil, are achieved by moving entire optical system 10 through energization of assembly 20 (see FIG. 1 ). That is, the horizontal and vertical movements of the image are achieved by moving the entire optical system horizontally and vertically and the focusing of the pupil image is accomplished by moving the entire optical system toward or away from the eye. When the operator is satisfied that the pupil is approximately centered, the operator de-energizes LED 21 (which illuminated the front of the eye) and then initiates the automatic alignment and image collection procedure.
To achieve proper alignment of the optical system with the eye requires that the light from light source S enter the pupil. Initially, the angular position of beam splitter BS 1 is set so that the image of aperture A 1 lies on the optical axis of the system. It is noted that the image of aperture A 1 contains the light used to illuminate the ftndus. If the operator has initially centered the pupil image even crudely, light from light source S will enter the pupil. About two percent (2%) of the light incident on the eye will be reflected from the corneal surface and if this light reaches video sensor C 1 , it would seriously obscure the image of the fundus. Therefore, the optical system includes the following elements for preventing corneal reflection from reaching video sensor C 1 .
If the light rays forming the image of aperture A 1 were aligned so that the central ray were perpendicular to the corneal surface, then many of the rays in the corneal reflection would pass backward along the incident light paths. As shown in FIG. 4 , the central ray would pass back on itself; the ray labeled Ray- 1 would pass back along the path of the incident ray labeled Ray- 2 , etc. (The angle at which a ray is reflected from a shiny surface can be determined as follows. First, find the line that is perpendicular to the surface at the point that the ray hits. Then find the angle between the incident ray and the perpendicular ray; this is called the “angle of incidence”. Finally, the ray will be reflected at an angle equal to the angle of incidence but on the other side of the perpendicular line. This is called the angle of reflection.) It is therefore evident from the schematic shown in FIG. 4 that many rays reflected from the corneal surface and impinging upon beam splitter BS 2 would enter lens L 4 and impinge upon video sensor C 1 .
However, the corneal surface is steeply curved and if the central ray of the incident light is moved far enough away from the perpendicular to the cornea, as shown in FIG. 5 , the reflected light will be deflected far enough to miss beam splitter BS 2 and therefore miss passing through lens L 4 and therefore not impinge upon video sensor C 1 . The method for achieving this deflection will be described below.
Initially, the angle of beam splitter BS 1 ( FIG. 1 ) is set so that the image of A 1 lies on the optical axis. Thereby, the optical system is automatically aligned to be centered on the pupil and the image of A 1 is in the plane of the pupil, as set forth below. When this alignment is accomplished, the image A 1 will be centered on and in focus in the plane of the pupil.
If a fundus image were to be collected under these conditions, the reflection from the cornea would severely spoil the fundus image. To prevent this, after alignment is achieved, the angular position of beam splitter BS 1 is changed by motor 24 and linkage 26 to move the image of A 1 to the bottom of the pupil. If the pupil is about 4 mm or larger in diameter, this will deflect the corneal reflection sufficiently that it will not enter lens L 4 . To do this, the diameter of the pupil must be known. This diameter is determined by performing the method described below for automatic alignment in the vertical and horizontal directions.
If the pupil is relatively small, a further technique is employed to allow greater displacement of the illumination away from the center of the pupil. This is accomplished by automatically changing the aiming point of the vertical alignment servo so that the image of the pupil moves downward with respect to the optical axis by an amount that is a fixed proportion of the pupil diameter. Thus, the regions of the pupil through which the images are collected moves toward the top of the pupil and the image of A 1 has more room to move downward. This description refers to movement of the image of A 1 to the bottom of the pupil. The same effect can be achieved by moving the bar to the top of the pupil and moving the servo aiming point so that the pupil image moves upward. In general, if the patient is looking downward, moving the image of A 1 downward is more effective and if the patient is looking upward, it is more effective to move the image of A 1 to the top of the pupil.
A method for tracking the pupil and positioning the image of aperture A 1 on the pupil of the eye will be described hereafter with reference to FIG. 1 . The images appearing on video sensors or cameras CAM 1 and CAM 2 are used for automatic tracking of the eye and the positioning of the image of aperture A 1 . This is done by using the computer system and its software for extracting the edges of the pupil from the video signal and computing the coordinates of its center and of its edges.
About half of the light reflected from fundus 14 is reflected from beam splitter BS 2 through lens L 3 , and about 10% of that light passes through beam splitter BS 1 . Some of that light passes through a lens L 8 and falls on a small camera CAM 1 on which an image of the pupil is formed. Others of those rays pass through another lens L 9 (shown in dashed lines) and to camera CAM 2 (shown in dashed lines) and forms another image of the pupil. These lenses and cameras are placed one above and the other below the plane of the paper in FIG. 1 . Thereby, one camera receives the image of the pupil as seen at an angle to the left of the optical axis and the other camera receives the image of the pupil as seen at an angle to the right of the optical axis.
The output of one of these cameras is used to position optical system 10 in the x and y axis, as described in further detail below. To position the optics at the correct distance from the eye (the z direction), the images from cameras CAM 1 and CAM 2 are compared in software. When the pupil is at the correct distance from the optics, that is, when the pupil is in the focal plane of lens L 3 (and therefore, because of the mechanical arrangement, in the focal plane of lens L 4 ), then the two pupil images will lie in a particular relationship to each other. If the optical system were perfectly aligned and centered, the two images would each be perfectly centered in the fields of view of their respective cameras CAM 1 and CAM 2 . Then, considering the fields of view of the two cameras as superimposed, if the pupil image from the left camera is to the left of the image from the right camera, then the optics need to be moved closer to the patient and vice versa.
If the optical system is not perfectly aligned, there will be a particular relative positioning between the two images that occurs when the pupil is in the correct position, and the software drives optical system 10 in the z direction until that relative position is attained. (That relative position is determined during the procedure for optically aligning the entire system.)
A method for finding the center and the edges of the pupil image will now be described. It involves finding the edges of the pupil image on each video line that intersects the edges and then computing the most likely position of the center and of the edges of the actual pupil. The image from camera CAM 1 is read out, as is the standard video practice, by reading the values of the various points along a horizontal line and then the values along the next horizontal line, etc. (neglecting the detail of interlacing). If a given video horizontal line intercepts the image of the pupil, the video level will abruptly rise from the dark background level to the brighter level of the pupil. To locate this transition and find the position of each edge, it is necessary to define the values of the background and of the pupil. To do this, a histogram of pixel values is formed during the first few video frames. It will contain a large peak with values near zero, representing dark background pixels, and additional peaks at higher values that represent the pupil and various reflections to be discussed below. A typical histogram is illustrated in FIG. 6 . Each point along the horizontal axis represents a different video signal level and each point on the vertical axis indicates the area of the image that displays the corresponding video level.
The “background level” is defined as the level just below the first minimum. Specifically, the histogram is first smoothed using a running block filter. That is, for a position on the horizontal axis the vertical value on the curve is replaced by the average of the vertical value and its adjoining values. This computation is performed in steps along the horizontal axis (video level) until there are ten consecutive values for which the vertical axis increases. The “background value” is then defined as the lowest of these ten values. An “edge point” on each horizontal line is defined as the horizontal location for which the video level changes from equal to or below the “background value” to above that value or changes from above that value to equal or below that value. As the video scan proceeds, the location of each point is saved. Thus, at the end of each video frame, a set of point locations is stored in the computer memory (see FIG. 3 ).
If the pupil image consists solely of a bright disk on a dark background, the above described procedure would essentially always be successful in finding a close approximation to the actual pupil edges. However, for real pupil images the procedure is confounded by two sources of reflections. First, light reflected from the cornea; if this light reaches cameras CAM 1 and CAM 2 , it will form a bright spot superimposed on the pupil image. If that spot were entirely within the margins of the pupil, it would not interfere with the process described above. However, if it falls on the edge of the pupil image, as it may when a patient is looking at an angle to the optical axis of the optical system, then it will appear as a bulge on the edge of the pupil, as illustrated in FIG. 7 . Therefore, some of the “edge points” located by the above computations will actually be edges of the corneal reflection instead of the edge of the pupil. Second, a similar problem arises if the image of aperture A 1 falls on the edge of the pupil, as it might during an eye movement too fast to be accurately tracked and compensated. In that event, finding the center and the edges of the pupil requires special procedures.
One such special procedure will described below. The edge points are collected as described above. There will typically be several hundred such points. An ellipse is then found (determined) that best fits the set of edge points. The pupil of the human eye is usually circular, but if it is viewed from an angle, as it will be if the patient is looking at a point other than on the optical axis, then the image of the pupil will approximate an ellipse. So long as the reflections from the cornea and iris do not overlap a major part of the pupil edge (and so long as the pupil is not of grossly abnormal shape), such a procedure yields a good estimate of the locations of the actual pupil center and the edge.
One method for finding the best fitting ellipse will be described. Assuming that two hundred points have been labeled edge points by the above procedure, each of such points has a horizontal (x) and a vertical (y) location. Assume that these two hundred points, that is pairs of values (x,y), are in a consecutive list. Five points are selected at random from the list, requiring only that each selected point be separated from the next selected point by at least ten positions on the list. This process will then yield the locations of five putative edge points that are some distances apart on the pupil. These five pairs of values are substituted into the equation for an ellipse and solved for the five ellipse parameters. One form of equation for an ellipse is:
c 1* x ^2 +c 2* xy+c 3* y ^2 +c 4* x+c 5* y =1
Substitute the five putative edge points as the pairs (x,y) of values in that equation. Invert the matrix to find the values for c 1 through c 5 . Then the angle that the ellipse makes with the xy axis is:
θ=½*arc cot(( c 1− c 3)/ c 2)
Then if u=x*cos θ+y*sin θ and v=−x*sin θ+y*cos θ, then d 1 *u^2+d 3 *v^2+d 4 *u+d 5 *v=1
Where d 1 =c 1 *cos^2+c 2 *cos θ*sin θ+c 3 *sin^2 θ
d 3= c 1*sin ^2 θ−c 2*cos θ*sin θ+ c 3*cos ^2 θ
d 4= c 4*cos θ+ c 5*sin θ
d 5=− c 4*sin θ+ c 5*cos θ
The center of the ellipse has u coordinate u=−d 4 /(s*d 1 ) and v coordinate V=−d 5 /(2*d 3 ) so the center of the ellipse has the x coordinate
x=u *cos θ− v *sin θ
and the y coordinate
y=u *sin θ+ v *cos θ
If R=1+d 4 ^2/2d 1 +d 5 ^2/2d 3 then the semiaxes of the ellipse have lengths
Square root (R/d 1 ) and square root (R/d 3 )
This entire procedure is repeated, say, 100 times for 100 different sets of putative points yielding 100 different estimates of the x,y location of the center. The best fitting ellipse is the one for which the center is closest to the median x and y values of the set of 100.
The resulting deviations between the horizontal and the vertical locations of the center of the chosen ellipse and the optical axis of the optical system can be used directly as error signals to drive the positioning servos associated with assembly 20 ( FIG. 1 a ) and the image of aperture A 1 can be directly and finely positioned so that the image lies just inside the pupil.
An automatic method for focusing the ftndus image will be described with reference to FIG. 2 a and 2 b showing an assembly 70 . Aperture A 3 and A 4 are holes significantly smaller then the image of the pupil and which is conjugate with the pupil; that is, they are in the same plane as the image of the pupil but offset laterally and vertically. In the preferred embodiment, apertures A 3 , A 4 are circular apertures two millimeter (2 mm) in diameter. Apertures A 3 and A 4 are mounted on subassembly 74 coupled to a linear actuator 72 that can move the subassembly rapidly in a vertical direction, as depicted by arrows 75 . Subassembly 75 lies in the plane of A 2 (see FIG. 1 ) and representatively identified by a box labeled 77 . In the alignment method described above, the image of aperture A 1 is made to lie near the edge of the pupil and a fundus image is saved. To focus, two images are saved in rapid succession, one with aperture A 4 lying to the right of the center of the pupil image and the second with aperture A 3 lying to the left of the center of the pupil image, by enabling linear actuator 72 to rapidly translate plate 76 . If the focusing assembly FA is positioned so that the fundus image FI lies in the focal plane of lens L 6 (the fundus image is thus correctly focused on video sensor C 1 ) then the two images taken with apertures A 3 and A 4 in the two positions will be in registry and superimposable. However, if focusing assembly FA is not correctly positioned and the image is out of focus, then one of the images will be horizontally displaced with respect to the other. With the particular optical arrangement illustrated in FIG. 1 , the direction of the displacement (unit 23 , arrow 25 ) indicates the direction that focusing assembly FA must move to achieve correct focus and the size of that displacement is directly proportional to the distance the focusing assembly must move to correct focus.
To explain more clearly the direction of displacement of the focusing assembly (FA) to achieve correct focus, joint reference will be made to FIGS. 8A , 8 B, 8 C, 9 A, 9 B, 10 A and 10 B. As shown in FIG. 8A , lens Lx forms an image of a point P that is sharply focused on image plane IP. If the aperture of an apertured plate Ax is placed between point P and lens Lx off the optical axis, the image of point P will be in focus on image plane IP, as shown in FIG. 8B . However, because certain of the-rays are excluded by the plate, the intensity of the image on the image plane will be reduced. As depicted in FIG. 8C , displacement of the aperture in apertured plate Ax will have no effect upon the location of the image of point P on the image plane. If the image plane IP is displaced from the focal plane FP, as depicted in FIG. 9A , a blurred image of point P will appear on the image plane at a location diametrically opposed relative to the optical axis from the aperture in apertured plate Ax. When the apertured plate is displaced (like the displacement shown in FIG. 8C ), the blurred image on the image plane will be displaced in a direction opposite from the displacement of the apertured plate, as shown in FIG. 9B . If image plane IP is short of the focal plane FP, as shown in FIG. 10A , the rays passing through the aperture of apertured plate Ax will form a blurred image of point P on the image plane. This blurred image will be on the same side of the optical axis as is the aperture. If the apertured plate is displaced (like the displacement shown in FIG. 8C ), the blurred image of point P on the image plane will be displaced in the same direction, as shown in FIG. 10B . From this analysis, the following conclusions are evident. If the image is in focus on the image plane, any shift of an apertured plate will not affect the position of the image in the image plane. If the image plane is beyond the focal plane, the image on the image plane will shift in a direction opposite to the direction of displacement of the aperture. Congruously, if the focal plane is beyond the image plane, the image on the image plane will shift in the same direction as the aperture is displaced. From these relationships, it is a simple computational exercise performable by the computer system illustrated in FIG. 3 to determine the direction and amount of displacement of focal assembly FA necessary to place the image of the fundus in focus on video screen C 1 .
Thereby, automatic focusing is achieved by finding the displacement of one image of a pair of images that is required to bring the two images into registry and then moving the focusing assembly in accordance with such result. The required displacement can be found by computing a cross-correlation function between the two images. This is a mathematical computation that, in effect, lays one image on top of the other, measures how well the two images correspond, then shifts one image horizontally a little with respect to the other, measures the correspondence again, shifts the one image a little more and measures the correspondence again and repeats these steps for a large number of relative positions of two images. Finally, the shift that produces the best correspondence is computed.
Even when a patient is trying to hold his/her eye steady, the eye is always moving and as a result the fundus image is continually shifting across the sensing surface of video sensor C 1 . Exposure durations for individual images are chosen to be short enough (about 15 milliseconds) so that this motion does not cause significant blur. Nevertheless, the time interval between members of pairs of images taken during the automatic focusing procedure may be long enough to allow movement between the images that would confound the focusing algorithm. Therefore, the actual procedure requires that a number of pairs of images be collected and, only when two members of a pair agree will they be used as the measure of focus error.
The focusing method described above requires that a number of image pairs must be collected in order to find a set that is relatively unspoiled by eye movements. It would be preferable to obtain the two images (one through the left and the other through the right side of the pupil) simultaneously, so that eye movements would not affect the result. A method for simultaneous image collection is described below.
FIG. 2A illustrates of an assembly 70 that lies approximately in the plane of aperture A 2 shown in FIG. 1 and mounted on the focus assembly FA (representatively identified as box 77 ). FIG. 2A shows a view of assembly 70 from the patient's side of the optical system and FIG. 2B is a representative top view of the assembly. A linear actuator 72 moves a subassembly 74 , as represented by arrow 75 , up or down. The subassembly consists of an opaque plate 76 with two round apertures, labeled A 3 , A 4 and a pair of mirrors 78 , 80 . In one position of the subassembly, one (A 3 ) of the two apertures lies just to the left of the optical axis and in another position, the other aperture (A 4 ) lies just to the right of the optical axis. Those are the two positions described above for collecting images through the right and left sides of the pupil.
If subassembly 74 is moved farther upward by linear actuator 72 , the image of the patient's pupil will fall on double mirrors 78 , 80 . In a preferred embodiment, the double mirrors are formed by a right angle prism 82 with the two faces ( 78 , 80 ) that form a right angle being silvered. When the mirrors are in place, light from the fundus that exits through the left side of the pupil is deflected through a lens L 8 and onto a video sensor or camera, CAM 3 , and light from the right side of the pupil is deflected through another lens L 9 and to another video sensor or camera, CAM 4 . When the fundus image is in proper focus, light from the fundus will be collimated when it arrives at each of lenses L 8 , L 9 and, because cameras CAM 3 and CAM 4 lie in the focal planes of those lenses, an image of the fundus will be formed on each camera, one of the images being formed with light passing through the left side of the pupil and the other is formed with light passing through the right side of the pupil. The two cameras are synchronized so that the two images are captured simultaneously.
If the fundus is in correct focus, and if the two lenses (L 8 , L 9 ) and two cameras (CAM 3 , CAM 4 ) are perfectly positioned on the optical axes, then the two images will occupy identical positions on the two cameras. If the image is out of focus, the two images will move in opposite directions with respect to their respective cameras. Thus, computing a cross-correlation function on the two images provides the information necessary to move the focus assembly FA to achieve correct focus, (by the same principle as explained with reference to FIGS. 8 , 9 and 10 ). Because the two images were collected simultaneously, eye movements cannot perturb the measurement.
FIGS. 2C and 2D show another method for obtaining images from the two sides of the pupil simultaneously. FIG. 2C is a side view of an assembly 90 much like assembly 70 shown in FIG. 2A and is placed in the same position (box 77 in FIG. 1 ) in the plane of the image of the pupil. The two upper holes A 5 , A 6 are, again, the holes for imaging the fundus through the right (A 6 ) and left (A 5 ) sides of the pupil for stereo imaging. When subassembly 92 is raised by linear actuator 94 (as represented by arrow 95 ) to cause the image of the pupil 84 to fall symmetrically on two lower holes A 7 , A 8 , one hole lets through light from the fundus that passes through the top of the pupil and the other through the bottom of the pupil. A wedge prism 96 is placed over top hole A 7 and right angle prism 98 or dove prism is placed over lower hole A 8 , as shown in FIG. 2D . Light passing through the two holes (A 7 , A 8 ) and prisms 96 , 98 falls on lens L 7 (shown in FIG. 1 ) and forms fundus images on video sensor C 1 .
If the prisms were removed and the fundus were in good focus, the images through the top and bottom holes would be precisely superimposed, but if the image is out of focus, one image would move up and the other down, in proportion to the degree of defocus. If that displacement could be measured, it would serve as the error signal to perform automatic focusing of the fundus image. However, because the two images would strongly overlap, there is no simple way to distinguish one image from the other. The prisms serve the function of moving the two images so that they do not overlap, as follows.
Upper wedge prism 96 deflects all of the rays 100 passing through it upwards, 15 degrees in the preferred embodiment. Therefore, the fundus image formed through the top of the pupil will move upwards on the camera. This will cause the top half of the image to fall above the sensor surface and be lost. However, the bottom half of the image will fall on the top half of the sensor and can be captured since the field of view is 30 degrees.
Right angle prism 98 acting as a dove prism, performs two different functions. First, because hypotenuse side 102 of the prism is not horizontal but is tilted downward, the image (ray 104 ) passing through it will be deflected downward by 15 degrees. If this were its only action, it would cause the upper half of the fundus image to fall on the lower half of the sensor. Therefore the two images, being different parts of the fundus, could not be compared. However, its dove prism action causes the image passing through it to be rotated through 180 degrees (as depicted by ray 104 ), so that the bottom half of the fundus image falls on the bottom half of the sensor. That allows relative positions of the two images (and thus the focus error) to be computed. In this way, the focus error can be determined from (half) images collected simultaneously.
Of course, if the two lower holes (A 7 , A 8 ) were side by side instead of one above the other, and the prisms were rotated accordingly, the two half images would be positioned one on the left and the other on the right half of the sensor, and the computation for focus error could again be accomplished.
Selection of the fluids region to be imaged will now be described. Adjacent beam splitter BS 1 illustrated in FIG. 1 lies a set of dots 15 , 16 , 17 , 18 and 19 . Each dot represents a visible light emitting diode (LED). Beam splitter BS 1 transmits about 10% of the light from these LED's toward lens L 3 and the eye. The set of dots lies in the back focal plane of lens L 3 and these LED's appear to the eye as if they were a long distance away. Only one of the LED's is illuminated at any given time and the patient is asked to look at it. When the patient looks at the illuminated LED, the location of the LED with respect to the optical axis of the instrument determines the location on the fundus that will be illuminated and imaged. For example, if the LED that lies on the optical axis is turned on and the patient fixates it, then the image will be centered on the fovea or macula. If the illuminated LED is 17 degrees (17°) to the patient's left, then the region of the ftndus imaged has its center 17 degrees (17°) to the left of the macula (as observed from the front of the eye).
In addition to the LED's in the plane labeled FIX, other visible LED's, such as LED 28 shown in FIG. 1 , are positioned at various angular displacements from the optical axis, lying, such as to the side of lens L 4 . When one of these LED's is turned on, it does not appear at optical infinity but nevertheless the patient can successfully fixate it to yield a view of more peripheral fundus features.
When the operator sets up the instrument prior to collecting images, he/she selects the region or set of regions of the fundus to be imaged. If just one region is to be imaged, the appropriate LED will be lighted. If a series of locations is to be imaged, the computer (see FIG. 3 ) automatically selects the LED corresponding to the first location; after the image has been collected, the remaining selected LED's are lighted in sequence until the desired sequence of images has been obtained. If such a sequence involves locations that are widely separated so that the patient must make a significant eye movement to refixate, then the computer commands the horizontal and vertical positioning servo mechanisms of assembly 20 ( FIG. 1 a ) to move optical system 10 (and optical axis) to the position where the center of the pupil is expected to be after the fixation movement.
After the image of aperture A 1 has been located to exclude the corneal reflection and focusing has been achieved, another pair of images is collected with aperture A 2 in each of two positions. This pair of images constitutes a stereo pair of images with a known stereo base, which base is the distance through which aperture A 2 has moved.
During the alignment and focusing procedures previously described, filter F (see FIG. 1 ) blocks visible light but transmits near infrared wavelength radiation. To obtain an image or set of images in infrared illumination, this filter need not be changed. For certain forms of colored images, it is necessary to collect an image, change the filter to one transmitting a different wavelength band, acquire another image and return the infrared filter. The result is two or more images, each taken in a different wavelength band. To display a single color image, the different images are used to drive different color guns in a display device. For example, if one image is collected in red illumination and a second is collected in green illumination then the red image is made to drive the red gun in the display device and the green image is made to drive the green gun in the display device. The combined images will appear as a normal (two color) image.
During the interval between images collected in different wavelengths, it is possible that the eye, and thus the fundus image, will move significantly. If such movement occurs, then the variously colored images would not be in registry when displayed. To prevent this occurrence the images are automatically registered before being displayed by performing a two-dimensional cross-correlation and then shifting the images in accordance with the result.
Essentially all standard ophthalmic instruments position a patient's head using a combination of a chin rest and a forehead rest. Other devices, such as a combination of chin rest and support for the bridge of the nose would be suitable. Typically, only a bridge of the nose rest is used in the present device. These types of devices are representatively shown in FIG. 1 by box 13 . The variations in the location of the eyes with respect to the bridge of the nose is such that virtually all eyes will fall within a cube that is fixed with respect to the instrument and is about 20 millimeters on a side. This is a much smaller variation then is encountered by using the usual chin and forehead rest apparatus. Thus, the commonality and uniformity of the location of the eyes with respect to the spectacles or nose bridge requires a very small range of accommodating movement of optical system 10 . Furthermore, a properly chosen device constrains head movement appreciably better than a chin and forehead rest apparatus; thus, the requirement for an automatic tracking system is reduced.
The motion of focusing assembly FA (see FIG. 1 ) compensates for a patient's spherical refractive error (near or farsightedness) but does not correct for astigmatism. Because the fundus images are collected through a small aperture A 2 , moderate amounts of astigmatism will not significantly spoil the image quality. If a patient has a strong astigmatism, correction is desirable. In principle, this correction could be achieved by allowing the patient to wear his/her glasses in the instrument. However, the reflections from such eyeglasses may seriously impair the image quality. An equivalent result which does not create serious reflections is that of mounting the patient's eyeglasses in the optical system in a plane close to the plane of aperture A 2 with the same orientation as when worn. A representative mounting 29 for receiving and retaining a lens of a pair of glasses is shown in dashed lines in FIG. 1 .
Color images are always composed of what can be considered as separate images taken in each of a number of wavelength bands. In the present invention, the bands are. chosen by selecting filters (such as filters F, F 1 shown in FIG. 1 ). When the fundus is illuminated with green light, the resulting images show the superficial features of the retina clearly because green light is either reflected from the superficial features or if it is not reflected, it is completely absorbed. When the fundus is illuminated with red or near infrared light, the light passes through most of the superficial features and is reflected from deeper ones. Thus, images in green light reveal some of the nerve tissue of the retina and the blood vessels that nourish those tissues, while images in red illumination reveal the subretinal (choroidal) vessels that nourish the deeper layers.
It is standard procedure in fimdus imaging to display black and white images taken in green and in red light to reveal these different features and also to combine those images to form a single color image. Through software and manipulation of a mouse a technique has been implemented that presents these images in an interesting and useful way as set forth below.
The computer screen 60 ( FIG. 3 ) that displays the fundus image includes a mouse ( 48 ) controlled computer generated (CPU 32 ) slider. When the slider is at one end of its travel, the red light image is displayed as a black and white image. At the other end, the green light image is displayed as a black and white image. Between those two positions, the two images are superimposed by having the red image drive the red gun of the display and the green image drive the green gun. As the slider moves from the red light end toward green light end, the intensity of the red image diminishes and the intensity of the green one increases. In this way, as the slider moves, the image changes as if the depth of the view of the fluids were changing. The selective change in image can be accomplished when viewing the images in stereo as well.
When a fundus image is displayed, a small image of the pupil that was taken at the same time as the fundus image is also displayed. The pupil image has drawn upon it indications of which parts of the pupil were used to collect the images (that is, which parts of the pupil were imaged on the two positions of holes A 3 , A 4 or A 5 , A 6 in FIG. 2A and 2C , respectively). In this way, the operator can judge whether or not, for example, the patient's eye lids partially obscured the optical paths, whether or not eye lashes might have interfered, etc. This is particularly useful when the fundus image appears poor, because it often informs the operator about what needs correction.
If the eye being imaged has a cataract that lies in the relevant optical path, the fundus image can be spoiled. The way in which the pupil image is formed in the cameras, ( FIG. 1 , CAM 1 and CAM 2 ) by retro-reflection from the fundus, results in cataracts being visible to the operator. If the operator observes a cataract that will spoil the image, he or she can choose a control option and use mouse 48 to move the aiming point of the alignment servos and thus move the optics with the respect to the eye to try to avoid the cataractous region.
While the invention has been described with reference to several particular embodiments thereof, those skilled in the art will be able to make the various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention. It is intended that all combinations of elements and steps which preform substantially the same function in substantially the same way to achieve the same result are within the scope of the invention.
|
An ocular fundus imager automatically aligns fundus illuminating rays to enter the pupil and to prevent corneal reflections from obscuring the fundus image produced. Focusing the produced fundus image is automatically performed using a pair of video sensors and is based upon the fundus image itself. A head restraint is used to reduce the gross alignment between the optical system and the patient's pupil.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 35 U.S.C. §371 national stage application of PCT/US2008/086627 filed Dec. 12, 2008, which claims the benefit of U.S. Provisional Patent Application No. 61/013,203 filed Dec. 12, 2007, both of which are incorporated herein by reference in their entireties for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND
A well capable of producing oil or gas will typically have a well structure to provide support for the borehole and isolation capabilities for different formations. Typically, the well structure includes an outer structure such as a conductor housing at the surface that is secured to conductor pipe that extends a short depth into the well. A wellhead housing is landed in the conductor housing with an outer or first string of casing extending from the wellhead and through the conductor to a deeper depth into the well. Depending on the particular conditions of the geological strata above the target zone (typically, either an oil or gas producing zone or a fluid injection zone), one or more additional casing strings will extend through the outer string of casing to increasing depths until the well is cased to its final depth. Each string of casing is supported at the upper end by a casing hanger that lands in and is supported by the wellhead housing, each set above the previous one. Between each casing hanger and the wellhead housing, a casing hanger seal assembly is set to isolate each annular space between strings of casing. The last, and innermost, string of casing extends into the well to the final depth and is referred to as the production casing. The strings of casing between the outer casing and the production casing are typically referred to as intermediate casing strings.
When drilling and running strings of casing in the well, it is critical that the operator maintain pressure control of the well. This is accomplished by establishing a column of fluid with predetermined fluid density inside the well that is circulated down into the well through the inside of the drill string and back up the annulus around the drill string to the surface. This column of density-controlled fluid balances the downhole pressure in the well. A blowout preventer system (BOP) is also used to as a safety system to ensure that the operator maintains pressure control of the well. The BOP is located above the wellhead housing and is capable of shutting in the pressure of the well, such as in an emergency pressure control situation.
After drilling and installation of the casing strings, the well is completed for production by installing a string of production tubing that extends to the producing zone within the production casing. The production tubing is supported by a tubing hanger assembly that lands and locks above the production casing hanger. Perforations are made in the production casing to allow fluids to flow from the formation into the productions casing at the producing zone. At some point above the producing zone, a packer seals the space between the production casing and the production tubing to ensure that the well fluids flow through the production tubing to the surface.
Various arrangements of production control valves are arranged at the wellhead in an assembly generally known as a tree, which is generally either a vertical tree or a horizontal tree. A horizontal tree arranges the production control valves offset from the production tubing and one type of horizontal tree is a Spool Tree™ shown and described in U.S. Pat. No. 5,544,707, hereby incorporated herein by reference for all purposes. A horizontal tree locks and seals onto the wellhead housing but instead of being located in the wellhead, the tubing hanger locks and seals in the tree bore itself. After the tree is installed, the tubing string and tubing hanger are run into the tree using a tubing hanger running tool (THRT) and a locking mechanism locks the tubing hanger in place in the tree. The production port extends through the tubing hanger and seals prevent fluid leakage as production fluid flows into the corresponding production port in the tree.
The tubing hanger typically has a plurality of auxiliary passages that surround the vertical bore associated with the production tubing. The auxiliary passages provide penetration access through the tubing hanger from outside the tree for hydraulic, optical, and electrical components located downhole. Electrical, optical, and hydraulic lines extend downhole alongside the tubing to control and/or power downhole valves such as a surface-controlled subsurface safety valve (SCSSV), temperature sensors, electric submersible pumps (ESP), downhole processors, and the like, as well as possibly provide for chemical reagent injection. Other types of lines than those listed may also be extended downhole. As the tubing hanger is landed and set in the tree, the auxiliary passages in the tubing hanger typically wet mate with auxiliary connectors located in the tree itself that may lead to a control unit mounted to the tree assembly.
A disadvantage of the conventional type of subsea wellhead assembly is that the tubing hanger must be large enough to house the number of passages extending through it. In addition to housing the passages, the tubing hanger requires a certain amount of structural integrity to support the production tubing. Thus there are only so many auxiliary passages that may be included in a given size tubing hanger before the tubing hanger needs to be enlarged. A large diameter tubing hanger also requires a large diameter drilling riser and BOP through which the tubing hanger must be run prior to installing the tree. Additionally, if the tubing hanger is made longer, the tree must also be lengthened, resulting in additional costs and weight for both items.
Another disadvantage of the auxiliary passages is that different wells may require different functions. Thus, trees must be “customized” to meet the needs of the particular well. Whereas certain downhole functionality may be common among many wells, other types of functionality may be more optional. Building a “one-size-fits-all” tubing hanger/tree thus would be inefficient because unwanted functionality built into the tree/tubing hanger adds unnecessary size, weight, and cost to the completion. Manufacturing costs alone would cause inefficiencies because of the added complexity and labor of manufacturing auxiliary ports into a solid tree body.
Another concern is that the downhole functionality needs of any given well may change over the life of the well. Specifically, a well may produce fluids at high pressure during the initial life of the well, but the pressure may taper off in the later part. With the initial higher production, the tree needs to be able to handle pressure as high as 15,000 psi. With such a high pressure, there is usually little need to install an ESP or engineer the capability of powering and controlling the ESP through the tubing hanger because the fluid pressure is adequate for fluid production. However, the pressure may taper off to as low as 5,000 psi during the life of the well and may require the use of an ESP. If so, the entire tree and completion may need to be pulled and replaced to add the ESP capability, thus costing the well operator valuable time and money. The initial tree could be designed for ESP functionality, but would result in a higher initial cost of the tree itself.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the embodiments, reference will now be made to the following accompanying drawings:
FIG. 1 is an embodiment of a function spool installed on a well; and
FIG. 2 shows example auxiliary port connections that may be used in the function spool.
DETAILED DESCRIPTION OF THE EMBODIMENTS
In the drawings and description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. Any use of any form of the terms “connect,” “engage,” “couple,” “attach,” or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.
FIG. 1 illustrates an embodiment of a function spool 10 mounted onto a subsea wellhead 12 . Mounted on the function spool 10 opposite the wellhead 12 , FIG. 1 also shows a horizontal tree 14 . When the well is drilled and ready for completion, the function spool 10 and the horizontal tree 14 are lowered and installed onto the wellhead 12 using hydraulically operated collet connectors 18 , with seals being formed by appropriate gaskets as shown. Although not shown, appropriate valves for controlling fluid production from the horizontal tree 14 are located in or attached to the horizontal tree 14 . Additionally, any suitable connectors may be used instead of the collet connectors 18 . For example, the function spool 10 and horizontal tree 14 may be attached using a bolted flange.
When the well is ready for completion, appropriate plugs are set downhole from the wellhead 12 to maintain fluid pressure. The blowout preventer (BOP) and riser are then removed from the wellhead 12 and the function spool 10 and horizontal tree 14 are installed either in separate sections or both sections at the same time. The BOP and riser are then reattached to the horizontal tree 14 and the plugs removed from the well using an appropriate tool run in through the riser. When installed, the function spool 10 and horizontal tree 14 may then be pressure tested to confirm pressure integrity.
A tubing hanger running tool (THRT) is then used to lower a completion, including a tubing hanger 20 and a string of production tubing 22 , through the riser and land the tubing hanger 20 in the horizontal tree 14 . When landed, the THRT actuates a lock ring 21 at the top of the tubing hanger 20 that engages the horizontal tree 14 and locks the tubing hanger 20 in place. It should be noted though that any locking assembly may be used, such as expandable dogs that engage a corresponding profile in the horizontal tree 14 . The production tubing 22 extends below the tubing hanger 20 into the well and the tubing hanger 20 includes an internal bore 24 aligned on one end with the bore of the production tubing 22 . The other end of the internal bore 24 exits the tubing hanger 20 in alignment with a master production port 26 in the horizontal tree 14 for producing well fluids to the surface. Although not shown, the completion includes a rotational alignment means that aligns the tubing hanger 20 with the horizontal tree 14 for aligning the internal bore 24 with the production port 26 as the tubing hanger 20 is lowered into the set position.
The completion also includes a function mandrel 30 extending from the production tubing 22 below the tubing hanger 20 . As shown, the function mandrel 30 surrounds the production tubing 22 and is held in place by any suitable connection with the production tubing 22 , such as a threaded connection or welding. Instead of being housed in the tubing hanger 20 , the auxiliary function passages are located in the function mandrel 30 to interact with the function spool 10 . Such auxiliary function passages may be located in any position in the function mandrel 30 and may include passages 32 for electrical, optical, and hydraulic lines that extend downhole alongside the production tubing 22 to control and/or power downhole valves such as a surface-controlled subsurface safety valve (SCSSV), temperature sensors, downhole electric submersible pumps (ESP), downhole processors, and the like, as well as possibly provide for chemical reagent injection. Other types of lines than those listed may also extend downhole from the function mandrel 30 .
Corresponding to the functional passages 32 are ports 44 in the function spool 10 that provide access to the function passages 32 from outside the tree for controlling and/or powering the components located downhole. The auxiliary passages 32 typically house connectors that passively wet mate with auxiliary port connectors located in the function spool 10 and may take any suitable form, including vertical or horizontal connectors. The ports 44 in the function spool 10 also include connectors and may also lead to a control unit located subsea or on the surface. Additionally, although the tubing hanger 20 may interact with the horizontal tree 14 to align the radial angle of the tubing hanger 20 and thus the function mandrel 30 , the connection of the function mandrel 30 to the production tubing 22 may be designed to allow a certain amount of function mandrel 30 vertical and rotational movement. The ability of the function mandrel 30 to move allows for a certain amount of tolerance should the connectors not be perfectly aligned when the tubing hanger 20 is in the set position.
As an example, the function spool 10 includes an auxiliary passage 32 for housing a hydraulic fluid line 36 that extends downhole to an SCSSV (not shown). The SCSSV controls the flow of fluid through the production tubing 22 from the producing zone. The fluid line 36 extends from the SCSSV and into the function mandrel 30 and routes into a passive coupler 40 . Corresponding with the coupler 40 in the function mandrel 30 , the function spool 10 includes a vertical coupler 42 that can extend from the function spool 10 into alignment with the function mandrel 30 coupler 40 for a vertical stab connection as shown. The stab connection forms a fluid tight connection when the tubing hanger 20 lands in the horizontal tree 14 . From the coupler 42 , a port 44 extends through the function spool 10 and is accessible from outside the function spool 10 by a hydraulic control line 46 that extends to the surface. When connected, the hydraulic control line 46 enables surface control of the SCSSV for well operations. Alternatively, line 36 may be an electrical line for powering a downhole electric submersible pump (ESP) (not shown).
Also shown in FIG. 1 is an example of another auxiliary passage 32 for housing an electrical line 50 for powering an ESP (not shown). The ESP is used to increase the fluid pressure for production fluids through the production tubing 22 from the producing zone. The electrical line 50 extends from the ESP and into the function mandrel 30 and routes into a passive coupler 52 . Corresponding with the function mandrel 30 coupler 52 is a horizontal coupler 54 that can extend from the function spool 10 into engagement with the passive coupler 52 for a horizontal stabbing engagement as shown. The stab connection thus forms a fluid tight connection between the electrical line 50 and an electrical line 56 located in a port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line 60 that extends to the surface. When connected, the electrical line 50 thus enables surface control of the ESP for well operations. Alternatively, line 50 may be a hydraulic line that extends downhole to an SCSSV (not shown).
The examples shown are simply two possible types of connections that may be made through auxiliary ports in the function mandrel 30 and accessible from the function spool 10 . It should be appreciated that other types of connections may be made as well and that the connections shown in the examples may be used for different types of communication lines, such as for example, electrical, hydraulic, or optical. Additionally, there may be as many auxiliary ports as a given function mandrel 30 may allow. Because the function mandrel 30 is not being used to support the weight of the production tubing 22 , the function mandrel 30 does not require the robust structural integrity of a support body.
With the completion set, the well is ready for production. To create a barrier to fluid from escaping the internal bore 24 through the top of the tubing hanger 20 , plugs 62 are run into the internal bore 24 and set. The BOP and riser may then be removed from the horizontal tree 14 and retrieved. Using the hydraulic control line 36 , hydraulic fluid may be used to open the downhole SCSSV and allow fluid production to flow from the production tubing 22 , and into the production port 26 for flow to the surface or any other desired location.
At different times in the life of the well, the well may need additional or different downhole functionalities. For example, as already mentioned, fluid pressure may initially be adequate for fluid production but a downhole ESP may need to be added for production in the future. Additionally, various downhole sensors or processors may need to be added for ongoing production monitoring and management. With the function spool 10 and function mandrel 30 , the horizontal tree 14 and the tubing hanger 20 need be designed for connecting and supporting the production tubing 22 . The various functional connections are no longer made in the tubing hanger 20 but are instead made using passages in the function mandrel 30 and function spool 10 . The well operators may thus change out the function mandrel 30 and function spool 10 on an as needed basis during the life of the well without having to purchase an entirely new horizontal tree 14 , resulting in considerable cost savings. In addition, the horizontal tree 14 and tubing hanger 20 may be made smaller because they no longer need to house the functional connections, resulting in lower costs. Further cost savings result from a smaller horizontal tree 14 and tubing hanger 20 because of the increased mobility in particular of the horizontal tree 14 itself. With a smaller horizontal tree 14 and separate function spool 10 , the horizontal tree 14 and function spool 10 may now be transported and installed on the wellhead 12 separately using lower capacity cranes without requiring as robust equipment as trees that house all of the functional connections. Further cost savings may also be achieved in manufacturing because instead of each horizontal tree 14 being customized for each well, one horizontal tree 14 may be made for a larger number of wells with the function spool 10 and function mandrel 30 may be customized instead.
An additional benefit also arises for wells that do not require any downhole functionality to be built into a function spool 10 during the initial production of a well. In those cases, no or minimal functionality may be built into the tubing hanger 20 , such as control for an SCSSV, and the horizontal tree 14 may be installed on the wellhead 12 directly. Later in the life of the well, should additional downhole functionality be needed, the function spool 10 and function mandrel 30 may be added at that time, resulting in cost savings for the well operator from being able to continue using the original horizontal tree 14 and not having to install a full function tree for the initial production.
Additional examples of connections through the function mandrel 30 are shown in FIG. 2 that shows the function mandrel 30 engaging a coupling collar 70 and held in place with a capture ring bolted to the bottom of the function mandrel 30 . Extending into an auxiliary passage 32 is an electrical line 76 for powering and/or communicating with a downhole sensor (not shown), such as a pressure transducer. However, any downhole sensor may be suitable. The electrical line 76 extends from the sensor into the function mandrel 30 and ends with a threaded connector 77 that threads into a connector base 78 . The connector base 78 is held in place by an insulated ring 79 and includes a pin contact 80 . Corresponding with the connector, a power connector penetrator 82 is extendable from the function spool 10 into engagement with the pin contact 80 for a horizontal stabbing engagement as shown. The stab connection forms a fluid tight connection between the electrical line 76 and an electrical line in the port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line that extends to the surface. When connected, the electrical line 76 thus enables power of and/or communication with a downhole electronic device, such as a downhole sensor.
FIG. 2 also shows another electrical line 76 for powering and/or communicating with any type of downhole electronic device (not shown), such as a downhole processor. The electrical line 76 extends from the electronic device and into a passage 32 of the function mandrel 30 and ends in a connector base 90 . Extending from the connector base 90 is an electrical contact 92 that extends past a milled portion of the function mandrel 30 . Seals 94 are located in the function mandrel 30 to isolate the milled portion of the function mandrel 30 from fluid pressure in the function spool 10 and flushing ports 96 in the function spool 10 are used to flush the fluid trapped in the milled portion out with appropriate electrical connection fluid. The electrical contact 92 extends into the milled portion and into electrical contact with a contact ring 98 to complete the electrical connection. The contact ring 98 provides a large enough area around the electrical contact 92 that exact placement of the electrical contact 92 with respect to the contact ring 98 is not necessary. Thus, the contact ring 98 does not require exact placement of the function mandrel 30 with respect to the function spool 10 . Although not shown, an electrical line extends from the contact ring 98 in the port 44 that extends through the function spool 10 and is accessible from outside the function spool 10 by an electrical line that extends to the surface. When connected, the electrical line 76 thus enables power of and/or communication with a downhole electronic device, such as a downhole processor.
While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.
|
A production assembly and method for controlling production from production tubing supported by a tubing hanger in a well including a wellhead. The assembly includes a function spool engaged with the wellhead and a tree engaged with the function spool. The tubing hanger is landable in the tree bore such that the production tubing is supported in the well by the tree. A function mandrel separate from the tubing hanger is engaged with the production tubing and positionable inside the function spool bore. The function mandrel includes a passage connected to a line extending into the well that is connectable with a port in the function spool such that communication with a downhole component through the line is allowable from outside the function spool.
| 4
|
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/150,036 filed on Aug. 20, 1999.
FIELD OF THE INVENTION
The present invention relates to a method and apparatus that simultaneously provides both hot and cold DRI (direct reduced iron) from a continuous gravity-fed supply of hot DRI material, as from a conventional direct reduction furnace.
BACKGROUND OF THE INVENTION
Sponge iron, metallized pellets, briquettes, or reduced metal materials such as direct reduced iron (“DRI”), nickel, or the like, are produced by the direct reduction of ores or metal oxides. Large quantities of metallized iron pellets are made in the direct reduction process wherein particulate iron oxide is reduced substantially to metallic iron by direct contact with a reducing gas such as a mixture of hydrogen and carbon monoxide. Throughout this specification and appended claims, the term “metallized pellets” is intended to include metal-bearing pellets such as sponge iron, briquettes, DRI, other compacted forms of reduced metal and the like which contain at least 80 percent of their metal in the metallic state with the balance being primarily in the form of metallic oxide. For these purposes, iron carbide is considered iron in the metallic state. “Metallized” in this specification does not mean coated with metal, but means nearly completely reduced to the metallic state. For ease of discussion and visualization, the majority of this specification will describe the invention as it relates to DRI, although it should be understood that the invention functions equally well with other forms of “metallized pellets” of any size, or any metal.
A problem associated with the use of DRI as a raw material to make steel or other products is its inherent tendency to reoxidize upon exposure to air or water. Exposure of a mass of hot DRI to atmospheric air and moisture causes re-oxidation of the metal (“rusting”) with a significant loss of metallization. The re-oxidation also produces heat that can dramatically raise the temperature of a mass of DRI. The process of reoxidation also releases water-bound hydrogen into the immediate environment. Under proper conditions, hot DRI can ignite the liberated hydrogen resulting in additional heat, formation of additional hydrogen and possibly an explosion within transfer piping or within storage units.
DRI must be removed from a direct reduction furnace in order to be useful. Methods are needed to transport DRI while reducing the risk of re-oxidation. One common method of reducing this risk of re-oxidation is to cool the hot DRI material to a sufficiently low temperature (less than about 100° C.), to prevent the ignition of any hydrogen that is released by the oxidation process. One drawback to this method is that current DRI production systems are typically “all or nothing” propositions with respect to cooling. Either all of the hot DRI material exiting a particular furnace is cooled or none of it is cooled.
A known method of transfer is the pneumatic transfer of hot DRI materials through piping from a furnace to an exterior storage unit. Drawbacks to this method include: extensive piping is required to transfer hot DRI through significant elevation changes, input of additional energy is required to the gases utilized in pneumatic transfer, additional opportunities are present for oxygen intake into transfer piping, and size reduction of hot DRI from nugget-size to particulate-size occurs during the transfer to remote storage units because of abrasion and impact.
The present invention does not employ pneumatic transfer, and instead provides a method and apparatus for removing continuous output of hot DRI material from a direct reduction furnace and gravitationally transferring the output for subsequent processing or storage. The invention may simultaneously provide hot DRI material for subsequent steps such as melting or briquetting. The invention may also cool DRI material for transport, storage, or other use.
The disclosure of the invention refers to elements or components in the Midrex process. The Midrex process and apparatus for direct reduction are disclosed in the following U.S. Patents: U.S. Pat. No. 3,748,120 entitled “Method of Reducing Iron Oxide to Metallic Iron”, U.S. Pat. No. 3,749,386 entitled “Method for Reducing Iron Oxides in a Gaseous Reduction Process”, U.S. Pat. No. 3,764,123 entitled “Apparatus for Reducing Iron Oxide to Metallic Iron”, U.S. Pat. No. 3,816,101 entitled “Method for Reducing Iron Oxides in a Gaseous Reduction Process”, and U.S. Pat. No. 4,046,557 entitled “Method for Producing Metallic Iron Particles”, all of which are hereby incorporated herein by reference.
SUMMARY OF THE INVENTION
The invention is a system for providing both hot and cold DRI from a continuous gravity-fed supply of hot DRI material. The invention is an apparatus for the simultaneous discharge of hot direct reduced iron (DRI) material and cold DRI material from a continuous supply of hot DRI. The invention has a furnace discharge section, a hot discharge section, and a cold discharge section. The furnace discharge section has a pair of discharge outlets for discharging DRI material, and a plurality of feeders. The hot discharge section gravitationally receives hot DRI from the first discharge outlet of the hot discharge cone and conveys the hot DRI through a conduit or pipe to a melting furnace or a hot transport vessel. The cold discharge section gravitationally receives hot DRI material from the other discharge outlet of the furnace discharge section, conveys the DRI to a cooler through a conduit cools the hot DRI, and discharges cold DRI.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide an improved method to simultaneously provide both hot and cold DRI from a continuous supply of hot DRI material.
Another object of this invention is to provide an improved method to simultaneously provide both hot and cold DRI from a continuous supply of hot DRI material, the hot DRI being delivered at a temperature of at least 700° C.
A further object of this invention is to provide apparatus for producing simultaneously both hot and cold DRI from a continuous supply of hot DRI material
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects will become more readily apparent by referring to the following detailed description and the appended drawings in which:
FIG. 1 is front elevational view of a direct reduction furnace with associated feed and discharge apparatus in accordance with the present invention.
FIG. 2 is a front elevational view of a first embodiment of the invention which includes connection of a direct reduction furnace to an electric arc furnace (EAF).
FIG. 3 is a plan view of the first embodiment of the invention which connects a direct reduction furnace to a conventional electric arc furnace (EAF).
FIG. 4 is a front view of an alternative embodiment of the invention which connects a direct reduction furnace to a continuous melting furnace.
FIG. 5 is a plan view of the alternative embodiment of the invention which connects a direct reduction furnace to a continuous melting furnace.
DETAILED DESCRIPTION
The invention is an efficient apparatus and method to simultaneously provide both hot and cold DRI from a continuous gravity-fed supply of hot DRI material, as from a Midrex direct reduction shaft furnace. The invention satisfies the demand for both hot DRI material as a feed to a steelmaking process, and for cool DRI material as a storable commodity for eventual use in a furnace. The transport method thus used throughout this system is gravity, not pneumatics. Since the shaft furnace is elevated, it is possible to discharge into a lower elevation pellet cooler to produce cold DRI and into a lower elevation surge vessel to temporarily store the hot DRI for down stream processing (i.e., for briquetting, melting, etc.). This arrangement provides the unique flexibility for discharging both hot and cold DRI simultaneously. Furthermore, the discharge can be adjusted to produce 100% cold DRI or 100% hot DRI or any combination in between. These adjustments can be made instantaneously without any effect on the process.
Because the present invention avoids the use of pneumatics there is minimal temperature loss of the hot DRI. In fact, hot DRI can be delivered from the surge vessel at a temperature of 700° C. or higher. There is also no loss in metallization since the entire system is sealed and DRI the product is only exposed to reducing or inert atmospheres. Gravity flow also results in negligible product degradation which cannot be avoided during pneumatic conveying. Unlike pneumatics, gravity flow can also handle a wide size range of product (as small as fines and as large as 200 mm).
Referring now to the drawings, and particularly to FIG. 1, the invented apparatus for the simultaneous discharge of hot direct reduced iron (DRI) material and cold DRI material from a continuous supply of hot DRI, such as a continuously discharging DRI furnace 10 , includes a furnace discharge section 12 , a hot discharge conduit 14 , and a cold discharge conduit 16 .
Hot discharge furnace 10 is located above a pellet cooler 20 and above a hot DRI receiving vessel such as surge vessel 30 . The furnace discharge section 12 is generally conical. The furnace discharge section 12 has an upper DRI admitting area 22 and a lower discharge region 24 . The admitting area 22 receives DRI material from the furnace 10 . The material is transported by gravity with the assistance of upper burden feeders 32 , intermediate burden feeders 34 , and lower burden feeders 36 to the discharge region 20 . This embodiment can have a burden discharge feeder 38 , if desired. The burden feeders water are cooled.
The furnace discharge section 12 is a refractory lined cone. The cold DRI discharge rate is controlled by means of a vibratory feeder 26 at the discharge 28 of the pellet cooler 20 .
The first discharge conduit 14 hermetically connects the furnace discharge section 12 to the hot DRI receiving vessel 30 . The second discharge 18 connects the furnace discharge section 12 to the pellet cooler 20 .
Hot discharge conduit 14 is a seal leg having associated degassing and depressuring apparatus. Hot DRI material may be conveyed by the first discharge conduit 24 to a melting furnace. The embodiments of FIG. 2 connects the hot discharge conduit to an electric arc furnace (EAF). However, the invention will work with any melting furnace of sufficient capacity. In addition, the hot DRI material can be transported to a melting furnace by insulated containers sometimes known as “milk cans”, by mechanical conveyors, or the material can be passed through a briquetting machine to form briquettes for transport.
The hot discharge conduit 14 is a sealing and conveying means that differs from the traditional lock hopper-type sealing and conveying means. The sealing and conveying means is a dynamic seal leg, which allows a single, low pressure surge vessel to be used as a receptacle instead of requiring redundant “lock hoppers”.
The hot discharge conduit can discharge hot DRI into a surge bin or surge vessel 30 for temporary storage. The surge bin or surge vessel 30 has an attached bubbler 56 . The bubbler 56 provides an outlet for the seal gas and prevents over pressurization of the vessel 30 . The surge bin or surge vessel 40 has two discharge nozzles 38 that enable quick changeover of the hot transport vessels.
The surge bin or surge vessel 30 is refractory lined. The surge bin or surge vessel 30 has a discharge cone 40 which is preferably made from stainless steel to prevent bridging. A flow stimulator 44 is also located near the discharge of the surge vessel to prevent bridging.
In the cold discharge portion of the apparatus, hot DRI material is conveyed through the cold discharge conduit 16 to a pellet cooler 20 . The DRI material is cooled in the pellet cooler 20 and discharged into an appropriate vessel for storage. The cold discharge conduit 16 is also preferably a dynamic seal leg. The dynamic seal leg isolates the pellet cooler and the inlet of the hot DRI surge vessel which is important because dynamic seal legs eliminate the need for redundant high pressure vessels and feeders in the cooling section, thus reducing the capital investment as compared to that required for similar facilities.
Gas is removed from the cooler pellet through two large off takes 52 located on top of the cooler. DRI Discharge from the cooler is accomplished by a standard DRI discharge mechanism such as vibratory feeder 26 . Preferably the discharge is via a dynamic seal leg 58 beneath the discharge mechanism.
In operation, hot DRI material passes from the furnace discharge section 12 through a sealing and conveying conduit 14 in which the hot DRI is degassed and depressurized. Both the hot discharge conduit 14 and the cold discharge conduit 16 are connected to the furnace discharge section 12 . The product moves by gravity to the cooler (for cold DRI), to a hot transport vessel 60 or to a melting furnace 70 or 72 (for hot DRI).
The hot DRI material that is transported to a melting furnace or a hot transport vessel moves from the direct reduction furnace through hot discharge conduit 14 which is a seal leg. The hot DRI material is conveyed from seal leg 14 to a surge bin or surge vessel 6 or before discharge into a transport vessel melting furnace. The rate of discharge is controlled by the speed of a vertical feed screw 46 at the bottom of the conduit 16 .
The system is shown with hot transport vessel 60 on rails 64 . Two 70- ton transport vessels can fully supply a charge for one EAF heat. Other transport methods such as a hot conveyor or a pneumatic conveyor can be also incorporated into the system.
Hot DRI material that is to be cooled is transported through cold discharge conduit 16 , which may be a seal leg, into pellet cooler 20 in which the pellets are cooled. The cooled DRI material are discharged by vibrator feeder 26 through a cold discharge cone 28 . The discharge rate from the pellet cooler can be changed instantaneously without affecting the process so long as the discharge rate of the furnace remains constant. The rate of discharge is set by a control system.
ALTERNATIVE EMBODIMENTS
The surge vessel arrangement can have various configurations. The surge vessel can be attached to a briquetter. In the configuration shown, a product discharge chamber or a similar device is required upstream to “screen-out” large size product, as is done in an HBI plant.
The apparatus can also utilize a product discharge chamber or a similar device when the hot transport method from the DRI furnace to a meltshop is pneumatic conveying. Pneumatic conveying cannot transport large diameter material (i.e., greater than 200 mm).
When the invention is attached to a conventional EAF, the vertical screw feeder on the inlet of the surge vessel dictates the furnace discharge rate in conjunction with the pellet cooler discharge feeder. When the invention is attached to a hot transport system or to a continuous melting furnace 70 , only one screw feeder is required. Alternatively, screw feeders can be replaced by another device such as a wiper bar.
When the invention is attached to a conventional EAF 72 , a horizontal screw feeder 74 is frequently utilized, which conveys discharged material from the surge vessel to the EAF or to a charging chute 76 . The screw feeder 74 is used because the discharge rate from the surge vessel to the EAF is sporadic. The surge vessel is sized according to the desired EAF heat size.
SUMMARY OF THE ACHIEVEMENT OF THE OBJECTS OF THE INVENTION
From the foregoing, it is readily apparent that we have invented an improved method and apparatus for simultaneously providing both hot and cold DRI from a continuous gravity-fed supply of hot DRI material, the hot DRI being deliverable from a surge vessel at a temperature of 700° C. or higher.
It is to be understood that the foregoing description and specific embodiments are merely illustrative of the best mode of the invention and the principles thereof, and that various modifications and additions may be made to the apparatus by those skilled in the art, without departing from the spirit and scope of this invention, which is therefore understood to be limited only by the scope of the appended claims.
|
A method and apparatus for simultaneously supplying varying proportions of hot and cold direct reduced iron(DRI) material from a source of hot DRI for melting, storage, briquetting, or transport. The system uses gravity to transport hot DRI material from a reduction furnace to a furnace discharge section, which transports desired amounts to a cooling receptacle and to a hot DRI vessel. The cooling section of the apparatus is connected to the furnace discharge section through a dynamic seal leg. The hot section is also connected to the furnace discharge section through separate a dynamic sealing leg and can feed a surge vessel, a briquetter, a storage vessel or a melting furnace. The method of operation is also disclosed.
| 8
|
FIELD OF THE INVENTION
The invention relates to a system and method providing a multi-subshelf communication system for a network element of a communication network.
BACKGROUND OF INVENTION
Many communication switch and router systems architecture enable a service to be selected from a plurality of sources located on multiple shelves. Frequently master-slave arrangements may be used where a master controller provides resources to, or is accessed by, one of a plurality of slave devices. However, prior art systems lack a mechanism to provide a guaranteed bandwidth of access for each slave device to the master unit where there is significant amount of communication sent between the two entities in the switch. As such, in communication systems, for example, prior art master-slave systems, cannot provide maximum latency guarantees for transmissions therethrough. There is a farther need for a system which provides maximum latency guarantees where there are multiple shelves therein.
There is a need for a system and method providing minimum bandwidth access for multi-shelf systems that improves upon prior art systems.
SUMMARY OF INVENTION
In a first aspect, a multi-shelf communication system for a communication switch having comprising a plurality of shelves is provided. The communication system comprises a master controller generating commands and receiving status signals, slaves associated with the master controller, a communication controller for each slave, a downstream communication link comprising a multiplexed signal gathering communications from each communication controller into a single multiplexed stream and providing a demultiplexed signal split from the single multiplexed stream to each slave, an upstream communication link from each slave to its communication controller, and a timing arrangement controlling transmission times of communications carried on the downstream communication link. Each slave can be located on one the shelves and receives commands, executes local commands responsive to the commands and generates status signals for the master controller. Each communication controller receives commands, transmits the commands to its slave, receives status signals and provides information relating to the status signals to the master controller. The local commands executed by the slaves replace other commands directed by the master controller to the slave. Each slave communicates independently with the master controller.
The system may have the timing arrangement utilizing a time division multiplex scheme.
The system may have the upstream communication link comprising a multiplexed signal gathering communications from each the slave device into a second single multiplexed stream and providing a second demultiplexed signal split from the second single multiplexed stream to each communication controller.
The system may have the master controller associated with a control card for the communication switch.
The system may have at least one slave as a fabric interface card.
The system may have at least one slave as a line card.
The system may synchronize communications carried in the downstream communication link and the upstream communication link.
In other aspects of the invention, various combinations and subset of the above aspects are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects of the invention will become more apparent from the following description of specific embodiments thereof and the accompanying drawings which illustrate, by way of example only, the principles of the invention. In the drawings, where like elements feature like reference numerals (and wherein individual elements bear unique alphabetical suffixes):
FIG. 1 is a block diagram of elements of a switch of an embodiment of the invention;
FIG. 2 is a block diagram of components and connections of the switch of FIG. 1 ;
FIG. 3 is a block diagram of midplane connection of the switch of FIG. 1 ;
FIG. 4A is a block diagram of a controller unit and shelf units of a further embodiment of the switch of FIG. 1 ;
FIG. 4B is a block diagram of a controller unit and shelf units of a further embodiment the switch of FIG. 1 ;
FIG. 5 is a block diagram of a cabling and interface arrangement for the controller and shelf units of the switch of FIG. 4B ;
FIG. 6 is a timing diagram of time slots for the communication protocol used between the controller and shelf units of the switch of FIG. 4B ; and
FIG. 7 is a block diagram of multiplexing system for ingress transmissions associated with the switch of FIG. 4B .
DETAILED DESCRIPTION OF THE EMBODIMENTS
The description which follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not limitation, of those principles and of the invention. In the description which follows, like parts are marked throughout the specification and the drawings with the same respective reference numerals.
Basic Features of System
The following is a description of a system associated with the embodiment. Briefly, the system provides a multi-shelf communication arrangement of devices in a communication switch. The arrangement is a master-slave system where a controller is provided as the master controller and a plurality of devices are the slave devices.
Referring to FIG. 1 , switch 100 is a multi-protocol backbone system, which can process both of ATM cells IP traffic through its same switching fabric for customer premise equipment (CPE) 102 connected thereto. Through a plurality of cards and processing modules, switch 100 provides CPEs 102 with access to its switching fabric 104 which is the core of switch 100 . The switching fabric 104 provides a matrix allowing each CPE 102 to be connected to other devices connected to the switch 100 . In the present embodiment, switch 100 allows scaling of the switching fabric capacity from 50 Gbps to 450 Gbps in increments of 14.4 Gbps by the insertion of additional shelves into the switch 100 .
CPEs 102 are connected to switch 100 via optical links 106 to I/O cards 108 . I/O cards 108 provide the main input and output interface for conversion of communications between CPEs 102 and switch 100 . I/O cards 108 provide minimal intelligent processing of communications passed therethrough. I/O cards 108 are connected to line cards 110 via midplane connections 112 . Each line card 110 provides OC-192 functionality, bandwidth provisioning and ATM processing of cells between core of switch 100 and each CPE 102 . Each line card is also connected to a fabric interface card (FIC) 114 , which converts the signal to an optical signal and provides an interface for the communications with core 104 .
Accordingly the FIC can monitor and react to conditions reported by the line card 110 . For example, the FIC 114 may analyze and respond to failures reported by its line card 110 , conduct sanity checks on data received from its line card 110 and send reporting messages to upstream shelf controller (described later).
FICs 114 communicate with LPC 110 via midplane connections 116 and with core 104 via connections 118 . The interface to core 104 for each FIC 114 is a switch access card (SAC) 120 .
For improved reliability switch 100 is designed as a redundant source system. Accordingly, each I/O card 108 , line card 110 and FIC 114 has a redundant counterpart, which is noted with the ‘b’ suffix. Accordingly, midplane connections 112 and 116 provide cross connections between the redundant and primary devices. For example, I/O cards 108 and 108 b are connected to line cards 110 and 110 b and line cards 110 and 110 b are connected to FICs 114 and 114 b.
To provide modular physical grouping of components, I/O card 108 , line card 110 and FIC card 114 are grouped together in a single high speed peripheral shelf (HSPS) 122 . Each HSPS 122 has two sets of I/O card groupings in slots 126 to provide redundancy between the groups of shelves. Switch 100 enables the use of multiple HSPSs 122 to provide enhanced expandability for the switch. Accordingly, with components grouped into shelves, a number of individual shelves can populate a switch 100 to provide modular functionality for switch 100 . However, the use of a modular system requires that control signals for each shelf are also provided in modules, as necessary. This entails separate cabling of bundled control signals to each shelf at a communications point on each shelf. From the communication point, individual signals for individual components in the shelf are isolated and forwarded accordingly.
Each I/O card 108 grouping in HSPS 122 must be controlled and coordinated with the other I/O cards 108 in HSPS 122 . Accordingly the embodiment provides a shelf controller 124 which controls operating aspects of shelves 122 connected to it. Such control operations include managing control and status functions for the shelf (such as slot monitoring and fan unit control), controlling FIC configuration for each line card 108 , power rail monitoring and clock signal monitoring.
Shelf controller 124 provides control connectivity via a specialized control service link (not shown). Data carried in the control service link controls downstream configuration and software downloading, time stamping, and synchronization of clocks.
A terminal 128 is connected to switch 100 and runs controlling software which allows an operator to modify, and control the operation of, switch 100 .
Referring to FIG. 2 , switch 100 physically comprises a chassis 200 , which houses HSPS 122 in cavity 202 . HSPS 122 is contained in housing 204 , which sits in a section of cavity 202 . Shelf controller 124 is located above cavity 202 . Each housing 204 contains a midplane 206 , which is a physical support structure having connectors allowing line cards 110 , FICs 114 and I/O cards 108 to be connected thereto. Connections 112 and 116 (see, FIG. 1 ) are provided by appropriate electrical connections between connectors in midplane 206 .
Referring to FIG. 3 , view 300 illustrates line card 110 , I/O card 104 , and FIC card 108 and midplane 206 for housing 204 . Cards that have optical interfaces, namely the I/O card 104 and FIC card 108 , are located on one side of the midplane 206 and line card 110 is located on the other side of the midplane 206 . Connectors 208 provide the physical interface for the cards to midplane 206 . Specific connections between I/O card 104 and line card 110 and FIC card 108 are provided from the pins of various connectors 208 through midplane 206 .
It will be appreciated that terms such as “routing switch”, “communication switch”, “communication device”, “switch”, “network element” and other terms known in the art may be used to describe switch 100 . Further, while the embodiment is described for switch 100 , it will be appreciated that the system and method described herein may be adapted to any switching system.
Referring to FIG. 1 , with a large number of I/O cards 108 , there is a need to have a mechanism for providing instructions from the shelf controller 124 to each line card 110 . Traditionally, either the remote line card was dumb, having no processing capabilities, e.g. a typical I/O card, or alternatively, all of the intelligence was placed on the line card, e.g. a typical line card or a FIC. However, by migrating the intelligence of the processing from either fully on the card or fully off the card, the computing power required at the processing end becomes too large for the processing entity.
Accordingly, the embodiment utilizes a system wherein computing is distributed between the FIC 114 and the shelf controller 124 . At a broad level, the shelf controller 124 identifies what actions need to be taken by a FIC 114 and sends an appropriate instruction to the FIC 114 . Each FIC 114 receives and processes its instruction and provides a suitable response to the shelf controller 124 . In this view, the “master” element is the operative element in the shelf controller 124 and the “slave” element is the FIC 114 . The term “master” is used interchangeably with “shelf controller” and the terms “slave” and “FIC” are also interchangeable for this specification. It will be appreciated that in other embodiments, the slave may be line card 110 or any other downstream device to the master.
Referring to FIGS. 4A , 4 B and 5 , the embodiment provides an egress communication system 400 for each HSPS 122 and the shelf controller 124 . In the shelf controller 124 master controller 402 produces individual commands for each FIC 114 in each subshelf 122 . Communication controllers 404 in shelf controller 124 receive each command for each FIC, or slave 114 and has them sent to each slave 114 . Each HDLC communication controller 404 communicates with the FIC cards in slave 114 to request read/write access to FIC registers (not shown). For example, on a “read” command, master controller 402 may require status data about slave device 114 a . In the distributed system, master controller 402 generates a read command for a particular flag of slave device 114 a . Communication controller 404 a receives the command from master controller 402 and has the command sent, ultimately, to slave device 114 a , which receives the read command and processes it. After the read command is processed by slave device 114 a , a response is generated and is sent back to master controller 402 through an ingress communication system 500 , which provides an ingress communication link from each slave device 114 a to controller 404 a.
Each controller 402 uses HDLC (High Level Data Link Control) protocol. HDLC is a known ISO and ITU-T standaridized link layer protocol used in point-to-point and multi-point communications. HDLC provides bit-oriented synchronous transmission of variable length frames. In the embodiment, master 124 has unbalanced links with slaves 114 . Accordingly, master 124 polls each slave 114 as necessary, and each polled slave 124 responds with information frames. The master 124 then acknowledges receipt of the frames from the slave. It will be appreciated that other communication protocols may be used. It will be appreciated that as there is a dedicated master for each slave, collectively, polling amongst all slaves can be done concurrently.
Shown below is an HDLC frame used in the embodiment by the egress system of FIG. 4A .
Start HDLC End Flag Cntrl Data Field CRC Flag 8 8 X 16 8 bits
The field length (in bits) is variable, depending on the HDLC control field. As an example, master 404 may request to a slave 114 to respond with a report of the status of all interrupts on slave card 114 . Accordingly, the slave 114 would read all its registers that contain an interrupt status. An interrupt status may, for example, store the change of state information of an optical signal received by a pin diode. The slave 114 collects the register information and transmits it to master 402 per the designed communication protocol. It will be appreciated that this distributed messaging system overall provides a faster response time than have a master communicate with each slave device individually to and read their register status. Further, as each slave 114 only has knowledge of its local status, the master can collect all slave 114 information, then provide a response based on the net status of all slave registers. Referring to the earlier example of a read cycle, in the embodiment when master controller 402 requires data from a particular slave 114 a , the control field is set to 00000000 by software in master controller 402 and the data field is defined as 32 bits containing an embedded 16 bit slave address as shown below:
Data field Structure
Read/
Address
Data
Write
Bus
Bus
1
15
16
Referring to FIG. 4A , in one embodiment, it will be appreciated that for the master-slave system, it is possible to have a communication system where each communication controller 404 is individually hardwired to each slave 114 with links 405 . In another embodiment, in order to reduce the number of physical communication links between the communication controllers 402 and the slaves 114 , multiplexing of signalling links is provided on both the ingress and egress directions. This is shown in FIG. 4B .
Accordingly, referring to FIGS. 4B and 5 , for multiplexing signals, each communications controller 404 receives instructions from master controller 402 ; each HDLC controller 404 is connected to multiplexer 406 , producing one serial stream of data containing N channels of data on serial link 408 .
Each communication controller 404 and master controller 402 is contained within a microprocessor 420 . In the embodiment, microprocessor 420 is a MPC 8260 Power PC PowerQUICC II programmable processor, available from Motorola, Inc. Microprocessor 420 has a programmable multichannel controller (MCC). The embodiment configures the MCC to provide the 16 communication controllers 404 . Microprocessor 420 also has an internal multiplexer 406 to produce single datastream 408 from the datastreams produced by the communication controllers 404 . Also, microprocessor 420 has a time slot assignor 421 which assigns a 8-bit timeslot from the TDM stream 408 to each of the controllers 404 . The stream contains sixteen 8 bit slots operating at 8.25 MHz. Accordingly, the TDM stream in link 408 comprises 16 serial packets as shown below:
Ch 0 Ch 1 Ch 16 HDLC 1 HDLC 2 . . . HDLC 16
It is desirable to have the HDLC timeslot at a minimum length (and thus the TDM stream at a minimum length) to decrease the latency on time-sensitive information in the TDM stream (such as interrupt status).
Serial link 408 is provided to a group demultiplexer 410 which collectively groups the N channels into M channels 412 . The demultiplexer 410 is embodied in a field programmable gate array (FPGA) 410 .
Control for demultiplexer 410 is fixed and the demultiplexing does not change on different conditions. As will be further described later, a bit counter signal and a channel counter signal are associated with the TDM stream. The bit counter signal and the channel counter signal are used by demultiplexer 410 to identify which bits from controllers 404 (or which bits from registers within FPGA 410 ) are inserted into which channel 412 at the correct frame.
The FPGA 410 provides the following functions for microprocessor 406 . First, the TDM stream 408 between the microprocessor 420 and FPGA 410 contains HDLC interfaces for FIC communications. The FPGA splits out TDM stream 408 into individual M TDM streams 412 for each of the HSPS sub-shelves 122 . Control signals are embedded into the TDM stream 408 by FPGA 410 . Second, control signals for a FIC, such as Line Card Presence, sub-shelf Number, FIC Interrupt Status, etc. may be transmitted between microprocessor 420 and slave 110 using the signal multiplexing scheme and FPGA 410 . Microprocessor 420 provides a request for control signals for a FIC to FPGA 410 sent via 60× bus 422 . FPGA 410 inserts an appropriate request in the appropriate timeslot for the requested slave 114 in the appropriate egress datastream 412 . The targetted slave responds to the request and transmits the status to FPGA 410 via the ingress multiplexed stream. The results are stored in FPGA registers, which can be accessed by microprocessor 420 over bus 422 . Also, FPGA 420 may send a (maskable) interrupt to microprocessor 420 upon a status change of a control signal. Third, FPGA 410 also performs a digital phase comparisons of the selected sources of timing from the shelf 124 and compares it with the system source sent to the shelf.
From the FPGA 410 , four TDM streams 412 connect the shelf controller to each of the four subshelves. In the embodiment, the second TDM stream is a 16 timeslot frame operating at 8.25 MHz for each subshelf 122 . Each M channel 412 is provided to each subself 122 . Each of the four TDM substreams 412 (one to each sub-shelf) is a 16 timeslot frame operating at 8.25 MHz.
Similar to demultiplexer 410 , TDM demultiplexer 414 utilizes the bit counter signal and the channel counter signal to determine which incoming part of the datastream on channel 412 is sent on which outgoing channel 416 .
In each subshelf 122 , demultiplexer 414 receives each channel 412 and produces N/M separate communication links 416 , each of which is provided to each slave 114 . Each slave device 114 has a HDLC interface module 418 which translates the HDLC encoded datastream 416 into a format which can be used by each slave 114 . Each communication controller 404 has a timeslot in the TDM stream assigned to it. Similarly, each slave device 114 has a timeslot assigned to it for sending information to the master controller. Also, slave devices 114 can interrupt the master controller 124 at any time, if required.
Having a dedicated communications controller 124 and corresponding control bandwidth for each slave device 114 ensures that control commands from the master controller 402 will be received by the slave devices 114 within a deterministic amount of time.
Referring to FIG. 7 , for multiplexing signals in the ingress direction, system 700 is shown. Therein, each slave 114 generates a response or a signal destined for master controller 402 ; each slave 114 is to multiplexer 702 , producing one serial stream of data containing N/M channels of data on serial link 704 .
Serial link 704 is provided to FPGA 410 which processes the information in the N/M channels 704 and provides an appropriate response, if necessary to master controller 402 via 60×bus 422 .
Since each slave device 114 has its own timeslot during which it can communicate with the controller 402 , information from the slave devices 110 will reach the master controller 402 within a defined amount of time. This allows bidirectional communications between the slave devices and the master controller to occur within a guaranteed latency. Accordingly, the embodiment allows a multishelf platform to detect a fault within 10 ms re-route around the fault within 50 ms, thereby conforming with requirements of a carrier-grade system.
It will be appreciated that ingress multiplexing system 700 shares functional similarities with egress system 400 . However, in addition, line cards 110 and I/O cards 108 generate some status signals as dc signals (not shown) which are provided to their CPLD 702 . Each CPLD may embed these signals into the datastreams of its respective channel 704 . At FPGA 706 , these embedded signals may be extracted and processed locally as needed. For example, they may be provided to other cards and systems associated with the FPGA 706 .
In the embodiment, an ingress signalling system is also provided, which is similar to egress system 400 , and is described later.
Referring to FIG. 6 , each TDM bus is configured according to the following timing parameters. Each multiplexer has access to these timing signals. A common clock 602 operates at 8.25 MHz and a frame pulse (FP) 604 operates at 64.45 KHz. The rising edge of FP 604 is aligned to the rising edge of clock 602 . The FP defines a frame for a byte of transmitted information.
Within each frame pulse, there are 16 timeslots, one slot for each slave device. The current timeslot number in the TDM stream is indicated by timeslot signal 608 . In order to provide the system with an earlier indication of the arrival of the next timeslot, timeslot count signal 608 in generated which is the same count signal as timeslot signal 606 , but it is generated half a clock cycle earlier.
Within each timeslot there are eight bit positions. The current bit position is indicated by bit position signal 610 . As with the timeslot signal 606 , as a mate to bit position signal 610 , bit position count signal 612 is generated to provide the system with an earlier indication of the arrival of the next bit position.
These signals are generated by the FPGA 410 (not shown). The first bit of the first timeslot (bit 7 of timeslot 0 ) is the MSB and will be coincident with the rising edge of FP 406 . As there are 8 bits of data per timeslot, for data transactions involving data fields of more than 8 bits requires more than 1 TDM slot. Successive required slots are provided in the next TDM superframe.
Also, the timing of signals sent between shelf controller 124 to each of subshelf 104 requires that no cells be dropped. Timing is handled in the following manner.
Referring to FIG. 4 , for each controller 404 , each HDLC stream is transmitted at a clocking rate of 8.25 MHz/16, i.e. approximately 516 kHz (or “R” for “Rate”), to multiplexer 406 . Once all of the 16 TDM streams are combined into a single TDM stream at multiplexer 406 , the collective datastream is clocked at 16×R on serial link 408 to ensure that successive packets from each controller 404 in successive frames are not lost. The collective datastream on link 408 is provided to FPGA 410 which splits datastream into four separate datastreams on channels 412 . Each separate datastream on each channel 412 contains datastreams for 4 HDLC slots destined for demultiplexers 414 associated with each subshelf 122 . The clocking rate for each datastream on each channel 412 is still. 16R. Accordingly, there is additional bandwidth available in each datastream in each channel 412 , as only four slots are needed in the time frame which contains 16 time slots. Accordingly, 12 control slots are added to each datastream in each channel 412 by FPGA 410 . The control slots contain information embedded into them by FPGA 410 .
From each demultiplexer 414 , each datastream is then passed to a CPLD within demultiplexer 414 , which can extract some of the control information from the datastream for the FIC 114 or line card 110 . The CPLD is located on midplane 206 . The CPLD 414 further splits the datastream into four sub datastreams on channels 416 , 1 channel 416 per slave device 114 . At each slave device 114 , a second CPLD (#2) can extract further control information from the received datastream. The received HDLC datastream is then clocked-down to the original clocking rate of 8.2 MHz/16, i.e. approximately 516 kHz (R). The clocked-down data for data transmissions received by a slave device 114 contains the original information embedded in the TDM stream from its corresponding controller 404 a.
It will be appreciated that in the above timing arrangement, timing is maintained for the data rate and additional control information is provided in each datastream without occupying “true” bandwidth from the master-slave communication link.
Following is an example of latency aspects of the system. In the embodiment there are 16 timeslots in the TDM stream 408 , which is clocked at 8.25 MHz. Accordingly it takes 15.5 us to transmit the whole TDM stream 408 . An average read or write cycle for microprocessor 420 on the FIC is 200 ns (4-clock cycle access at 20 MHz). When the FIC microprocessor gets a local interrupt it performs 11 reads (in the worst case) to determine the source (1 interrupt cause register, then 10 registers). Accordingly the processing time is:
11×200 ns=2.2 us
The microprocessor must also write the contents of these 10 registers into the HDLC FIFOs, thereby requiring
10×200 ns=2 us
For a worst-case scenario of a 120-bit HDLC frame, there are 120 bits required for the HDLC frame (see frame below) and there are 8 bits of the HDLC frame transmitted each TDM stream, it takes 15 TDM streams to transport this HDLC frame back to the microprocessor 420 , i.e. 15×15.5 us=232.5 us.
If a factor for receiver latency of 2 TDM frames is
2×15.5=31 us,
it takes 2.2+2+232.5+31=267.7 us.
As noted earlier, each HDLC link is dedicated, so if all 16 FIC 114 were reporting to their respective masters 404 , the total maximum service time is still 267.7 us.
It is noted that those skilled in the art will appreciate that various modifications of detail may be made to the present embodiment, all of which would come within the scope of the invention.
|
A multi-shelf communication system for a communication switch having shelves is provided. There is a master generating commands and receiving status signals, slaves associated with the master, a communication controller per slave, a downstream communication link providing a multiplexed signal of communications from each controller and providing a demultiplexed signal split from the multiplexed signal to each slave, an upstream communication link from each slave to its controller, and a timing arrangement controlling transmission times for the downstream communication link. Each slave can be located on one the shelves and receives commands, executes local commands responsive to the commands and generates status signals for the master. Each controller receives commands, transmits commands to its slave and receives status signals and provides information relating to the status signals to the master controller. Local commands replace other commands directed by the master to the slave. Each slave communicates independently with the master.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to an optical fiber socket, and more particularly to such a socket with an integral switch.
2. Description of Related Art
With continuing advances in information technology, more than one medium input socket may be required. That is, an optical fiber input in addition to an auxiliary socket such as an A/V input is now necessary for many workstations. Conventional workstations may have two or more inputs, and a user has to manually operate a separate switch to turn on or off the desired input. The separate switch inevitably results in a high cost, complicated assembly, loss of space, high chance of failure, and general inconvenience.
As shown in FIG. 5, a conventional fiber socket ( 50 ) for receiving signals via an optical fiber cable plug ( 60 ) includes a recess ( 51 ) configured to receive a tip ( 61 ) of the plug ( 60 ). The recess ( 51 ) has a flap ( 59 ) which is pivoted into a housing by a hinge ( 590 ). The flap ( 59 ) provides a seal against foreign matter which would otherwise impair the quality of fit of the plug ( 60 ) in the socket ( 50 ) and subsequently impair the quality of the received signals delivered by the cable. Such a socket has the aforementioned drawback of requiring an additional switch by which a user can actuate this socket.
Additionally, the tip ( 61 ) of the optical fiber plug ( 60 ) is often damaged as it brushes against the flap ( 59 ) when the plug ( 60 ) is being inserted in the recess ( 51 ), whereby signals travelling along the cable may not be transmitted efficiently between the plug and the socket.
Furthermore, the recess ( 51 ) has a configuration such that the plug ( 60 ) can only be received therein in one position. That is, the plug ( 60 ) has two ridges ( 63 ) extending from opposed side faces thereof, and another side face with two beveled corners. The recess ( 51 ) of the socket ( 50 ) is configured to matingly receive the plug ( 60 ) and so the ridges ( 63 ) and beveled corners limit the alignment between plug ( 60 ) and socket ( 50 ) to one position only. Such a positional limitation is not only inconvenient for a user trying to insert the plug ( 60 ) in the socket ( 50 ), which is often in poorly-accessible situation, it also may lead to excessive stress on the cable due to twisting of the optical fiber cable.
Therefore, it is an objective of the invention to provide an optical fiber socket with an integral switch to mitigate and/or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
The main objective of the present invention is to provide an optical fiber socket with an integral switch.
An optical fiber socket in accordance with the present invention includes a housing with a flap at one end covering a recess to receive an optical fiber plug, and a cartridge mounted to a bottom of the housing. The cartridge receives therein a switch device which is moved between an isolated status and a conductive status by a user raising or lowering the flap of the housing, whereby the socket is automatically actuated or isolated.
More specifically, an optical fiber socket containing an integral switch to select between an electrically isolated mode and an actuated mode includes a housing having a recess configured to receive therein an optical fiber plug and defined at one end thereof, a flange extending along three sides of the one end, a flap pivotally attached thereto and receivable in an area defined by the flange, an under face, and at least one passage extending between the area defined by the flange and the under face.
The socket further includes a cartridge having a top face configured to mate with the under face of the housing and retained with the housing by a clip, and a switch device received between the top face of the cartridge and the under face of the housing and partly extendable through the at least one passage of the housing to protrude into the area defined by the flange when the socket is in the actuated mode with the flap raised away from the flange. When the flap is received within the flange the switch device is urged back by the flap from the area defined by the flange when the socket is in the electrically isolated mode.
In further developments, the switch device advantageously includes a first electrical conductor, a second electrical conductor, and an isolator sandwiched between the first and second conductors and movable between a first position to achieve the isolated mode wherein the first and second conductors are electrically isolated from each other, and a second position to achieve the actuated mode wherein the first and second conductors are in electrical contact with each other and complete a circuit between an optical fiber plug received in the recess and the outgoing connections.
The first electrical conductor advantageously includes a top portion shaped as a U and including two side bars and a middle bar integrally extending between the side bars, and a bottom portion extending downward from the middle bar of the top portion, the middle bar further including a raised central section from which the bottom portion extends. The second electrical conductor is substantially shaped as an F and includes an upright bar with a cross bar formed at a top end thereof, two downwardly-inclined resilient fingers formed on the upright bar and extending in a direction opposite the direction of the cross bar, each of the fingers having a distal tip formed horizontal to a respective one of the inclined parts, and each distal tip of the fingers having an upwardly-inclined tab extending in a direction of the upright bar. Furthermore, the isolator is shaped substantially as a U and is movably retained between the first and electrical conductors, and includes two opposed side strips each with a first end and a second end, and a central strip integrally extending between the two side strips and near the first ends thereof, each first end having a beveled front face configured to mate with a respective one of the tabs of the second electrical conductor. In the isolated mode the second ends of the isolator extend respectively through two of the passages of the housing to abut an inner face of the flap, and the tabs of the second electrical conductor and the side bars of the first electrical conductor are separated from each other by the beveled front faces of the isolator urging against the tabs of the second electrical conductor, and in the actuated mode the second ends of the isolator extend respectively through and protrude from the passages of the housing, the tabs of the second electrical conductor contact the side bars of the first electrical conductor and complete a circuit between an optical fiber plug received in the recess and the outgoing connections.
The flap advantageously includes two opposed stubs respectively engageable with two orifices defined in opposed sides of the flange, when the socket is in the isolated mode.
The flap may also advantageously include a window element, and the window element advantageously is tinted to reduce intensity of light passing therethrough. In a further development, a surface of the window element is contoured to reduce intensity of light passing therethrough.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of an optical fiber socket with an integral switch in accordance with the present invention;
FIG. 2 is a side elevation, partly in cross-section, of the socket shown in FIG. 1;
FIG. 3 is a cross-sectional side elevation of the socket shown in FIG. 1, in an isolated mode;
FIG. 4 is a cross-sectional side elevation of the socket shown in FIG. 1, in an actuated mode; and
FIG. 5 is a perspective view of a prior art socket for receiving an optical fiber plug.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the figures and particularly FIG. 1, an optical fiber socket ( 10 ) includes a housing ( 11 ), a cartridge ( 12 ) mounted to an under face of the housing ( 11 ) by a clip ( 16 ) extending therearound, and an electrically-conductive device received between the mated housing ( 11 ) and cartridge ( 12 ).
Referring to FIG. 1, the housing ( 11 ) comprises a recess ( 110 ) defined in a first end face thereof, and a U-shaped flange ( 111 ) extending from a bottom edge and two side edges of the first end face, whereby a space is defined at a top edge of the first end face. The flange ( 111 ) has two identical side walls joined at their bottoms by a bottom wall. Each side wall of the flange ( 111 ) has a pivot hole (not numbered) defined therein near a top point thereof, and an orifice ( 112 ) defined therethrough and below the respective pivot hole. Two passages ( 113 ) extend from the bottom edge of the first end face and below the recess ( 110 ) to exit at the under face of the housing ( 11 ). The recess ( 110 ) has four substantially straight sides each with a longitudinal notch ( 114 ) defined at a central point thereof and sized to receive a corresponding ridge of an optical fiber cable (not shown), whereby the cable can be fitted in the recess ( 110 ) in four different positions each 90 degrees in rotation from the subsequent position. A flap ( 20 ) is configured to be received within the flange ( 111 ) and includes two side edges each with a dowel formed at a top thereof and which are sized to be pivotally received in a respective one of the pivot holes, and a stub ( 22 ) sized to be receivable in a respective one of the orifices ( 112 ). The side walls of the flange ( 111 ) have a degree of resiliency which enables them deform sufficiently to retainedly receive and release the stubs ( 22 ). The flap ( 20 ) further includes a bar ( 24 ) protruding from a front face thereof, whereby a user can pull the flap ( 20 ) upward and away from the flange ( 111 ) to access the recess ( 110 ). Additionally, the flap ( 20 ) may also include a window portion ( 26 ), in this embodiment a circular portion is shown though it is to be appreciated that any configuration is practical, to allow light to pass therethrough into the recess ( 110 ). Because light can travel in two directions through the socket ( 10 ), a user may wish to look into the socket via the window portion ( 26 ) to determine whether light is outgoing from the socket ( 10 ). In order to protect a user's eyesight, the window portion may be tinted to reduce intensity of the light. The window portion may further have a surface with a special contour to reduce the intensity of light viewable therethrough, instead of the tint.
Still referring to FIG. 1, the cartridge ( 12 ) is substantially L-shaped and has an upper periphery configured to mate with the under face of the housing ( 11 ). The cartridge ( 12 ) includes a high end wall at a rear end thereof, a front block ( 120 ) at a front end thereof, a cavity extending substantially between the end wall and the front block ( 120 ), and a central block ( 121 ) protruding from a top face defining the cavity. The front block ( 120 ) has a notch defined in a top face thereof. A front slot ( 124 ) defined close to front block ( 120 ) communicates the cavity with an under face of the cartridge ( 12 ). A rear slot ( 126 ) defined between the central and front blocks ( 121 , 120 ) communicates the cavity with the under face of the cartridge ( 12 ).
Again referring to the figures and FIG. 1 in particular, the electrically conductive device comprises an isolator ( 13 ) made of a non-conductive material, a first electrical conductor ( 14 ), and a second electrical conductor ( 15 ). The isolator ( 13 ) is substantially U-shaped and includes two opposed side strips ( 131 ) each with an inner edge and an outer edge, and a central strip ( 130 ). The side strips ( 131 ) are joined at first ends thereof by the central strip ( 130 ) extending between the inner edges. First ends of the side strips ( 131 ) also include a beveled front face ( 133 ). The first conductor ( 14 ) comprises a top portion ( 140 ) shaped as a U when viewed from above, and a bottom portion ( 142 ) extending downward from a middle bar of the top portion ( 140 ). The middle bar of the top portion ( 140 ) further includes a raised central section from which the bottom portion ( 142 ) integrally extends. Two side bars ( 144 ) extend in a same direction from respective ends of the middle bar of the top portion ( 140 ). The second conductor ( 15 ) is substantially F-shaped when viewed from the side, and comprises an upright bar ( 151 ) with a cross bar formed at a top end thereof, two downwardly-inclined resilient fingers ( 152 ) extending from opposed edges of a distal tip of the cross bar, and two resilient arms ( 154 ) extending in a direction opposite that of the cross bar, and formed on the upright bar ( 151 ). Each finger ( 152 ) has a distal tip ( 150 ) formed horizontal to a respective inclined part, and each distal tip ( 150 ) has an upwardly-inclined tab ( 1500 ) extending in the direction of the upright bar ( 151 ). The tabs ( 1500 ) are configured to respectively mate with the beveled front faces ( 133 ) of the isolator ( 13 ).
In assembly, referring to FIG. 2, a lower tip of the upright bar ( 151 ) of the second conductor ( 15 ) is received in the rear slot ( 126 ) of the cartridge ( 12 ) such that the arms ( 154 ) of the second conductor ( 15 ) are in the cavity, the cross bar rests on the central block ( 121 ), and the fingers ( 152 ) extend down towards the face defining the cavity. The bottom portion ( 142 ) of the first conductor ( 14 ) is received in the front slot ( 124 ) of the cartridge ( 12 ) such that the two side bars ( 144 ) of the first conductor ( 14 ) extend into the cavity. The isolator ( 13 ) is mounted over the first conductor ( 14 ) and below the second conductor ( 15 ) such that the beveled front faces ( 133 ) of the isolator ( 13 ) can separate the tabs ( 1500 ) of the second conductor ( 15 ) from being in contact with the side bars ( 144 ) of the first conductor ( 14 ). The side strips ( 131 ) of the isolator ( 13 ) respectively extend into the passages ( 113 ) of the housing ( 11 ) such that the second ends of the side strips ( 131 ) can protrude from the front face of the housing ( 11 ) combined with the cartridge ( 12 ). In the isolated mode shown in FIG. 3, the flap ( 20 ) is closed and held in place by the stubs ( 22 ) respectively engaging with the orifices ( 112 ), and the isolator ( 13 ) is pushed forward by the flap ( 20 ) urging against the second ends of the isolator ( 13 ). Accordingly, as the isolator ( 13 ) is moved forward, the central strip ( 130 ) thereof urges against the arms ( 154 ) of the second conductor ( 15 ) to put them in tension, and the beveled front faces ( 133 ) separate the tabs ( 1500 ) of the second conductor ( 15 ) from being in contact with the side bars ( 144 ) of the first conductor ( 14 ). Referring to FIG. 4 which shows the socket ( 10 ) with the flap ( 20 ) raised and in the actuated mode, the isolator ( 13 ) is free to move backward under force from the stored tension in the arms ( 154 ) of the second conductor ( 15 ), such that the tabs ( 1500 ) move downward to contact the side bars ( 144 ) of the first conductor ( 14 ). Further connection within the socket ( 10 ) to an appliance is conventional and thus not described in further detail.
This is shown in FIG. 4, wherein an appliance ( 30 ) is connected with the socket ( 20 ) in the actuated mode.
The socket of the present invention has the following advantages:
1. The flap has double function in that it keeps out foreign matter which might otherwise impair incoming signals, and replaces the additional switch necessary in prior art to actuate/isolate the optical fiber mode;
2. The flap has a window to enable safe determination of whether light is present in the socket; and
3. The socket can receive an optical fiber plug in any one of four positions.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
|
An optical fiber socket with an integral switch includes a housing, a cartridge fitted to an under face of the housing, and a switch device sandwiched between the housing and the cartridge. The housing includes a recess which can receive an optical fiber plug therein when a flap covering the recess is raised. Raising and lowering of the flap actuates or isolates the switch of the socket.
| 8
|
FIELD OF THE INVENTION
This invention relates to the field of amusement devices. Specifically this invention relates to backgammon games.
BACKGROUND OF THE INVENTION
Backgammon, a board game, has traditionally been played by two persons. The backgammon playing board used for this ancient game is arranged with 24 positions or playing points over which the players alternately move their respective 15 men, pieces or stones according to the roll of dice. The board itself is divided into four quadrents or "tables", with two tables per side and six triangular points per table. The basic object of the game is to be the first player to remove all of his pieces from the table. The pieces of the two players are moved in opposite directions around the board. Initially, each player has eight pieces on his home side or home table and seven pieces on the opposite side or outside table.
The prior art shows attempts to permit backgammon to be played by more than two people at one time. One means of achieving this is known as chouette. In this variation of backgammon, however, not all of the players are of equal status and the game becomes more of a team, not individual, effort.
Other means of achieving play by more than two people are shown in U.S. Pat. No. 4,124,212 granted Nov. 7, 1978; U.S. Pat. No. 4,058,319 granted Nov. 15, 1977; and U.S. Pat. No. 4,058,318 granted Nov. 15, 1977. All of these patents permit the inclusion of more than 2 but not greater than 4 players of equal status. This increase, however, usually required a significant distortion of the traditional and simple backgammon game board. U.S. Pat. No. 4,058,318 allows more than two players by doubling the traditional gameboard size from 24 points to 48 points.
U.S. Pat. No. 4,085,319 permits more than two players by increasing board size from 24 up to 60 playing points and by completely rearranging the layout of the backgammon quadrents or tables.
U.S. Pat. No. 4,124,212 also increases the playing points from 24 to 45 so as to allow for more than two players. This prior art also significantly rearranges the layout of the backgammon gameboard quadrents or tables, and further, redesigned the traditionally shaped triangularly shaped playing points into diamond-like designs. These changes, in toto, are so profound as to render this gameboard virtually unrecognizable as a backgammon gameboard and also make it cumbersome in play.
Now there is provided by the present invention a multi-player backgammon game which eliminates the complex and cumbersome play of prior art multi-player games, while retaining the character of the traditional two-player game. This new and unique gameboard allows more than two people to play backgammon within the context of traditional backgammon play without having to acquaint oneself with a confusing table arrangement or contend with an inordinately large and confusing number of pieces on the gameboard.
It is therefore an object of this invention to provide a backgammon game which allows for the simultaneous playing of up to four people and yet which includes the convenience in gameboard layout and ease of understanding of the traditional two player backgammon gameboard.
It is another object of this invention to provide a gameboard for the simultaneous playing of backgammon by up to four people without having any of the four people team-up and wherein all of the players are of equal status and wherein traditional backgammon strategies may be used.
It is a further object of this invention to provide for a backgammon game which will accomodate up to four players with only 40 playing pieces at 10 pieces per player without the confusion and clutter created by the up to 60 playing pieces present in the prior art.
It is another object of this invention to provide a backgammon game which simultaneously accomodates up to four players and, which for ease of identification, both the gameboard and playing pieces are coordinately color coded.
It is still a further object of this invention to provide a backgammon game which when played with a chouette variation, accomodates simultaneously up to 10 players.
The aforesaid as well as other objects and advantages will become apparent from a reading of the following specification, the adjoined claims and the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the backgammon gameboard with pieces arranged for playing four people simultaneously.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 there is shown the plan view of the backgammon gameboard generally identified as 10. The gameboard is bisected widthwise by dividing bar 11. The gameboard is further bisected lengthwise by line border 12 into four quadrents or tables generally indicated as 13, 14, 15 and 16. Said tables each include as first indicia thereon seven playing points and include as second indicia thereon a background area. Further, each of the playing points are one of four colors and correspond with one of the four background areas. Which four specific colors are chosen is purely an arbitrary selection and has no bearing on the claimed invention.
On table 13 the playing points are indicated by 17, 18, 19, 20, 21, 22 and 23 and the background area is indicated by 45. Playing points 17, 18, 19, 20, 21, 22 and 23 color correspond with background area 47 in table 14.
On table 14 the playing points are indicated by 31, 32, 33, 34, 35, 36, 37 and color correspond with background area 45 on table 13. The background area on table 14 is indicated by 47.
On table 15 the playing points are indicated by 24, 25, 26, 27, 28, 29 and 30 and color correspond with the background area 48 on table 16. The background area on table 15 is indicated by 46.
On table 16 the playing points are indicated by 38, 39, 40, 41, 42, 43 and 44 and color correspond with background area 46 on table 15. The background area in table 16 is indicated by 48.
Referring to FIG. 1 there is also shown a typical playing piece, stone or man arrangement in order to accomodate four players. This arrangement is indicated by the variously colored circles on the playing points. In the most preferred embodiment of this invention each player receives ten of these playing pieces. A playing piece may be one of four colors, said four colors preferably being selected from the colors of the gameboard and thereby become color coordinated with said gameboard. The exact color chosen for the playing piece is purely an arbitrary selection and has no bearing on the claimed invention, although whatever color is selected would color correspond with selected playing points and background areas on the gameboard.
When the gameboard is set up to accomodate four players simultaneously, pieces are placed in specific locations as shown in FIG. 1 and described as follows:
Player #1, whose green pieces color correspond with the playing points of table 13, has 3 pieces of playing point 27, 5 pieces on playing point 38 and 2 pieces on playing point 31. Player #2, whose red pieces color correspond with the playing points of table 14, has 2 pieces on playing point 17, 5 pieces on playing point 24 and 3 pieces on playing point 41. Player #3, whose blue pieces color correspond with the playing points of table 16, has 5 pieces on playing point 23, 2 pieces on playing point 30 and 3 pieces on playing point 34. Player #4, whose yellow pieces color correspond with the playing points of table 15, has 3 pieces on playing point 20, 2 pieces on playing point 44 and 5 pieces on playing 37. In order to set up the gameboard so as to accomodate three players simultaneously, the positions of the pieces for players #1, #2 and #3 are the same as when the gameboard is set up to accomodate 4 players and, further, player #4's pieces are left off of the gameboard.
The movement of the play, determined by a random number generating device such as a die or dice, is such that each player moves his men from is primary opponent's inner table to his secondary opponent's inner tables, into his own inner table, and ultimately off the board. Player #1 will, therefore, respectively move his pieces in the direction from table 14 to 16 to 15 to 13. Player #2 will move his pieces in the direction from table 13 to 15 to 16 to 14. Player #3 will move his pieces in the direction from table 15 to 13 to 14 to 16. Player #4 will move his pieces in the direction from table 16 to 14 to 13 to 15.
In terms of actually playing the game, the backgammon procedures and rules set forth below may be applied.
Each player shall roll one die to determine who moves first. The player with the highest number showing on his die gets to determine his own combination using his die and any other player's die (no doubles). Play then rotates counter clockwise, each player using his own die. A player moves his pieces or men around the boards playing points according to the numbers shown on the dice. Cocked dice means that one of the dice has not landed completely flat on the playing board. When this happens the player must throw again. Moves shall be one move for each die or a player can move one man the total sum of the dice as long as the playing points designated by each die are open. Both numbers on each roll must be used when possible. If only one die can be used, it must be the larger of the two if possible. If the player cannot use his move at all, he must pass to his opponent.
"Doublets" mean rolling doubles, i.e., the same number is thrown on both dice. When this occurs a player moves the number shown on one die four times. A player can move the same man all four moves, or any other combinations of men desired.
Once a player lands two or more of his pieces on a playing point he is said to have "made the point". No other player may land on said playing point although they may pass over it. This is a "blocked point". There is no limit to the number of men one player may have on a point.
Any point on which a player has only one piece is a blot. If a player lands on his primary opponent's blot, he removes that piece to the dividing bar 11 and replaces it with his own. This is called a "hit". If player lands on his secondary opponent's blot, the hit piece moves back to the first available playing point (an available playing point is any playing point that is not blocked). This is called a "bump". A bump can result in a hit. If in the event a player's backward movement carries it beyond his point of entry he must then go back to the dividing bar. As an example, if #1 player's piece moves and hits #2 player's piece (primary opponent), #2 player's piece goes on the dividing bar 11. If #1 player's piece hits any other player's piece, but #2's (secondary opponent) then that piece goes back to the first available playing point. When playing with three players, all bumps go back to the dividing bar 11 because all three are primary opponents.
The dividing bar 11 is the middle strip that separates the inner and outer tables and bisects the board widthwise. Once one of a player's pieces has been placed on the bar, he must throw the dice, when his turn occurs, and must "enter" into his primary opponent's inner table before he may move any of his other pieces, Entering is accomplished by moving the piece on the dividing bar 11 to the playing point indicated on either one of the die thrown as long as that point is not blocked. If he cannot enter because both playing points indicated are blocked, the turn passes to his opponent. When all playing points within the primary opponent's inner table are blocked a closed board or shutout occurs.
Bearing Off means removing a player's pieces from the playing board by the roll of the dice. A player cannot start bearing off until all 10 of its pieces are in his inner table. He may then either bear off pieces from points corresponding to die thrown or he may move his pieces within his inner table according to the numbers shown on the dice. He must use his entire roll, if possible. This means that if he rolls a six, but has no piece on his six playing point, he must take off the highest point on which he does have pieces. The same rule applies if he rolls doubles. However, he cannot bear off a man if the playing point indicated on the die is vacant and there are any pieces on a higher counting playing point. If while bearing off, a piece in a player's inner table is "hit" by a primary opponent or bumped into the outer table by a secondary opponent, the player must re-enter the board and/or inner table before he can continuing bearing off.
A doubling cube is used to double the betting stakes. Before the game begins the doubling cube is placed on dividing bar 11 with the number 64 on top and not facing any player. If there is an automatic double the number 2 is placed face up, again not facing any player. If there is second automatic double the number 4 is placed face up, and so on. Automatic doubling occurs on each tie of primary opponents in the opening throw. Voluntary doubling means that a player offers to double the stakes, when it is his turn to play and before he has thrown the dice. A double may be accepted or declined, but the primary opponent declining looses whatever the stakes were before the double was offered. Thereafter, doubling alternates between primary opponents.
A game is won when any one player bears off all of his pieces first. A gammon II (double game) is won if a player's opponents have not born off any of their pieces. A backgammon II (triple game) is won if a player's opponents have not born off any of their pieces and have one or more pieces in their primary opponent's inner table or on the dividing bar 11.
Chouette allows for the inclusion of up to but not more than 10 players in the game. All players roll a die to determine who will be the "men in the box". This honor goes to the players rolling the highest two consecutive or equal numbers, while the players rolling the second highest two consecutive or equal numbers are the captains. In the event of a three or four way tie, among the highest four rolls, all four players roll again. All other players are the captain's partners and rank below the captains according to their roll of the die. The men in the box (primary opponents) and the captains (secondary opponents) play a four-handed game, but the captain's partners give advise for play. If either men in the box looses he then becomes the lowest ranking partner to his new captain. The winning captains become the men in the box. If the man in the box wins then the captain becomes the lowest ranking partner and the previously highest ranking partner becomes that captain.
In the drawings and specification, there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a descriptive sense only and not for purposes of limitation.
Inasmuch as many changes could be made in the above construction, and many apparently different embodiments of the invention could be made without departing from the scope thereof it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
|
A backgammon game is disclosed which accomodates simultaneously two to four players at 10 pieces, men or stones per player, and which gameboard is comprised of four quadrents or tables with seven playing points per table. The 10 pieces in a set are similarly colored, and each set is of a color different from each other set. All the points in a particular quadrant are similarly colored, and the color of the points in each particular quadrant differ from the color in each other quadrant. The color of the points in each quadrant corresponds to the color of the pieces in one of the sets. The backgammon game permits multiple play by four players without a cumbersome board structure and without an unwieldly number of stones per player.
| 0
|
TECHNICAL FIELD
[0001] This invention relates generally to an engine having a predetermined set maximum power rating based on less than ideal site and ambient conditions, and more specifically to controlling the engine to produce a quantity of power in excess of the predetermined set maximum power rating as a function of engine operating conditions.
BACKGROUND
[0002] Many engines are coupled with generators to produce electrical power. These engines are typically configured during manufacture to produce up to a predetermined set power rating. More specifically, an engine controller is normally configured to command the engine to produce up to and no more than the predetermined maximum power rating.
[0003] The predetermined maximum power rating of a particular engine is often calculated using worst case operating conditions for the engine. This is because the amount of power that the engine is capable of producing is usually limited by its operating conditions. For example, if the ambient temperature is very warm, e.g., 43 degrees Celsius, the temperature of the air or air/fuel mixture being sent to the combustion chamber cannot be as cool as a day when a substantially cooler ambient air temperature exists. Within a fairly wide range, the temperature of the air or air/fuel mixture being sent to the combustion chamber has a direct impact on engine power capability.
[0004] The example in the paragraph above generally covers an operating condition where cooler water to the aftercooler (aftercooler water temperature) results in a power increase because the inlet manifold temperature is reduced. Similarly, other engine operating conditions, such as jacket water temperature, inlet manifold pressure, humidity, and whether detonation is occurring during ignition may all affect combustion, and therefore power production.
[0005] Further, many engine controllers limit the power production of an engine to a predetermined set maximum power rating. Thus, even when an engine is operating in better than worst case operating conditions, the engine controller may still use predetermined worst case conditions for calculating the power output. In this instance, the engine typically produces less power than it could, with the additional power producing capabilities of the engine remaining unused.
SUMMARY OF THE INVENTION
[0006] The present invention provides methods and apparatus for controlling an engine having a first maximum power rating based on at least a first predetermined operating condition of the engine. A first sensor transmits a first signal as a function of the engine operating at a predetermined operating condition other than the first predetermined operating condition. A control device receives the first signal and transmits a power signal to the engine as a function of the first signal. The power signal causes the engine to produce a quantity of power in excess of the first maximum power rating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] [0007]FIG. 1 shows a block diagram of an engine system according to one embodiment of the invention.
DETAILED DESCRIPTION
[0008] [0008]FIG. 1 shows a block diagram of an engine system 10 according to one embodiment of the invention. The engine system 10 will be discussed in terms of a natural gas engine, although other types of internal combustion engines, including turbines and diesels could also be used. The engine system 10 typically includes an air delivery system (not shown) that delivers air (e.g., either ambient air or air and some other combustible gas) to an air/fuel mixing device, such as a carburetor 12 or electronic fuel valve. Other types of air/fuel mixing devices known to those skilled in the art could also be used in appropriate embodiments.
[0009] A fuel delivery system (not shown) also delivers fuel, e.g., natural gas, to the carburetor 12 by ways known to those skilled in the art. The carburetor 12 mixes the air and fuel, forming an air/fuel mixture.
[0010] The air/fuel mixture passes through a restricting device, such as a throttle plate 14 . The throttle plate 14 controls the volume of the air/fuel mixture that passes by ways known to those skilled in the art. In embodiments of the invention, the throttle plate 14 location may be varied from what is shown in FIG. 1. For example, it may be after, rather than before an aftercooler.
[0011] In embodiments of the invention that include an aftercooler 16 , such as a separate circuit aftercooler (“SCAC”), the combustion air/fuel mixture may be cooled, such as by: 1) passing the air/fuel mixture through the inside of a heater exchanger and ambient air passing over the outside (shown in FIG. 1); or 2) a cooled water passing through the inside of the heat exchanger and the contained air/fuel mixture passing over the outside of the heat exchanger core. Either system typically has a thermostat 18 to control the air/fuel mixture temperature to the engine. For SCAC system 1 (generally referred to as Air-to-Air Aftercooler (although for gaseous fueled low pressure units it should be more properly be called Air-to-Air/Fuel Mixture Aftercooler), the first thermostat 18 diverts none, some, or all of the air/fuel mixture through the aftercooler for cooling depending on the temperature of the air/fuel mixture at the first thermostat 18 . In one embodiment of the invention, the first thermostat 18 is set for 43 degrees Celsius.
[0012] In other words, the first thermostat 18 will send all of the air/fuel mixture through the aftercooler 16 if the temperature of the air/fuel mixture is greater than 43 degrees Celsius. If the temperature of the air/fuel mixture is less than 43 degrees Celsius, the first thermostat 18 will cause at least some of, and more typically all of the air/fuel mixture to bypass the aftercooler 16 , through a first bypass path 20 .
[0013] In other embodiments of the invention there are variations of this type of aftercooler 16 that are not thermostatically controlled and generally do not vary engine power based on ambient conditions.
[0014] Both the air/fuel mixture from the aftercooler 16 and the first bypass path 20 typically enter an inlet manifold 22 and a combustion chamber (not shown) of an engine 24 . As mentioned above, the engine 24 may be any of a variety of engines known to those skilled in the art, including and not limited to natural gas, turbines, diesel, and gasoline engines.
[0015] The second SCAC system described above may operate similarly except the cooling water circuit to the aftercooler 16 is thermostatically controlled. In this embodiment, the air/fuel mixture is not controlled or diverted through the first bypass path 20 .
[0016] The end result in many prior art engines is that the temperature of the air/fuel mixture to the inlet manifold 22 has been predetermined to a relatively high amount based on generally a worst case expected ambient condition. This method “mechanically” restricts the engine to a less than true maximum power output.
[0017] After combustion, the exhaust air and other combustion products exit the engine 24 via an exhaust path 26 by ways known to those skilled in the art.
[0018] In embodiments of the invention, a heat exchanger, such as a radiator 28 , may be coupled with the engine to reduce the temperature of the engine 24 . Other types of heat exchangers known to those skilled in the art may also be used.
[0019] Typically water, e.g., jacket water, or a mixture of water and other temperature conductive fluids, are flowed through a jacket (not shown) of the engine 24 via a pump 30 . A second thermostat 32 is typically used to make the jacket water bypass the radiator 28 via a second bypass path 34 when the jacket water temperature is below some predetermined temperature, such as 90 degrees Celsius. Other temperatures may be selected as appropriate.
[0020] In some embodiments of the invention, the radiator 28 may include portions of the aftercooler 16 by ways known to those skilled in the art. Alternately, the aftercooler 16 may use a separate heat exchanger (not shown, but described above as SCAC system 2 ).
[0021] A throttle plate control system 36 typically controls the volume of the air/fuel mixture that the throttle plate 14 allows to pass, e.g., via the position of the throttle plate 14 . In some embodiments of the invention, the throttle plate control system 36 may include an ambient air temperature sensor 38 that determines, e.g., calculates or measures, the ambient air temperature, and transmits a temperature signal TEMP indicative of the ambient air temperature.
[0022] In embodiments of the invention the throttle plate control system 36 may include a humidity sensor 40 that determines the relative or specific humidity of the ambient air and transmits a humidity signal HUMIDITY indicative of the humidity.
[0023] In embodiments of the invention the throttle plate control system 36 may include an inlet manifold pressure sensor 42 that determines the pressure of the air in the inlet manifold 22 and transmits an inlet manifold pressure signal IMPRESS indicative of the pressure.
[0024] In embodiments of the invention the throttle plate control system 36 may include an inlet manifold temperature sensor 44 that determines the temperature of the air or air/fuel mixture in the inlet manifold and transmits a temperature signal IMTEMP indicative of the temperature.
[0025] In embodiments of the invention the throttle plate control system 36 may include a detonation sensor 46 that determines when a detonation condition occurs during an ignition of the engine, and transmits a detonation signal DET indicative of the detonation. The detonation sensor 46 may, for example, detect vibrations of the engine, with detonation typically causing different vibration characteristics in the engine than normal ignition events do.
[0026] In embodiments of the invention the throttle plate control system 36 may include a jacket water temperature sensor 48 that determines the temperature of the jacket water and transmits a jacket water temperature signal JWTEMP indicative of the jacket water temperature.
[0027] A control device, such as a microcontroller or microprocessor 50 may be coupled with one, some, or all of the above sensors to receive their respective signals. The microprocessor 50 processes the respective signals and transmits a throttle position signal THROTTLE to the throttle plate as a function of the one, some, or all of the signals from the sensors. The throttle position signal THROTTLE controls the position of the throttle by ways known to those skilled in the art.
[0028] Generally, more power may be produced by the engine 24 when one, some, or all of the following operating conditions exist: jacket water temperature is low; inlet manifold temperature is low; inlet manifold pressure is high; detonation is not occurring; ambient temperature is low; humidity is high; and aftercooler temperature is low. Often these operating conditions will be better than the worst case operating conditions, and therefore allow for more power to be produced than the otherwise predetermined set maximum power rating of the engine 24 .
[0029] However, many conventional natural gas engines do not take advantage of these better than worst case conditions, and continue to command a throttle position THROTTLE as if the worst case operating conditions did exist, thereby resulting in the delivery of less power from the engine than it is capable of. Further, many conventional natural gas engines have a thermostat for the aftercooler and radiator that prevents the combustion air/fuel mixture temperature or the jacket water from being as low as they could be. For example, a unit with a 54 degrees Celsius thermostat installed in the SCAC aftercooler circuit (version 2 SCAC system) may provide on the order of 60 C inlet manifold air temperature.
[0030] However on cooler days the water temperature from the SCAC radiator (part of 28 ) could be lower than 54 C. A lower water temperature in the aftercooler circuit would reduce the inlet manifold air temperature and could increase engine power capability. In this example, however, even if the ambient conditions could cool the aftercooler water to a lower temperature the aftercooler thermostat 18 would still send 54 C water through the aftercooler core and thus the inlet manifold air temperature would not change.
[0031] Similarly, for version 1 of the SCAC system in a prior art system, if the temperature of the air/fuel mixture is below the rating for the first thermostat 18 , the air/fuel mixture may bypass the aftercooler 16 , even if the ambient conditions would allow the aftercooler 16 to cool the air/fuel mixture below the rating of the first thermostat 18 .
[0032] This lost cooling equates to lost power. By selecting a lower temperature thermostat, such as a 32 degrees Celsius, the aftercooler temperature may use this additional cooling capability. Other temperature thermostats may be used as appropriate. The thermostat 32 for the radiator may be selected similarly.
[0033] When the microprocessor 50 detects operating conditions that are better than worst case, as indicated by the various signals from the sensors, the microprocessor 50 commands the throttle position to a more open position, thereby allowing the engine 24 to produce power in excess of its otherwise worst case maximum power rating.
[0034] Further, with many natural gas engines, the throttle plate 14 is never commanded beyond 90-95% for its worst case maximum power. Thus, typically an extra 5-10% of the air/fuel mixture can be made available to the combustion chamber of the engine 24 . This 5-10% may now be used due to the further opening of the throttle plate 14 .
INDUSTRIAL APPLICABILITY
[0035] In operation, the respective sensors determine the operating conditions of the engine 24 . The microprocessor 50 processes the respective signals from the sensors. The microprocessor 50 may signal the equipment that is powered by the engine 24 , e.g., the driven equipment, that more power is available. The driven equipment may then request the higher power capability and the microprocessor 50 then commands the throttle 14 to a position as a function of the signals from the sensors and the driven equipment. Unlike many conventional throttle plate control systems, the throttle plate control system 36 may command the throttle position to full (100%) open, or as close thereto as is appropriate when the engine operating conditions are better than worst case. This may result in additional power being available from the engine 24 . Further, additional cooling of the air/fuel mixture may be achieved by appropriate selection of the thermostats for the aftercooler 16 .
[0036] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
|
Methods and apparatus for controlling an engine having a first maximum power rating based on at least a first predetermined operating condition of the engine. A first sensor transmits a first signal as a function of the engine operating at a predetermined operating condition other than the first predetermined operating condition. A control device receives the first signal and transmits a power signal to the engine as a function of the first signal. The power signal may, by itself, or in conjunction with other signals, cause the engine to produce a quantity of power in excess of the first maximum power rating.
| 5
|
BACKGROUND
[0001] 1. Field of the Disclosure
[0002] The disclosure herein relates to mills for milling casings in a wellbore and specifically to mills that can be sheared when trapped (also referred to herein as stuck or lodged) in the wellbore to remove the service strings utilized to convey such mills in the wellbores.
[0003] 2. Background of the Art
[0004] Wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Modern wells can extend to great well depths, often more than 15,000 ft. A wellbore is typically lined with casing (a string of metal tubulars connected in series) along the length of the wellbore to prevent collapse of the formation (rocks) into the wellbore. A variety of devices are installed in the wellbore to produce the hydrocarbons from the formation surrounding the wellbore from one or more production zones. Sometimes it is necessary to mill a part of the casing to perform a downhole operation or for other reasons. The casing section remaining above the milled portion is sometimes removed from the wellbore. To perform a milling and retrieving operations, a tool (commonly referred to as a mill, with cutting members (also referred to as knives or blades) is typically conveyed into the casing by a service string to mill a certain length of the casing at a desired location. Sometimes the mill becomes trapped or lodged in the casing, such as in the case of cutting members not retracting after the milling operation or due to another downhole condition. Some mills include a shear mechanism on the upper section of or above the mill that allows an operator to over-pull the service string to cause the mill to separate from the service string and drop in the wellbore, which allows the operator to retrieve the service string to the surface. It is also desirable not to leave tools in the wellbore or minimize the size of such debris left or dropped in the wellbore so as to avoid performing secondary operations to remove tools left in the wellbore before performing operations needed at a later time or to not obstruct flow of fluids flowing through the wellbore or for other reasons.
[0005] The disclosure herein provides apparatus that provides, among other things, mills with shear mechanism that allows disconnecting cutting members from the mill when such mills are trapped in the wellbore.
SUMMARY
[0006] In one aspect, a mill for milling a casing is disclosed that in one non-limiting embodiment includes a plurality of radially extendable cutting members on a body, an activation device that extends the cutting members radially outward from the body upon application of a hydraulic pressure to the activation device and mechanically retracts the cutting members upon removal of the hydraulic pressure from the activation device, and wherein the cutting members are separable from the body.
[0007] In another aspect, a method of milling a casing in a wellbore is provided that in one non-limiting embodiment includes: conveying a string in the wellbore that includes a mill that contains a plurality of radially extendable cutting members on a body that are separable from the body of the mill and an activation device that extends the cutting members radially outward from the body upon application of a hydraulic pressure to the activation device and mechanically retracts the blades upon removal of the hydraulic pressure from the activation device; extending the cutting members to engage with the casing; rotating the mill while applying a pull force on the mill to mill the casing; and applying a pull force on the mill to disconnect the cutting members when the mill is trapped in the wellbore.
[0008] Examples of the more important features of an apparatus and methods have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features that will be described hereinafter and which will form the subject of the claims.
BRIEF DESCRIPTION OF THE DRAWING
[0009] For a detailed understanding of the apparatus and methods disclosed herein, reference should be made to the accompanying drawing and the detailed description thereof, wherein like elements are generally given same numerals and wherein:
[0010] FIG. 1 shows a mill in the run-in position, according to one non-limiting embodiment of the disclosure;
[0011] FIG. 2 shows the mill of FIG. 1 while in the milling position;
[0012] FIG. 3 shows the mill of FIG. 1 in a trapped position in the wellbore; and
[0013] FIG. 4 shows portion of the mill of FIG. 3 after the cutting members have been disconnected or sheared off from the body of the mill.
DETAILED DESCRIPTION
[0014] FIG. 1 shows a mill 100 in the run-in position, according to a non-limiting embodiment of the disclosure. The mill 100 includes a body 110 having a number of cutting members or knives 120 radially arranged around the body 110 . Each such knife is radially expandable outward about its pivot 122 . In FIG. 1 , the knives 120 are shown in the retracted or run-in position. The number of knives 120 varies depending on the application and is typically between six (6) and ten (10), wherein such knives are equally spaced around the body 110 . The mill includes a top sub 125 for connection to a service string (not shown) and includes a fluid passage 126 for supplying a suitable fluid to the mill for activating the mill, i.e. radially expanding the knives 120 . The mill 100 further includes a mill activation device or mechanism that includes a piston 130 that acts on a compression spring 135 . The piston 130 is supported or held by a retainer 132 on its downhole end 133 . An upper extension tube 136 moves upward and downward in a seal bearing 137 in the top sub 125 as the piston 130 moves upward and downward in its chamber 138 . A mandrel assembly 140 coupled to a lower end of the piston is configured to radially extend outward the knives 120 . The mandrel assembly 140 includes an extension rod 142 with its upper end 142 a connected to the piston 130 and its lower end 142 b connected to a knife opening device 144 . A keeper 150 and a knife holder 152 hold the knives 120 in the body 110 . The method of activating the blades 120 is described below. A knife tang 160 is provided to cause the knives to retract to their positions shown in FIG. 1 . The knife tang 160 is connected on the bottom of the knives 120 and retracts as the piston 130 moves downward when the fluid pressure applied onto the piston 130 is removed. Thus, in the embodiment of FIG. 1 , the knives 120 are hydraulically extended (pressure of fluid 101 ) and mechanically retraced (by spring activated knife tang 160 ). A shear member 170 , including, but not limited to a shear ring, pin and screw retained in the lower part 110 a of the body 110 by a shear retainer 172 .
[0015] FIG. 2 shows the mill of FIG. 1 in the milling position. Referring to FIGS. 1 and 2 , to activate the mill 100 to mill a casing 180 in a wellbore 103 , a fluid 101 under pressure is supplied to the mill 100 . The fluid 101 causes the piston 130 to move upward (left in FIG. 2 ), which compresses spring 135 , which causes the upper extension tube 136 , the extension member, such as rod, 142 and the knife expansion device 144 to move upward. The upward movement of the knife extension device causes the knives 120 to expand radially outward about their respective pivots 122 , as shown in FIG. 2 . As long as the fluid pressure is applied, the piston 120 remains in the upward position and the compression spring 135 remains compressed, as shown in FIG. 2 . To mill the casing 180 , knives 120 are rotated by a motor (not shown) in the string or by rotating the string 190 with upward tension on the mill 100 . When the fluid pressure is removed, the piston 130 moves to the right and the knife tang 180 causes the knives 120 to retract as shown in FIG. 1 . In the event one or more knives 120 do not retract, the string 190 cannot be moved upward to retrieve the mill 100 from the wellbore. The method of shearing a portion of the mill 100 to retrieve the string 190 are described below in reference to FIGS. 3 and 4 .
[0016] FIG. 3 shows the piston 130 in the downward position as in FIG. 1 although the fluid pressure has been removed. The mandrel assembly 140 , including the extension rod 142 and expansion device 144 , also move downward with the piston 130 and attain the same position as in FIG. 1 . When one or more knives 120 do not retract, such knives will remain extended and behind the casing 180 as shown in FIG. 3 . To pull the string 190 out of the wellbore, the string 190 is pulled with a pull force that exceeds the shear strength of the shear member 170 , causing the shear member 170 to shear. Shearing of the shear member 170 causes the shear retainer 172 along with the knives 120 to separate or disconnect from the body 110 . The mill portion 188 after the blades 120 have been separated is shown in FIG. 4 . The string 190 along with the mill portion 188 can now be retrieved from the wellbore by pulling up the string 190 . The mill 100 described herein may also be configured for use for milling the casing in the downward direction. In such a case, to mill the casing 104 , a push force is applied while rotating the cutting members 120 to mill the casing 104 .
[0017] The foregoing disclosure is directed to the certain exemplary non-limiting embodiments. Various modifications will be apparent to those skilled in the art. It is intended that all such modifications within the scope of the appended claims be embraced by the foregoing disclosure. The words “comprising” and “comprises” as used in the claims are to be interpreted to mean “including but not limited to”. Also, the abstract is not to be used to limit the scope of the claims.
|
A mill for milling a casing in a wellbore is disclosed that in one non-limiting embodiment includes a plurality of radially extendable cutting members on a body, an activation device that extends the cutting members radially outward from the body upon application of a hydraulic pressure to the activation device and mechanically retracts the blades upon removal of the hydraulic pressure from the activation device, and wherein the cutting members are separable from the body
| 4
|
BACKGROUND OF THE INVENTION
This invention relates generally to the field of automated apparatus for handling electronic circuit components and, more particularly, to automated apparatus for use in the art of burning-in circuit components prior to their distribution and use. Still More specifically, this invention is directed to automated insertion and removal of electronic integrated circuit ("IC") packages or devices into or out of sockets on printed circuit boards, especially printed circuit boards used for burn-in testing of IC packages or devices and called "Burn-in Boards" or "BIB's".
IC packages or devices (for brevity, hereinafter both being referred to simply as "devices") may be classified according to force required to insert them into their sockets. Direct entry devices require insertion force and include such devices as dual in-line packages ("DIPs"), which comprise a parallelpiped body portion typically having from four to sixty four electrical leads of a generally L-shaped cross-section extending out and down from the opposing sides of the body. The sockets mounted on the burn-in boards may therefore include socket contact slots for receiving electrical leads on DIPs. Another direct entry device is the small outline J-lead chip carrier ("SOJ").
Zero insertion force devices do not require force to insert them into their sockets ("ZIF" sockets). Zero insertion force devices generally are surface mounted devices ("SMD's"). SMD's are gaining in popularity for packaging integrated circuits, because they mount directly to the surface of the printed circuit board, which eliminates expense of drilling mounting holes through the board. SMD's also are in some instances much smaller than DIP's, allowing tighter packaging densities. SMD's include small outline integrated circuits ("SOIC's"), plastic lead chip carriers ("PLCC's"), ceramic leaded chip carriers ("CLCC's"), leadless chip carriers ("LCC's") and, plastic quad flat packs ("PQFP's"). The SOIC also comprises a generally parallelpiped body portion having electrical leads extending from opposing sides of the body. The electrical lead may have either a J-shaped or a S-shaped ("gull wing") cross-section. The PLCC, CLCC, LCC and PQFP's have bodies which have square or rectangular geometry with a relatively thin cross section, giving these IC packages an overall wafer-shaped appearance. In the usual construction, the PLCC, CLCC and PQFP have multiple electrical leads positioned flush with or bent into close proximity with the body of the package, while the LCC has conductive coatings applied at selected areas on the major body surfaces.
SMD's mount to the surface of the boards in SMD sockets. In these sockets, the SMD's lay on the surface of a support in the socket instead of being inserted into slots in the socket as are DIP's. Spring biased socket contacts press against the SMD's leads that extend from the sides of the SM body. One basic type of SMD socket is the ZIF socket in which the spring biased socket contacts are spread apart by depressing a socket lid to allow clearance for SMD placement and removal. Another type is a so called ZIF "over-the-top" cover socket which is hinged to open the socket lid for SMD placement or removal and which includes a latch to secure it shut.
As is well known and detailed somewhat more in my earlier patent, U.S. Pat. No. 4,817,273 and in the references cited therein, IC devices are mass-produced and installed in electronic circuits used in highly sophisticated, complex and costly equipment. As with many mass-produced products, IC devices are prone to failure, in some cases within the first 1000 hours of operation. The complexity of equipment within which such devices are installed makes post-installation failures highly undesirable. Quality and dependability are enhanced substantially by early detection of those IC devices likely to fail in the first few hours of operation, prior to installation of the devices in electronic equipment. One of the methods for detecting flawed IC devices is referred to generally as "burn-in". Burn-in refers generally to the technique in which IC packages or devices are stressed, and sometimes tested, within their physical and electrical limits prior to their sale or distribution, so that those devices likely to become early failures in complicated equipment can be discovered, and so that IC devices, in some cases, can be graded and sorted according to performance specifications. The burn-in technique generally includes loading the IC devices into sockets on burn-in boards; placing the burn-in boards in a chamber whose environment, particularly temperature, is controllable; applying electrical test signals to the boards while subjecting the IC devices to the maximum temperature reading for them; removing the burn-in board from the chamber; and unloading the IC devices from the burn-in boards. In addition, it is sometimes desirable to sort the IC devices by performance grade after burn-in.
The burn-in test processes however, although successful in reducing expenses associated with flawed IC devices, are not themselves without expense. Substantial capital expenditures are necessary to purchase or to construct burn-in chambers, burn-in boards, and test equipment. Personnel must be employed and trained to operate the equipment and to monitor the time-consuming processes. So substantial are the investments that independent businesses provide burn-in and test services to a variety of manufacturers. Cost effectiveness of the burn-in and test processes is therefore essential.
One means of improving the cost effectiveness of the burn-in and test processes is to reduce labor expenses and to improve efficiency and quality control through the use of automation. Accordingly, efforts have been made to automate various aspects of the burn-in process, as shown, for example, by U.S. Pat. Nos. 4,320,805; 4,439,917; 4,584,764; 4,567,652; 4,660,282; 4,780,956; 4,781,494; 4,801,234; and 4,817,273; and also West Germany Patent Application DE 8,626,502 and Great Britain Patent Application GB 2,157,275A.
Automated handling enables the use of a computer to track and document the progress of each IC devices through the burn-in process. In situations involving a high volume of IC devices for burn-in, automated handling equipment may be used to achieve a higher through-put of IC devices more efficiently than could be achieved otherwise. A single automated loader, for example, can easily replace a goodly number of very efficient employees assigned to the tedious task of loading burn-in boards. In any situation, automated handling equipment provides improved reliability and consistency of work product.
None of the prior methods of automated loading or unloading provide the advantages of my present invention, the features and benefits of which will become apparent from the detailed descriptions which follow after I first summarize the invention.
SUMMARY OF THE INVENTION
In accordance with this invention, apparatus and method are provided for loading and unloading IC devices into and out of sockets on printed circuit boards, suitably burn-in boards. The apparatus comprises a support; a carrier system translationally moveably affixed to the support for carrying a printed circuit board horizontally in a first horizontal straight line axis; in a preferred aspect, a device staging system including a longitudinal straight slideway having a first end and a second end pivotally affixed to said support and pivotal at least to (i) a first position in which said first end is lower than said second end and (ii) a second position in which said first end and the said second end are at the same level, for gravity feeding IC devices from the second end of the slideway to the first end when the slideway is pivoted to the first position to stage the devices for pickup in said second position; a pickup and place system translationally moveably affixed to the support for (i) vertically picking up a plurality of IC devices from the first end of the slideway when the slideway is in the second position, (ii) horizontally carrying the devices above the carrier system in a second horizontal straight line axis perpendicular to the first horizontal straight line axis, and (iii) vertically placing the IC devices each into separate sockets on the printed circuit board; and a control system for operating and controlling the device staging means, the carrier means and the pick up and place means. Preferably, the pickup and place system includes structure for extracting devices from sockets on the printed circuit board and placing the devices on the slideway when the slideway is in the second position, and preferably the device staging system is pivotable to a third position in which the second end is lower than the first end are for unloading the printed circuit board.
The invention involves a process of loading IC devices into sockets on a printed circuit board, including supporting a printed circuit board horizontally; supplying a source of IC devices in longitudinal orientation with a longitudinal straight slideway having first and second ends and pivotal to the aforementioned first position, in which the first end is lower than to the aforementioned second end, and to a second position, in which the first and second ends are at the same level, the first end of the slideway including in the slideway a plurality of longitudinally arrayed vacuum ports, the slideway also having a gating vacuum port between the second end and the longitudinal array of vacuum ports in the first end; pivoting the slideway to the aforementioned first position to slide IC devices from the IC source onto and down the slideway under the force of gravity; applying vacuum to one or more of the ports in the first end of the slideway to arrest descent of the devices in the slideway; applying vacuum to the gating port to arrest the device over the gating port and any trailing devices in the slideway and removing vacuum at the ports in the first end to slide devices below the gating port to positions over all the ports in the first end available to be filled, then reapplying vacuum to secure the devices over the ports; pivoting the slideway to the second position; picking up vertically a plurality of devices from over the ports in the first end of the slideway upon release of vacuum to these ports; the printed circuit board upon the support horizontally in a first straight line axis to a predetermined position along the first axis; and transporting the plurality of devices horizontally over the printed circuit board in a second straight line axis, perpendicular to the first straight line axis, to a predetermined position along the second straight line axis; and vertically placing the plurality of devices in sockets on the printed circuit board.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a loader/unloader apparatus constructed in accordance with the principles of the present invention;
FIG. 2 shows a front elevational view of the loader/unloader apparatus depicted in FIG. 1;
FIG. 3 shows a side elevational view of the loader/unloader apparatus along the line 3--3 in FIG. 2;
FIG. 4 shows a partial rear view particularly of the load/unload plant head systems, tube transport systems, and device staging systems along the line 4--4 in FIG. 3;
FIG. 5 shows a partial overhead plan view along the line 5--5 of FIG. 2, with portions removed to disclose pertinent portions of the apparatus, and particularly shows the device staging portions of the apparatus in pivot ready position;
FIG. 6 is the same view as FIG. 5, and shows the device staging apparatus in tube loading position;
FIG. 7 is a partial side elevational view of the apparatus taken along the line 7--7 of FIG. 5 in pivot ready position;
FIG. 8 is a partial side elevational view taken along the line of 8--8 of FIG. 6, and accordingly shows in elevation the device staging portion of the apparatus in tube loading position;
FIG. 9 is a side elevational view comparable to FIG. 7 and FIG. 8, and shows the device staging portion of the apparatus pivoted to stage devices for loading in accordance with the invention, and conversely in shadow, to illustrate the device staging apparatus pivoted to a tube unloading position;
FIG. 10 is a side elevational view and partial cross-section of a load/unload plant head assembly;
FIG. 11 is a frontal elevational view of the load/unload plant head assembly of FIG. 10, with a portion thereof in cross-section along the line 11--11 of FIG. 10;
FIG. 12 is a bottom view of the load/unload plant head assembly, taken along the line 12--12 of FIG. 10;
FIG. 13 is the same view of the lower portion of FIG. 11 that is in cross-sectional view, but in a different operating position;
FIG. 14A is a front elevational view of the load/unload plant head assembly positioned with the device staging assembly for loading or unloading steps;
FIG. 14B is the same view of the load/unload head assembly of FIG. 14A, with the assembly in load/unload position over a socket on a burn-in board;
FIG. 14C is the load/unload plant head assembly of FIGS. 14A and 14B shown in device planting positioned over a socket on a burn-in board; ,
FIG. 15 is a plan elevational view of the burn-in board or tray carrier assemblies and drive systems with portions of the support platform for the carriers removed to disclose pertinent portions of the apparatus;
FIG. 16 is a lateral or X-axis cross-sectional view of the carrier and support platform of FIG. 15 taken along the line 16--16 of FIG. 15;
FIG. 17 is a cross-sectional view of the carrier and support apparatus of FIG. 15 taken along the line 17--17 of FIG. 15; and
FIG. 18 is a schematic of the control system of the apparatus.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The architecture of the inventive structural concept permits one unit of cooperating systems of the invention to be joined with another like unit of cooperating systems to maximize flexibility and throughput in one machine. The preferred embodiment described in this portion of the specification of the invention benefits from this architectural advantage and arranges the joined inventive units bilaterally, so the machine has a left side and a right side as viewed from the front.
Because of this bilateral dualism, this portion of the specification adopts a convention in aid of brevity of detailed description. In this convention, structure on the left side of the apparatus and numbered 100 or greater has an even number, and like structure on the right side has an odd number which is one integer higher than the even number for the same structure on the left side. For example, item 103 on the right side corresponds to item 102 on the left side. Cooperating systems making up a left side unit of operation are "A" systems, e.g. system 100A, and cooperating systems making up a right side unit of operation are "B" systems, e.g., system 100B.
Referring to FIG. 1 for orientation, reference numeral 10 indicates a bilateral loader/unloader apparatus for automatically loading and unloading integrated circuit packages or devices into sockets 11 of one or more burn-in boards 12. Loader/unloader apparatus 10 includes a support structure indicated generally by reference numeral 20, dual burn-in board or tray carrier systems indicated generally by reference numerals 100A and 100B, dual load/unload pick and place plant head systems indicated generally by reference numerals 200A and 200B, dual tube transport systems indicated generally by reference numerals 300A and 300B, and dual device staging systems indicated generally by reference numerals 400A and 400B.
Apparatus 10 is operated by a system controller 500 the centerpiece of which is a microprocessor 501. The control system for apparatus 10 is illustrated in block diagram in FIG. 18, and is discussed in more detail hereinbelow.
Referring still to FIG. 1, computer 510 with keyboard 502 and monitor 504 is supported on a retractable pullout shelf 14 shown pulled-out at the front of loader/unloader apparatus 10. Device staging systems 300A and 300B and tube transport systems 400A and 400B are toward the rear of loader/unloader apparatus 10. The front-to-rear or rear-to-front direction for apparatus 10 is denominated herein as the "Y" axis direction. The axis which is perpendicular to the "Y" axis in the plane of the paper of FIG. 1 is denominated herein as the "X" axis direction. Thus, "Y" axis movement is a front-to-back and back-to-front movement, and "X" axis movement is a lateral movement, right-to-left or left-to-right. Movement which is perpendicular to the plane of the paper of FIG. 1 is denominated "Z" axis movement, and represents up and down or vertical movement.
With this general orientation of apparatus 10, the supporting structure and operating systems of apparatus 10 are now detailed.
Support Structure
Referring to FIGS. 2 and 3, the support structure 20 of loader/unloader apparatus 10 includes a bilateral support base indicated generally by reference numerals 22 and 23 and a support platform indicated generally by reference numeral 24. Each of support bases 22 and 23 is generally comprised of a framework 26 supported on feet 28 and enclosed by sheet metal panels affixed at the front, back, sides and bottom. FIG. 2. shows left front panel 30 and right front panel 32, and FIG. 3 shows left side panel 34. The closures of framework 26 by the front, back, side and bottom panels provide left and right cabinets in the support base. These cabinets house the various logic controllers, relays, pneumatic and vacuum pressure valving and sensors, and other systems as hereinafter described. Rigidly connected to support bases 22, 23 is support platform 24. Support platform 24 includes frame work 36, left and right end panels 38 and 39, front panel 42, bottom panel 44, and top panel 46, all fastened suitably by welding or bolting to form a rigid enclosure. Top panel 46 contains four lateral slots, namely, front slot 48, intermediate slots 50 and 51, and rear slot 52. Through these slots pass supports to left carrier plate 101 and right carrier plate 102 as more particularly described below.
Burn-in-Board/Tray Carrier System
Referring now particularly to FIGS. 15, 16 and 17 in conjunction with FIGS. 1, 2 and 3, the drive systems of burn-in board or tray carrier systems 100A and 100B are described. Referring first to FIG. 16, left rear, rear X-axis shaft support mount 104 and right rear, rear X-axis shaft support mount 105 are rigidly affixed, respectively, to left and right end panels 38 and 39, and to bottom panel 44, and supportingly mount rear X-axis support shaft 60. Similarly, left front, front X-axis shaft support mount 106 and a right front, front X-axis shaft support mount (not shown) supportingly mount front X-axis support shaft 61. Referring to FIG. 15, right carrier plate 103 is slidingly mounted on front X-axis support shaft 61 by right carrier plate left front bearing mount 109 and by right front bearing mount 111, and is slidingly mounted on rear X-axis support shaft 110 by leftrear bearing mount 113 and right rear bearing mount 115. Bearing mounts 109 and 111 pass through slot 48 of top panel 46, and bearing mounts 113 and 115 pass through slot 52. Similarly, front left and right bearing mounts 108 and 110 slidingly mount left carrier plate 102 on front X-axis shaft 61, and left and right rear bearing mounts 112 and 114 slidingly mount carrier plate 102 on rear X-axis support shaft 60. Front and rear X-axis shafts 61 and 60 provide a track on which carrier plates 102 and 103 may travel laterally left-to-right or right-to-left in an X-axis movement.
Positioning of right carriage plate 103 is controlled by right carrier plate drive motor 117, the shaft of which is coupled by flexible coupling 119 to rear X-axis ball screw shaft 121 which is supported by left rear screw shaft support bearing 123 and by right rear screw shaft support bearing 125. Rear ball nut 127 is threadingly engaged with rear X-axis ball screw shaft 121 and is affixed to ball nut mount 129 which in turn attaches to right carrier plate 103, passing through rear intermediate slot 50 in top panel 46. Similarly, positioning of left carrier plate 102 is controlled by left carrier plate drive motor 116, the shaft of which is coupled by flexible coupling 118 to front X-axis ball screw shaft 120 mounted on left and right front screw shaft support bearing mounts 122 and 124, respectively. Front X-axis ball screw shaft 120 threadingly engages ball nut 126 affixed to ball nut mount 128 attached to carrier 102.
Right carrier plate 103 is provided linear X-axis movement by drive motor 117 as ball nut 127 attached by mount 129 to right carrier plate 103 rides the screw flight of ball screw shaft 121 according to the clockwise or counter-clockwise direction of rotation imparted to shaft 121 by motor 117. Similarly, left carrier plate 102 is given precise linear X-axis placement by clockwise or counter-clockwise rotation imparted by drive motor 116 to ball screw shaft 120 acting on ball nut 126. Drive motors 116 and 117 are brushless direct current servo motors, whose direction of rotation is reversible and whose degree and rat of rotation is accurately controlled according to step pulses generated by the system controller. The motors include an integral position resolver which is coupled electrically to the controller to provide positive feed back for position control. A suitable such drive motor is Compumotor model 57-120 available from Parker Hannisin Corporation, Compumotor Division, 5500 Businesspark Drive, Rohnert Park, Calif. 94928. Suitably the ball screws may have a precision ground 3/4 inch diameter with a 1/2 inch pitch.
Affixed to bottom panel 40 by mounts 131 and 133 are optoelectronic position sensors 135, 137 and 139, each having a channel formed in their upper surface for accepting passage therethrough of a downwardly extending indicator flag 141 which is rigidly attached to bearing mount 129 of carrier 103. One upright of the channel supports the light emitter and the other the light detector. When flag 141 passes through the channel of one of the sensors 135, 137 and 139 as carrier 103 moves along an X-axis imposed by support shafts 60 and 61, the flag interrupts the light across the channel from the emitter to the detector of the photosensor and this interrupt triggers a signal for carrier 103. Sensor 135 indicates a limit of travel of carrier of 103 to the left, and sensor 137 indicates a limit of travel of carrier 103 to the right. Sensor 139 indicates a home position. Placement of sensor 139 is arbitrary, so long as it is between limit sensors 135, 137. When placement of sensor 139 is fixed, a signal of limit sensor 135 corresponds to a number of rotations of ball screw shaft 121 in one direction (counter-clockwise from home), and a signal of limit sensor 137 corresponds to a number of rotations of ball screw shaft 121 in the other direction (clockwise from home). Thus, positions along the X-axis of the support shafts for carrier 103 are a specific increment from home position.
A suitable optoelectronic sensor for use as limit sensors 135, 137 and home sensor 139 is slotted optical switch type OPB88OT55 supplied by the Optoelectrical Division of TRW, Inc., 1207 Tappen Drive, Carrollton, Tex. 75008.
Burn-in board or tray carrier systems 100A and 100B include means for supporting, locating and securing the burn-in boards or trays they carry. Referring to FIGS. 1 and 2, carrier plate 102 of carrier system 100A includes guide rail pairs 142, 144 and 146. Guide rails 142 and 146 have U-shaped slots that face guide rail 144. Guide rail 144 is H-shaped, with opposed slots respectively facing guide rail 142 and guide rail 146. Guide rails 143 and 146 are spring loaded. These facing slots of the guide rail pairs slidingly accept a burn-in board 12. Board 12 is inserted in the opposing slots of guide rails 144, 146 from the front of apparatus 10 (in the guide rail orientations illustrated) and pushed in the slots in a front-to-back movement until board 12 reaches an adjustable stop which comprises a threaded member having stop head 174 threaded into cross member 176. When board 12 is inserted in the opposing slots of guide rails 144, 146 and pushed in the slots back to stop head 174, the coil springs (not shown) in guide rail 146 are compressed an react by exerting a lateral force on board 12, so when board 12 is advanced to stop head 174, the board is held fast on carrier plate 102.
Provision is made in carrier system 100A and 100B to support the underside of burn-in board 12 which is to be located and secured on carrier plates 102 and 103. In the embodiment depicted, use of guide rails to locate and secure the burn-in boards raises the burn-in board off the surface of the carrier plates 102 and 103, and supports are provided to support the burn-in boards from beneath to reduce board flexing when devices are loaded into or unloaded from the sockets 11 on the top surface of the boards. The provision of this support is best viewed in FIG. 1 taken in conjunction with FIGS. 14B and 14C. Referring to FIG. 1, a plurality of recesses 154 and 156 are provided in carrier plate 102 between guide rails 142, 144, and similarly, but not seen, between guide rails 144, 146; in carrier plate 103, similar recesses are provided between guide rails 143, 145 (not visible in FIG. 1), and at reference numerals 159, 161 between guide rails 145, 147. In FIGS. 14B and 14C, reference numeral 159 indicates a recess between guide rails 145, 147. Using the same reference numerals to indicate burn-in board support structure visible in FIG. 1 which is identical to the burn-in board support structure seen in FIGS. 14B and 14C, elongated support bar 163 has pivot pins 165, 167 longitudinally affixed centrally at its base. Pins 165, 167 are received in pivot holes (not shown) in the lateral margins of recess 159. As seen in FIG. 14C, a leaf spring 169 is situated between the front and rear margins of recess 159 in relaxed engagement with the base of support bar 163. The dimension between the rotational axis of pins 165, 167 and the nose 171 of bar 163 is selected such that in the relaxed position of spring 169 nose 171 of bar 163 supports the underside of burn-in board 12. An X-axis displacement of nose 171 of support bar 163 (as illustrated in FIG. 14B) pivots bar 163 about the rotational axis of pins 165, 167, pressing the downwardly rotated edge of the base against spring 169 and deforming spring 169 from its relaxed position. When burn-in board 12 is inserted in the facing channel of guide rails 145, 147 and slid into position, bar 163 is pivoted out of its upright position by board stiffeners which depend from the leading edge of the burn-in board and come into contact with bar 163. When the board stiffeners are moved past contact with support bar 163, the work stored by deformation in spring 169 by deformation urges bar 163 back into its upright position so that nose 171 of bar 163 then supports the underside of burn-in board 12.
Pick and Place Load/Unload Plant Head System
As may be seen by reference to FIG. 3 taken with FIGS. 1 and 2, load/unload plant head system 200A and 200B is surmounted on platform 24 (for clarity only 200A is depicted in FIG. 3). Referring to load/unload plant head system 200A (like structure in load/unload plant head system 200B has one higher integer odd number, by the convention stated above), front mount 202 and rear mount 204 are secured, respectively at the front and rear of platform 24. Each supports an upper Y-axis support shaft 206 and a lower Y-axis support shaft 208. Journaled in front and rear mounts 202 and 204 between shafts 206 and 208 is Y-axis ball screw shaft 210. Referring to FIG. 1 in conjunction with FIG. 2, plant head bearing blocks 212, 214, 216 and 218 are slidingly mounted on support shafts 206 and 208. Bearing block 212 incorporates a ball nut 220 which is threadingly engaged on ball screw shaft 210. Bearing blocks 212, 214, 216 and 218 are united in a fixed spatial relationship by alignment plate 222. Alignment plate 222 is tailored for the dimensions of each particular burn-in board to space the plant heads correctly apart to fit the X-axis rows on the particular burn-in board 12. A set of bearing blocks 212, 214, 216 and 218 each mounting a plant head and coupled by alignment plate 222 is a plant head unit.
A brushless direct current servo drive motor 224 is supported by upper motor mounts 226a, 226b and lower mounts 228a, 228b onto load/unload plant head system rear mount 204. A flexible coupling 230 connects the shaft of drive motor 224 to ball screw shaft 210. Like drive motors 116 and 117, the shaft rotation of drive motors 224 and 225 is reversible and the degree and rate of rotation is precisely controllable by pulses to the motor generated by the system controller 500. As with drive motors 116 and 117, the precise clockwise or counter-clockwise shaft rotation control of drive motors 224 and 225 is translated by ball screw shafts 210 and 211, respectively, and ball nuts 220 and 221, respectively, into precise linear placement of the plant head units on the plant head bearing block mounts along the Y-axis shafts (block mounts 212, 214, 216 and 218 along Y-axis shafts 206 and 208 for motor 224 in plant head system 200A; block mounts 213, 215, 217 and 219 along Y-axis shafts 207 and 209 for motor 225 in plant head system 200B).
Load/unload plant head system 200A, also like carrier system 100A, makes use of optoelectic limit sensors 232a, 232b and home sensor 234 spaced apart on and supported by raceway 240 (the same optoelectric sensor as used for sensors 135, 137 and 139 is suitable). As with the optoelectronic sensors used in the X-axis for the carrier plate 103, the limit sensors 232a, 232b are triggered by an interrupt flag (flag 236 on bearing block 212) and signal a limit of excursion of the plant head on the Y-axis of support shafts 206, 208 over platform 24. The home sensor 234 is also triggered by flag 236 and is positioned between the limit sensors. All positions along the Y-axis of ball screw shaft 210 are a specific increment from the home position of the plant head unit on ball screw shaft 210.
Accordingly, from the above and foregoing description, based on the X-Y grid system imposed by X-axis travel for the carrier plates and Y-axis travel imposed for the pick and plant head system, any burn-in board of known rows and columns and socket spacing has a socket location defined as some incremental distance left or right from the X-axis home position of the carrier plate and some incremental distance in front of or behind the Y-axis home position of the plant head unit. With the X-axis and Y-axis home references set, system controller 500 calculates these incremental distances.
Plant head bearing block mounts 212-219 are internally configured with vacuum and air pressure passageways. Flexible tubing air and vacuum lines are connected with the vacuum and air passageways of each of these block mounts. The vacuum and air pressure tubing lines run to the block bearings mounts from horizontal raceways 240, 241, which they enter from the base cabinetry where the vacuum and air pressure control systems are situated. (The drawings do not illustrate the many vacuum and air pressure lines or electronic cablings employed in apparatus 10.) The vacuum and air pressure tubing from raceways 240, 241 are representatively indicated by the general reference numeral 299 in the drawings.
Referring now to FIGS. 10, 11, 12 and 13, a representative plant head 244 is depicted. In the description of this representative plant head assembly, the convention adopted above does not apply, that is, an odd number is not a like member to a next lower integer even number.
Plant head 244 comprises an air cylinder assembly 245, a mounting plate 246 and a socket opener assembly 247. Air cylinder assembly 245 includes air cylinder 248 attached by mounting bolt (not shown) to mounting plate 246. Air cylinder 248 is upwardly closed by cylinder plug 249 affixedly secured to cylinder 248 (by means not shown). Cylinder 248 and cylinder plug 249 have central openings through which pass a tubular piston rod 250 which contains a central conduit 251 along its axial length. Rod 250 fixedly mounts double acting piston 251 within chamber 252 (upper chamber portion 251a; lower chamber portion 252b) of cylinder 248. Air pressure in air cylinder 248 is sealed by O-rings 253, 254a, 254b and 255.
The lower extremity of piston rod 250 terminates in a threaded portion (not seen) on to which nut 256 and tubular pad assembly 257 are threadingly attached. Pad assembly 257 comprises both a first tubular member 258 having an upper nut portion 258a and a lower shaft portion 258b, and a second tubular member 259 supporting a vacuum pad portion 260. Upper nut member 258a is internally threaded to threadingly engage the externally threaded end of piston rod 250. Lower tubular member 258b is internally threaded to accept external threads on the tubular shaft of vacuum pad support member 259. The bore 261 of tubular pad assembly 257 is continuous with axial conduit 251 of rod 250. Also fitted on a portion of piston rod 250 extending below air cylinder 248 above the end of rod 250 is an adjustable stop 262 for precise limitation of the extent of retraction of rod 250 into air cylinder 248. Nut 256 acting with the nut structure of upper portion 258a permits pad assembly 257 to be adjusted and secured longitudinally along the exteriorly threaded end of piston rod 250 to a position which places vacuum pad member 260 a precise distance above sockets 11 on burn-in board 12.
Mounting plate 246 to which representative air cylinder assembly 245 attaches is in turn attached to the bearing blocks 212-219, bearing block 218 being identified merely as an exemplar in FIGS. 10 and 12. Mounting plate 246 is provided with internal vacuum and air pressure passageways which connect with internal passageways in the bearing blocks, for example, bearing block 218. An internal vacuum passageway (not shown) from bearing block 218 to mounting plate 246 connects at the top face of mounting plate 246 through nipple fitting 263 with flexible tubing 264, which connects through fitting 265 to conduit 251 of piston rod 250 and by conduit 251 to bore 261 of pad assembly 257 for application o vacuum pressure at the undersurface of vacuum pad 260.
Another internal passageway (also not illustrated) from bearing block 218 through mounting plate 246 is connected by fitting 266 to tubing 267 connected by nipple screw fitting 268 to upper chamber portion 252a to provide a continuous passageway for air pressure from a source (not shown) through the passageway of block 218 through mounting plate 246 into upper chamber portion 252a against the upper face of piston 251, thereby to cause piston rod 250 to extend from air cylinder 248. Another passageway, indicated at reference numeral 269, introduces air from a source through bearing block 218, mounting plate 246, and air cylinder 248, into lower chamber portion 252b against the lower face of piston 251, thereby to cause piston rod 250 to retract into air cylinder 248 to the extent permitted by stop 262.
In its lower extremity, bearing block 218 and mounting plate 242 have aligned air passageways that interconnect (sealed by O-rings 270a, 270b) to admit air through conduit 271 into horseshoe conduit 272 of socket opener 247, which is attached to the lower portion of mounting plate 246 by recessed machine screws (not shown).
Referring to FIG. 10 taken with FIG. 12, socket opener 247 is seen to be rectangular in shape with a central rectangular aperture 273 through which, in FIG. 12, the interior face of vacuum pad 260 and the vacuum passageway 261 are visible. Socket opener 247 includes an upper socket opener mount 274. Horseshoe conduit 272 resides in socket opener mount 274 and opens into four corner bores 275, 276, 277 and 278 which open to the bottom of mount 274. The two outer corner bores 277, 278 are illustrated in cross section in FIGS. 11 and 13. Fitted into bores 273-276 are four pistons, of which two pistons 279 and 280 are visible in FIGS. 11 and 13. The base of each piston is internally threaded to accept a screw. Screws 281, 282, 283 and 284 secure socket opener plate 285 to the bases of these pistons, including illustrated screws 283 and 284, respectively, to pistons 279 and 280. O-rings 286a-d seal the positive pressure imparted from horseshoe conduit 272 to the crown of these pistons within bores 275-278. Midway between the outer corner bores 277, 278 are coaxial first and second bores 287, 288. Midway between inner corner bores 275, 276 are coaxial first and second bores 289, 290. The coaxial second bores 288, 290 open to the bottom surface of socket opener mount 285; the coaxial first bores 287, 289 are of larger diameter and open to the top surface of socket opener mount 285. Coil springs 291, 292 fit respectively in bores 287, 289 under compression against the slotted heads 293a, 294a of retaining rods 293, 294, which contain springs 291, 292 within bores 287, 289. The lower extremities 293b, 294b of rods 293, 294 are of diameter to pass through second bores 288, 290, are axially bottom tapped and internally threaded, and are bottom fastened to socket opener plate 285 by screws 295, 296 passed through drilled holes in plate 285. With this structure, air pressure admitted into bores 275-278 forces the pistons in the bores downwardly in a Y-axis direction, extending socket plate 285 from socket opener mount 274 a Y-axis distance determined by the length of the lower extent of retaining rods 293, 294 and the height of second bores 288, 290. The downward extension further compresses coil springs 291, 292 between the slotted heads of rods 293, 294 and the base of first bores 287, 289. When air pressure on the pistons in the corner bores 275-278 is removed, energy stored in compressed springs 291, 292 is exerted against the heads of rods 293, 294, retracting plate 285 home to bear against the bottom surface of socket opener mount 274 under the force of the still partially compressed springs.
Although the plant head loader/unloader has been described for a particular embodiment in which the device holder is a vacuum head, other configurations may be employed for the device holder depending on the device to be loaded or unloaded from the particular kind of socket. The architecture of the plant head permits quick replacement of one kind of device holder with another.
Tube Transport System
IC devices are received from the device manufacturers in elongated plastic tubes of substantially rectangular cross section or in trays. As respects the tubes, conventionally the devices are placed in the tubes in a specific orientation so that the location of pin one is known when the device exits the tube. Referring to FIGS. 1, 4, 5, and 6 elongated tubes for IC devices are shown in outline and are indicated by reference numerals 1-8. Reference numerals 300A and 300B generally indicate dual tube transport systems for feeding device containing tubes to the dual device staging systems, indicated generally by reference numerals 400A and 400B.
A framework including lateral frame members 302, 303 and medial frame members 304, 305 extends from platform 24. Sheet metal panels cover the framework at the top, back, and medial sides. Referring to tube transport system 300A (like structure in tube transport 300B has one higher integer odd number, by the convention stated above). The panels include top panel 306, back panel 308 and medial side panel 310 (see especially FIGS. 1 and 3). Top panel 307, back panel 309 and medial side panel 311 of tube transport system SOOB are best viewed in FIG. 4. Slots 312, 313 are respectively provided at the X-axis midline of top panels 306, 307.
Mounted between lateral and medial frame members 302 and 304 of tube transport system 300A is an X-axis rodless air cylinder shaft 314. A magnetic dual acting air piston (not shown, but see comparable structure 439 in FIG. 8) is provided for X-axis movement in air cylinder 314. Air pressure tubing (not shown) passes air into one or the other of fittings (not shown) at the opposite extremities of rodless air cylinder shaft 314 according to air valving regulated by system controller 500. This air is impressed upon one of the two heads of the piston in fluid communication with the fitting to force the piston through the cylinder in a selected x-axis direction. Slidingly circumferentially mounted upon air cylinder shaft 314 is a magnetic slide block 316 of polarity opposite to the magnetic polarity of the piston within air cylinder shaft 314 (as maybe best viewed in FIGS. 3 and 4). Movement of the piston within air cylinder shaft 314 also moves sliding block 316 under the influence of the magnetic attraction between the piston and sliding block 316. Attached to sliding block 316 is drive plate 318 which medially has a Y-axis face perpendicular to the X-axis of air cylinder shaft 314. Thus, under the direction of the system controller valving air into air cylinder shaft 314, drive plate 318 is moved along the X-axis of air cylinder 314 according to system instruction. Mounted on top panel 306, below the bottom of drive plate 318, are a plurality of X-axis rails 320, 322 and 324. Fastened to top panel 306 by end mounts 326, 328 is end flange 330. Cover 332 is mounted above rail 324. An adjustable stop 334 is provided near the medial extremity of air cylinder shaft 314 to limit the medial X-axis extent of travel of slide block 316 and thereby limit the medial X-axis travel of drive plate 318.
In operation, a plurality of tubes containing IC devices are placed on the tube transport rails. For example, as in FIG. 1, for tube transport system 300A, the tubes are placed on rails 320, 322, 324 and flange 330. The system controller valves air into air cylinder 314 and forces the air piston in it toward frame member 304. The leading edge of drive plate 318 contacts the trailing edges of the device container tube most remote from device staging system 400A (for example, tube 8 in FIG. 1) and pushes it into Y-axis alignment parallel to the Y-axis medial face of drive plate 318 until all the tubes are aligned parallel to the Y-axis medial face of the drive plate, as illustrated for system 300B in FIGS. 1, 4, 5 and 6. When wafer switch 473 described below is closed, controller 500 is signaled and valves air to rodless cylinder 314 (315) to cease its medial movement towards frame member 304 (305).
Device Staging System
Referring to FIG. 1, device staging systems 400A and 400B are now described. As most advantageously viewed in FIG. 1, device staging systems 400A and 400B are disposed in a Y-axis, which is perpendicular to the X-axis of air cylinders 314, 315 of tube transport systems 300A and 300B, between which device staging systems 400A and 400B are positioned, and parallel to the Y-axis of ball screw shafts 210 and 211 of load/unload plant head systems 200A and 200B.
Referring to FIGS. 7 and 8 taken in conjunction with FIG. 4, device staging system 400B (like structure in device staging system 400A has one lower even number integer, by the convention stated above) is supported by U-shape bracket mount 70 affixed to the rear medial portion of platform 24. Mount 70 includes two arms 70a, 70b which project rearwardly from base plate 70c of mount 70. Affixed to the medial lower portions of the base 70c of mount 70 are female clevis flanges 401 which mount the front male clevis member 403 of piston rod 405 of siamesed air cylinder units 407, 409. Extending from siamesed unit 409 is piston rod 411 terminated in a male clevis 413, which pivotally attaches to female clevis member 415 by pivot pin 417. Female clevis member 415 depends from pivot block 419 which is laterally affixed to pivot plate 421. A main pivot pin 71 is journaled in support mount arms 70a and 70b. Pivot block 419 and affixed pivot plate 421 are supported on pivot pin 71 at bearings 423, 425.
Referring to FIGS. 7 and 8, front shuttle shaft mount 429 is affixed at the leading edge in an upper portion of pivot plate 421 and rear shuttle shaft mount 431 is affixed at the same elevation in the upper rear portion of plate 421. Supported by and between front and rear shuttle shaft mounts 429 and 431 are upper cylindrical support shaft 433 and lower cylindrical shuttle support shaft 435. Supported by mounts 429, 431 between support shafts 433 and 435 is rodless air cylinder 437. Inside rodless air cylinder 437, as illustrated in FIG. 8, is magnetic double acting air piston 439. Supported on support shafts 433 and 435 is magnetic slider block 441, which has opposite polarity to the magnetic poles of piston magnet 439. Fastened to the tops of support mounts 429, 431 and spanning the distance between them is cover panel 443.
Fastened to magnetic slider block 441 is shuttle plate 445, which has affixed to it medial flange supports 447, 449. Medial flange supports 447, 449 fixedly support air cylinders 451, 453. Air cylinders 451, 453 are horizontally disposed in the X-axis with their piston rods 455, 457, respectively, extendable laterally in an X-axis direction toward tube transport system 300B. Affixed to the tail of piston rods 455, 457 is the vertical member 459a of L-shaped tube carrier 459. The horizontal shelf member 459b of tube carrier 459 is horizontally level with rails 331, 321, 323 and 325 of tube transport system 300b, as best viewed in FIG. 4 (321 visible). Affixed at the top portion of vertical member 459a is a canopy member 461 which covers the central portion of tube carrier shelf 459b substantially between air cylinders 451 and 453. Surmounted on canopy 461 over apertures (not shown) are air cylinders 465, 467 that, when valved with air, extend adjustable shaft piston rods 469, 471 downwardly a predetermined extent calibrated to define a gap between the floor of shelf 459 and the end of pins 469, 471 equal to the height of device tubes 1-8. A wafer switch 473 is mounted in a normally open position on tube carrier vertical member 459a near the junction with tube carrier shelf member 459b. Receipt of a tube upon tube carrier shelf 459b flush against vertical member 459a depresses switch 473, closing it and signaling system controller 500, which valves air to air cylinders 465, 467 causing them to extend piston rods 469, 471 and engage tube 1 pressing tube 1 against shelf 459b.
Referring to FIGS. 5-8, shuttle plate 445 at its forward end mounts device slideway 475 with fasteners 477, 479 and 481. Slideway 475 comprises a center channel 483 and a rim of slightly higher elevation, 485. A slideway canopy 487 is provided over the rear and central portions of slideway 485. Slideway 485 contains internal separate vacuum passageways which individually communicate, respectively, with vacuum tubing fittings 489, 491, 493, 495, and 497. The internal passageways in device slideway 475 open into ports S 0 , S 1 , S 2 , S 3 and S 4 in the floor of channel 483 of device track 485. The ports are spaced apart a predetermined distance equal to center to center distances between touching devices as they are oriented longitudinally in tubes 1-8. The spacing between port S 0 and S 1 suitably is equal to the spacing between ports S 1 and S 2 multipled by the number of ports except port S 0 ; in this embodiment, the multiple therefore is four.
As it will have now been appreciated, the burn-in loader/unloader apparatus of this invention is comprised of two independent load/unload work stations. Each station comprises a burn-in board carrier system, a tube transport system, a load/unload pick and place plant head system, and a device staging system. Each station may operate independently using different device types or boards for maximum flexibility, or may be used jointly with the other station on a single device type and board to provide true continuous operation and maximize through-put. When used jointly, one carrier is positioned under the load heads, and the other is accessible to the operator for board or tray exchange.
For highest speed operation with joint use of the two independent stations, devices equal in number to the number of plant heads of each station can be loaded or unloaded to and from the burn-in board simultaneously by each station. In this parallel mode of operation, all load heads of a station insert or extract devices to or from the burn-in board at the same time. The alignment plates 222, 223 of the load/unload plant head system space the load heads 240 correctly to fit the columns or rows on the board. Alignment plates 222, 223 are attached to mounting blocks 212 by four quick detach screws. Mounting plate 242 for plant head assembly 240 is attached to mounting block 212 by two quick detach screws so a specific plant head assembly 240 for the particular socket 12 size and appropriate vacuum pad assembly 257 or other means at the end of rod 250 for releasably attaching an IC device can be quickly substituted. Slideway 475 is quickly exchangeable by fasteners 477, 479 and 481 for another slideway whose spacing for ports S 0 , S 1 , S 2 , S 3 and S 4 and channel width 483 is particular to another device size. All other spacing is controlled by data input through software as more particularly hereinafter described.
Alternatively, the two independent stations may be operated serially to load or unload a burn-in board. Serial operation eliminates the need to change an alignment plate to accurately space a station load heads to match the rows or columns on the burn-in board. The serial loading flexibility of the invention is particularly useful in reducing the risk of damage to burn-in boards by flex of the boards imposed in loading larger high insertion force devices more than one device at a time.
In the serial loading mode, the control system of the automated load/unload apparatus of this invention optimizes the load head path to the nearest socket, minimizing travel time between device insertions or extractions.
Control System
Referring to FIG. 18, a block diagram of the control system 500 is illustrated. In this portion of the description, the convention adopted hereinabove is not used; however, reference numerals employed in the block diagram refer to the same components as hereinabove described. At the heart of the control system 500 is microprocessor 501. The operator commands the microprocessor through keyboard input device 502 and push buttons on control panel 503. Messages are communicated to the operator from the microprocessor by monitor 504 and message lights on control panel 503. Programming instructions and stored data are furnished to microprocessor 501 from written media by read/write disc drive 505. Suitably, microprocessor 501, keyboard 502, monitor 504 and disc drive 505 are contained in a computer 510, shown in FIGS. 1 and 2.
Burn-in board socket spacing is entered manually from keyboard 502 or by leading a load head group from one corner socket of a burn-in board to a corner socket across the diagonal of the burn-in board. A learning routine of system controller 500 automatically calculates intermediate socket spacing using row by column information entered by the keyboard or from data storage for the particular burn-in board. The program routines are capable of identifying sockets on the burn-in board not to be loaded from data of socket locations where there ma be position failure.
Microprocessor 501 provides operating instructions to carrier drive motors 116, 117; to plant head group drive motors 224, 225; and to the air pressure cylinders employed in load/unload plant head systems 200A and 200B, in tube transport systems 300A and 300B, and in device staging systems 400A and 400B. In load/unload plant head systems 200A and 200B, this is to air cylinder 248 of each of plant head mounts 212, 213, 214, 215, 216, 217, 218 and 219. In tube transport systems 300A and 300B, this is to rodless tube drive cylinders 314 and 315. In device staging systems 400A and 400B, this is to tube load cylinders 451, 453 and 452 and 454; to tube capture cylinders 465, 467 and 466, 468; to shuttle plate rodless cylinders 437 and 438; and to device staging system pivot cylinders 407, 409 and 408, 410.
Microprocessor 501 also controls the vacuum applied to the plant heads for mounts 212, 213, 214, 215, 216, 217, 218 and 219 and to the ports S 0 , S 1 , S 2 , S 3 and S 4 of slideway 475.
Microprocessor 501 receives input from carrier position sensors 134, 136 and 138 for carrier system 100A and from 135, 137 and 139 for carrier system 100B; from plant head position sensors 232a, 232b and 234 of system 200A and from sensors 233a, 233b and 235 of system 200B; and also receives system inputs from vacuum sensors associated with the vacuum systems for each of ports S 0 , S 1 , S 2 , S 3 , and S 4 and for the vacuum lines 251, 261 of each plant head 244.
BIB Loading Operation from Tube
In the following description of loading a burn-in board, operation in the serial mode is described. In parallel operation, the individual plant heads of a plant head unit move as one when planting or extracting devices in sockets on the burn-in board.
In serial operation, operation of the dual stations of apparatus 10 is ideally 180 degrees out of phase (although it may vary from 0 degrees to 180 degrees out of phase), so that, for example, when station A is loading devices into a burn-in board on carrier 102, station B is operating to stage devices for pick-up. Accordingly, for simplicity, operation will be described in respect to one of the stations, station B.
In the operation of station B to load devices into the socket 11 of burn-in board 12, first, a tube containing the devices is loaded by tube transport station 300B onto device staging system 400B. Referring to FIG. 6, controller 500 valves air to the portion of air cylinder 437 remote from platform 24, driving piston 439 toward platform 24 thereby carrying with it slider block 441 to which shuttle 445 is fastened, thus extending device slideway 475 into its forward position over platform 24 and positioning tube carrier 459 into loading position. Controller 500 valves air pressure into air cylinders 451, 453 to extend piston rods 455, 457 from the cylinders, advancing tube carrier 459 to loading position when the piston rods are fully extended. Controller 500 then valves air pressure to the lateral fitting for air cylinder 315, thereby driving the piston contained in cylinder 314 medially toward device staging station 400b, slider block 317 moving with the piston and carrying with it drive plate 319, which forces tube 1 forward on guiderails 321, 323 and onto shelf 459b against upright 459a, in the process pressing wafer switch 473, which signals controller 500. Controller 500 valves air to air cylinders 465, 467, moving rod 469 down into contact with the top of tube 1, pressing it against shelf 459b, securing tube 1. Concurrently, controller 500 valves air to rodless tube drive air cylinder 315 to stop the advance of drive plate 319. Controller 500 then valves air to the top of the piston of air cylinders 451, 453, fully retracting piston rods 455, 457 and tube carrier 459. The controller then valves air to rodless shuttle air cylinder 437 to drive shuttle plate 445 away from platform 24 to its retracted position, shown in FIGS. 5 and 7.
With tube 1 loaded onto tube carrier 459, devices in the tube are then moved onto track 475 for pickup by load heads 213, 215, 217, and 219. Referring to FIG. 9, controller 500 valves air to cylinder 407, extending rod 405, which cranks female clevis 415 clockwise (as viewed in FIG. 9), rotating pivot block 419 affixed to pivot plate 425 about bearings 423, 425 on pivot pin 71 journaled in arms 70a, 70b, thereby pivoting pivot plate 421 device staging station 400B to a slideway down position in which the foreward portion of slideway 475 is lower than the rear portion of slideway 475, and slideway 475 is lower than tube carrier 459. The angle of "pivot down" inclination suitably is from about 25 degrees to about 32 degrees, preferably about 28 degrees. The elevation of the surface of shelf 459b is lower than the elevation of the center channel 483 of slideway 475 by a distance equal to the thickness of tube 1, so that the inner floor of the tube is at the same level as the floor of channel 483. Thus when device staging station 400B is rotated to the "pivot down" position illustrated in FIG. 9, devices contained in tube 1 slide from the tube onto and down channel 483 of slideway 475 through the tunnel defined by channel 483, rim 485 and canopy 487.
The slide of devices from tube 1 down slideway 475 is regulated by system controller 500 both to minimize any impact damage to the leads of the devices and to gate the devices into pickup position on the forward portion of slideway 475. The system controller regulates vacuum valving to ports S 0 , S 1 , S 2 , S 3 , and S 4 to turn vacuum pressure at the ports "ON" (vacuum on ) or "OFF" (vacuum off).
When the system controller "pivots down" device staging station 400B, it valves port S 0 OFF, and ports S 1 , S 2 , S 3 , and S 4 ON. The lead device sliding from tube 1 upon pivot down of device staging station 400B is braked and arrested to a stop over one of ports S 1 , S 2 , S 3 or S 4 by vacuum applied at ports S 1 , S 2 , S 3 and S 4 . System controller 500 then valves vacuum at port S 0 ON, and next valves vacuum at ports S 1 -S 4 OFF. This arrests the device over S 0 and all trailing devices in slideway, and permits all devices forward of port S 0 to slide down slideway 475 to any next unoccupied position, thus filling the positions over ports S 1 , S 2 , S 3 and S 4 (if there are a sufficient number of devices to do so). System controller 500 then valves ports S 1 -S 4 vacuum ON, and inspects to confirm vacuum at ports S 1 -S 4 .
If vacuum is not confirmed at all of the ports S 1 -S 4 (simplying one or more of the ports has no device in place over it for pickup), system controller 500 inspects port S 0 for vacuum. If vacuum exists at port S 0 (implying a device over port S 0 and perhaps a train of devices held behind it), the system controller valves vacuum to port S 0 OFF, permitting the device over port S and next trailing devices to slide down slideway 475 for arrest by vacuum still ON at ports S 1 -S 4 at a rear most port where a device is not already arrested. Turning port S 0 vacuum ON, system controller then valves ports S 1 -S 4 vacuum OFF, permitting the devices to advance forward to position over any unoccupied port. System controller 500 then valves vacuum ON to ports S 1 and S 4 and again inspects for vacuum confirmation at ports S 1 -S 4 . If vacuum is not confirmed at ports S 1 -S 4 , system controller 500 inspects for vacuum at port S 0 . If vacuum is again confirmed at port S 0 , yet after the foregoing gating of addition device(s) ports S 1 -S 4 are signaled still not wholly occupied, the implication is a jam is in the slideway; the system controller turns OFF the vacuum to ports S 0 and S 1 -S 4 , and, valving air from cylinders 407 and 409 to retract piston rods 405 and 411, respectively, cranks female clevis 415 counter-clockwise (as viewed in FIG. 9), rotating pivot block 419 affixed to pivot plate 421 about bearings 423, 425 on pivot pin 71 journaled in arms 70a, 70b, thereby rotating pivot plate 421 and device staging station 400B to the "pivot up" position illustrated in shadow outline in FIG. 9. This permits devices in slideway 475 to slide back towards and into the tube. System controller 500 then rotates the device staging unit 400B again to the pivot down position, turning ON vacuum to ports S 1 -S 4 , and repeats the device loading sequence explained above.
In the sequence explained above, when ports S 1 -S 4 are inspected for vacuum, are not all vacuum confirmed, and port S 0 is then inspected for vacuum, the routine was explained where port S 0 is vacuum confirmed. If port S 0 is not vacuum confirmed, it is assumed there are no devices left to load. System controller 500 checks for existence of a tube in place on shelf 459. If the inspection signifies a tube is in place, it is assumed to be an empty tube, system controller 500 "pivots up" device staging station 400B, valves OFF pressure to air cylinders 465, 467, thereby retracting rods 469, 471, releasing the tube for gravity fall into a catch receptacle (not shown). System controller 500 then cycles to the tube feed routine described above. If the tube check signifies no tube is in place, system controller 500 cycles directly to the tube feed routine.
The two next preceding paragraphs described subroutines entered when vacuum was not confirmed at ports S 1 , S 2 , S 3 , and S 4 . If vacuum is confirmed at ports S 1 , S 2 , S 3 , and S 4 , controller 500 then regulates air pressure to piston 413 to retract piston 405, rotating pivot plate 421 to a level position (in which the opposite ends of slideway 475 are at the same level). FIG. 9 illustrates the position in which devices are confirmed at ports S 1 , S 2 , S 3 , and S 4 and a stopped device is confirmed at port S 0 .
With the devices now positioned at the foreward portion of device slideway 475 held there a vacuum applied to ports S 1 , S 2 , S 3 and S 4 , system controller 500 regulates air pressure to rodless shuttle air cylinder 437 to drive piston 439 toward platform 24 and carry shuttle plate 445 to a position extending track 471 over a rear portion of platform 24. Controller 500 then applies pulses to loader/unloader drive motor 225 to rotate ball screw shaft 211 in ball nut 221 and thereby move connected blocks 213, 215, 217 and 219 along Y-axis shafts 207 and 209 to a start position in which the foremost load/unload head assembly 219 is situated over the foremost port S 4 of slideway 475. In the serial mode of operation, it is unnecessary for more than one plant load/unload head in the unit to be aligned over a specific port. The home position of the foremost head assembly and the given spacing between the successive ports of S 1 -S 4 defines the linear increment which must be driven by drive motor 225 shaft rotation to sequentially align the next selected plant head e.g., plant head 217, over a next selected port, e.g. port S 3 , and so forth.
With plant head 219 centered over port S 4 , controller 500 valves vacuum OFF to port S 4 , vacuum ON to the vacuum line connecting with passageway 251, 261 terminating at vacuum pad 260, and valves air pressure to chamber 252a of plant head cylinder 248, thereby extending rod 250 and attached vacuum pad 260 down into contact with the device over port S 4 , attaching that device. The system controller then valves air pressure through line 269 to chamber 252b of plant head air cylinder 248 to retract vacuum pad assembly 257 and lift the device that was at port S 4 from slideway 475. System controller 500 then sends impulses to drive motor 225 to cause rotation of ball screw shaft 211 to advance the plant head unit a predetermined increment to place the plant head unit corresponding to mount 217 over vacuum port S 3 , where the sequence described above for the foremost plant head for mount 219 is conducted, commencing with system controller 500 valving vacuum OFF to port S 3 , to pick up the device over port S 3 . After pickup of the device over port S 3 , controller 500 then advances the plant head unit another predetermined increment so that the plant head connected to mount 215 is over port S 2 , for pick up of the device over port S 2 the same as in the above and foregoing operation, but commencing with system controller 500 valving vacuum to port S 2 OFF. After the device over port S 2 is picked up by the head for mount 215, the plant head unit is advanced another increment and the head associated with mount 213 is positioned over port S 1 , vacuum to port S 1 is valved OFF, and the operation hereinabove described is conducted to pick up the device over port S 1 . At this point, with all devices picked up, controller 500 pulses drive motor 225 to move the plant head unit for system 200B a specific Y-axis distance along support shafts 207, 209 calculated to position foremost plant head 219 at a specific location. Controller 500 in the meantime has pulsed carrier drive motor 117 to rotate ball screw shaft 121 and drive ball nut 127 mounted to carrier plate 103 a specific X-axis distance along X-axis support shafts 60, 61 so that for the row/column spacing of sockets 11 on burn-in board 12, a specific socket is placed at an X-axis location under a predetermined Y-axis location that is the location to which the foremost head 219 of the plant head unit of 200B will be driven.
At the same time that plant head drive motor 225 drives the 200B plant head unit towards its position, controller 500 valves air to shuttle cylinder 437 to move air piston 439 rearwardly away from platform 24 and retract slideway 475 to its retracted position (FIG. 7). Device staging station 400B then again cycles through its device staging operation which terminates in extension of slideway 475 over platform 24 as hereinabove described.
With the plant head unit over the socket position determined by the system controller, the device held by vacuum pad 260 is then planted in that socket 11 on burn-in board 12. Referring to FIGS. 10-14C, system controller 500 valves air into horseshoe conduit 272 to drive the pistons in the corner bores 275-278 to the fully extended position permitted by latch rods 293, 294 thereby pushing socket lid opener 285 against socket lid 11a of socket 11 as illustrated in FIG. 14B, levering apart the spring biased socket contacts of socket 11 and allowing clearance for placement of the device held by vacuum pad 260. System controller 500 then operates to valve air to chamber 252a of air cylinder 248 to extend rod 250 a predetermined distance to place the device held by pad 260 preferably just at or above the upper surface of socket lid 11a. Controller 500 next valves OFF the vacuum to conduits 251, 261, releasing the device from pad 260 and permitting it to drop-settle into place between the spread contacts of socket base 11b. Dropping the device this short distance lets it self adjust to a centered position. With smaller devices such as the PLCC devices, controller 500 may valve additional air to chamber 252a of air cylinder 248 to extend the pad 260 into the still spread socket base and "step on" the device and hold it in place while controller 500 valves OFF the air pressure to horseshoe conduit 272, and springs 291, 292 acting respectively on guiderods 293 and 294 force guiderods 293, 294 upwardly in chambers 287, 289, thereby retracting socket lid opener 285 and permitting socket lid 11a to rise and press the spring loaded contacts within socket 11 onto the leads of the captured device, capturing the device in the socket. With the device securely sequestered within the socket, controller 500 then valves air to chamber 252b of cylinder 248, forcing piston 251 and rod 250 upwardly and withdrawing pad 260 from within the socket to its fully raised position. With larger devices such as SOIC or PQFP devices, there is less need to "step on" the device during release of the socket lid, and the step of further extending the pad 260 may be omitted. Drive motor 225 is then actuated to advance the plant head unit of 200A a predetermined increment to situate the plant head for mount 217 over the next socket 11 calculated to be filled by the computer, and the device planting cycle described above for the foremost plant head is implemented, and so forth, until all devices from the plant heads have been planted and all plant head piston rods are in a retracted position. The plant head unit is then returned to the "in" pickup position by the controller, which cycles the pick-up device routine as described above.
Unloading Operation
In the operation of station B to unload devices from the sockets 11 of burn-in board 12, first, emptied tubes for the devices are loaded by tube transport mechanism 300B onto device staging system 400B the same as in the loading operation described above. With the emptied tubes loaded onto tube shelf 459 (the first loaded tube hereinafter is also called tube 1), system controller 500 applies pulses to loader/unloader drive motor 225 to rotate ball screw shaft 211 and ball nut 221 and thereby move connected blocks 213, 215, 217 and 218 along Y-axis shafts 207 and 209 to a start position in which a selected one of the plant heads, for example the plant head associated with mount 219, is situated over a specific location along the X-axis of carrier 103. Controller 500 then pulses carrier drive motor 117 to rotate ball screw shaft 121 and drive ball nut 127 mounted to carrier plate 103 a specific X-axis distance along X-axis support shafts 60, 61 so that for the row column spacing of sockets 11 on burn-in board 12, a specific socket is placed under the Y-axis position of plant head 219. With the selected plant head over the socket position determined by the controller 500, the plant head is operated to pick up the device from the socket. Referring to FIGS. 10-14C, controller 500 valves air into horseshoe conduit 272 to drive the pistons in the corner bores 275-278 to the fully extended position permitted by latch rods 293, 294 thereby pushing socket lid opener 285 against socket lid 11a of socket 11 as illustrated in FIG. 14B. This levers apart the socket spring biased contacts, freeing the device in socket 11 from the grasp imposed by the contacts. Controller 500 then valves vacuum to vacuum lines 251 and 261, and valves air pressure to chamber 252a of air cylinder 248 to extend rod 250 a predetermined distance to place vacuum pad 260 on the device resting free in the socket base 11, capturing the device with the vacuum applied at pad 260. Controller 500 next valves air to chamber 252b of air cylinder 248 to retract rod 250 and remove the device from socket 11. Controller 500 next conducts a inspection routine to inspect that the device is attached by confirming vacuum (and if absence of vacuum is determined, repeats the routine to apply vacuum to the plant head, depress the socket lid, extend the piston rod with vacuum pad into the socket, attach the device, and retract the rod, after which it again inspects for device attachment, and if not then detected, sounds a sonic alarm). Upon confirmation of vacuum, the microprocessor then valves OFF the air pressure to horseshoe conduit 272 so that springs 291 and 292 force guiderods 293 and 294 upwardly in chambers 287 and 289, retracting socket lid opener 285, and permitting socket lid 11 to close. Controller 500 then actuates drive motor 225 to advance the plant head unit a predetermined increment to situate another of the plant heads over another socket, whose location is calculated by the controller 500, and the device unloading cycle described above for the foremost unit is conducted, and so forth, until all the plant head have picked up devices from sockets for which they are targeted. Controller 500 then pulses plant head drive motor 225 to drive the plant head group unit of 200B to an unloading position where controller 500 has positioned slideway 475 by valving air to rodless air cylinder 437 to extend slideway 475 to its forward position. Controller 500 then valves ON vacuum to ports S 0 , S 1 , S 3 , and S 4 . Controller 500 next valves air pressure to a selected one of the plant heads, for example, the plant head associated with bearing block 219, and thereby extends piston rod 250 and lowers vacuum pad 260 containing the attached device until it is immediately over a selected vacuum port, for example, S 4 . Controller 500 then valves cap OFF vacuum to lines 251 and 261 to vacuum pad 260, releasing the device to port S 4 , where it is vacuum captured and held at port S 4 . Controller 500 then directs air pressure to chamber 252b to cause retraction of plant head rod 250. Next controller 500 pulses plant head drive motor 225 a predetermined increment to situate a next selected plant head over a next selected vacuum port on slideway 475 and repeats the foregoing cycle to deposit the device held by the vacuum pad of that plant head, and so forth, until all device are loaded on all of the ports S 1 , S 2 , S 3 , and S 4 . At this point, controller 500 pulses plant head drive motor 225 to drive the plant head unit to a next calculated position over carrier 103 to resume the unload routine, and valves air to rodless cylinder 437 to retract shuttle plate 445 and slideway 475. Controller 500 the valves air to air cylinders 407 and 409 to retract rods 405, 411 and cause pivot plate 421 and device staging system 400B to "pivot up" (tube down), at the same time turning OFF the vacuum to ports S 1 , S 2 , S 3 and S 4 , releasing the devices from the slideway ports and permitting them to slide down the inclined slideway into the tube held by tube loader shelf 459. A preferred "pivot up" angle is about 30 degrees. Controller 500 then directs air to air cylinder 409 to pivot plate 421 and device staging system 400B to a level position, and next applies air to shuttle rodless air cylinder 437 to extend slideway 475 for receipt of devices unloaded by the plant head units that have been retrieving more devices while devices unloaded in the prior cycle were being loaded into a tube.
BIB Loading/Unloading from Tray
Some IC devices are packed by the manufacturer in trays instead of tubes. In trays the devices usually are placed in recesses arranged in a specific pin one orientation in a grid of rows and columns with protective packaging to prevent shifting. The apparatus of this invention may be used to load and unload burn-in boards from trays as well as tubes. The tray to be unloaded is placed on a holder plate (not shown) which is accepted by guide rails 145, 147 (for example). The holder plate secures the tray in fixed position with pin one orientation as desired. Tray row-column spacing information is input by computer keyboard 502. System controller 500 controls drive motor 116 to move carrier plate 102 to its left most position and parks it. Controller 500 then pulses drive motor 117 to move carrier 103 to the left, moving the tray captured between guide rails 145, 147 to beneath station 200B. System controller 500 pulses drive motor 225 to move a selected plant head 244, for example, the one attached to block mount 213, to position over a device on the tray. Controller 500 valves air to chamber 252a of air cylinder 248, thereby extending rod 250 and attached vacuum pad 260 down into contact with the device in the tray, attaching that device. The system controller then valves air pressure through line 269 to chamber 252b of plant head air cylinder 248 to retract vacuum pad assembly 257 and lift the device from the tray. System controller 500 then sends impulses to drive motor 225 to cause rotation of ball screw shaft 211 to advance the plant head unit a predetermined increment to place the plant head unit corresponding to mount 215 over the next adjacent device in the tray, where the sequence described above for the foremost plant head for mount 213 is conducted. After pickup of the next device in the tray, controller 500 then advances the plant head unit another predetermined increment so that the plant head connected to mount 217 is the second next device in the tray, for pick up of that device the same as in the above and foregoing operation. After the second next device in the tray is picked up by the head for mount 215, the plant head unit is advanced another increment and the head associated with mount 219 is positioned over the third next device in the tray, and the operation hereinabove described is conducted to pick up the third next device in the tray. At this point, with four devices picked up, controller 500 pulses drive motor 117 to move the carrier plate 103 to the right a specific X-axis distance along support shafts 60, 61 calculated to position the burn-in board 12 between guide rails 143, 145 at a specific location under the plant head unit of system 200B. With the plant head unit over the desired row/column of burn-in board 12, the devices are planted in the row/column sockets of burn-in board 12 as described above. The carrier 103 is then moved to position another group of devices on the tray, under the plant heads, and if necessary because of the location on the tray of the next group of devices to be removed from the tray, plant head unit 200B is moved on its Y-axis, and the tray unloading step is performed again, and so forth, until the tray is unloaded and the burn-in board is filled. Unloading of burn-in board 12 and loading to the tray is the reverse operation of unloading the tray and loading the burn-in board.
Having now detailed my invention in both its apparatus and process aspects, those skilled in the arts will appreciate various modifications of my invention, and those modifications, though not described in the detailed embodiment set forth above, are covered if within the spirit and scope of my invention.
|
A printed circuit board loader and unloader in which a printed circuit board carrier is horizontally translationally moved in a straight line along a first axis and a pick and place head unit is horizontally translationally moved above the carrier in a straight horizontal line along a second axis perpendicular to the first axis. A device stager holds a tube containing integrated circuit devices fed to it by a tube transporter. In a straight path from the opening of the tube facing the carrier is a slideway operatively connected with the tube holder. The slideway has gating and device fixing vacuum ports. The device stager is pivotable to (i) a pivot down position to slide devices from the tube onto the slideway and vacuum arrest and gate them, (ii) a pivot level position in which the devices are picked up from over the forward ports on the slideway, and (iii) a pivot up position which devices slide from the forward portion of the slideway into a tube in the tube holder of the device stager. The pick and place system loads the printed circuit board by vertically picking up devices from the level slideway, traveling horizontally to a pre-calculated position, and placing the devices in sockets on the printed circuit board on the carrier positioned at that calculated position, employing in one aspect a special zero insertion force socket opener. The pick and place system unloads the board by vertically extracting the devices from the precisely positioned board, horizontally moving them to the slideway, and vertically depositing the devices on the level slideway, which then pivots up to deposit them in a tube being loaded.
| 8
|
BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to farm tractors and to a device to allow easy connection and alignment of a tractor drawbar with the pulled implement and for automatic latching of the drawbar in pulling position after connection.
Current agricultural implements, and especially wagons when loaded, are very heavy and are virtually impossible to move without power. Engagement of that power--usually a farm tractor--with the wagon or other implement is usually effected by use of a simple hitch pin running through the drawbar of the tractor and a clevis type tongue on the wagon. Thus, fairly accurate alignment of the holes in the drawbar and in the clevis is necessary.
Many wagon tongues are extensible so that some longitudinal adjustment of the tongue is possible to obtain the necessary alignment. However, lateral movement is ordinarily obtainable only by swinging the tongue to the side, thereby turning the wheels of the wagon. When fully loaded, such movement is very difficult especially with the larger wagons.
Drawbars on many tractors can be swung from side to side to provide the necessary lateral movement, but a free swinging drawbar creates difficulty while pulling the wagon in that the pivot point between the tongue and the tractor then becomes a location under the tractor instead of to the rear of the tractor. The result is that in turning corners, the wagon may trail in a position to interfere with the rear wheels of the tractor. The solution to that problem is to lock the drawbar in a straight rearward position while pulling a wagon so that the pivot point is to the rear of the tractor.
My device allows both a swinging movement of the drawbar laterally and a locked position. The device is readily controllable so that the drawbar can be released to swing and then set so that the drawbar will be latched in pulling position at the first instance when the drawbar swings past that position.
FIGURES
FIG. 1 is a top plan view of my device apart from the tractor and showing the tabs in the upright or pulling position,
FIG. 2 is a rear elevational view of the device as shown in FIG. 1,
FIG. 3 is a view similar to FIG. 2 of the device with the tabs in the lowered or released position and also showing the controls,
FIG. 4 is an end elevational view of the device in the position shown in FIG. 2, and
FIG. 5 is a view similar to FIG. 4 with the device in the position shown in FIG. 3.
DESCRIPTION
Briefly my device is adapted to be attached to a farm tractor near the drawbar and includes a pair of tabs normally embracing the crossbar in a pulling position. Controls are provided to allow either or both of the tabs to be depressed to allow the crossbar to swing and then to snap into upright position to lock the bar as proper alignment is reached.
More specifically, I mount my device on a cross member 10 having holes 11 allowing the device to be attached to the tractor. Bearing holders 12 are affixed to the cross member 10 and are designed to receive a shaft 13 which carries the tabs 14 journalled thereon. Thus, the shaft 13 is able to turn within the bearings at the holders 12, and the tabs 14 can also be rotated on the shaft.
In order to control the position of the tabs 14 on the shaft 13, I provide for pins 15 on the shaft and corresponding pins 16 on the tabs. A double coil spring 18 engaged between spring holding pins 19 on the tabs 14 and a holding pin 20 on the shaft 13 is arranged to press the pins 15 and 16 into normal engagement.
However, either tab 14 can be rotated on the shaft 13 against the urging 25 of the spring 18 so that the pins 15 and 16 become disengaged.
The rotative position of the tabs 14 relative to the tractor is controlled by the position of the shaft 13 unless some means forces the tabs 14 to rotate against the spring 18. The position of the shaft, in turn, is controlled by a However, either tab 14 can be rotated on the shaft 13 against the urging of the spring 18 so that the pins 15 and 16 become disengaged.
The rotative position of the tabs 14 relative to the tractor is controlled by the position of the shaft 13 unless some means forces the tabs 14 to rotate against the spring 18. The position of the shaft, in turn, is controlled by a control means operated from the seat of the tractor. This means includes an arm 22 attached to the shaft 13. A link 23 connects the arm 22 to a bell crank mechanism 24. The crank 24 is pivotally mounted on a bracket 25 which may be variously formed to be attached to various types and makes of tractor in a location well above the drawbar. On a tractor without a cab, this location may be within reach of the operator on the seat. On tractors with a cab, the arm extends upward to a point some four feet above the drawbar where an operator can readily reach it while hooking up the wagon.
In normal position, as shown in FIG. 4, the control arm 26 is in an upright position. The tabs 14 are then in a vertical position adapted to embrace the tractor drawbar 27 (FIG. 2). This is the pulling position in which the drawbar is constrained in a longitudinal location to provide the rearward pivot point for the implement tongue. However, the crank 24 can be turned by depressing the arm 26 to the position shown in FIG. 5. This pulls the arm 22 upward, rotating the shaft 13 and causes the tabs 14 to be turned to a position nearly horizontal. I prefer to proportion the parts of the bell crank 24 and the arm 22 so that the crank goes past center (FIG. 5) when the tabs 14 are fully depressed. The result is that the tabs will retain the depressed position without further manual control.
The depressed position of the tabs 14 removes them from the path of a swinging drawbar 27 so that it can be moved laterally--to the position shown at 27' in FIG. 3 for example. Thus, when the tractor is backed up to be hitched to a wagon, some lateral misalignment can be accommodated by being able to move the drawbar laterally. If the implement tongue is longitudinally adjustable, as most are now, the lateral movement of the drawbar combined with the longitudinal movement of the tongue makes it easy to align the holes in the tongue with that in the drawbar for insertion of the hitch pin.
After the hitch pin is inserted and if the drawbar is not directly on its longitudinal track, it is necessary to achieve that configuration. Release of and raising of the control arm 26 to its normal position (FIG.4 ) will raise the tabs 14 to a vertical position. However, if the drawbar 27 is displaced laterally, it will interfere with the raising of one tab on the side to which it is displaced. This interference simply disengages the pin 16 from pin 15 against the spring 18 and holds the tab 14 springably against the underside of the drawbar. The tractor can then be pulled forward and steered so that the drawbar comes into proper pulling alignment. At that point the tab 14 which had been depressed will be freed to snap upward under influence of the spring 18 and the drawbar will once again be constrained from lateral movement.
In order to allow reasonable proportions of the bearing holders 12 it may be necessary to extend the tabs 14 laterally to cover those holders. I do this simply by welding sloping membrs 29 to the tabs 14. However, it will be obvious that the tab could be formed intially to extend over the holder 12, or that other shapes could be used so long as the feature of having the displaced drawbar 27 hold the tab 14 in a depressed position and allowing it to spring back when aligned is retained.
|
A device for connection to a farm tractor to allow controlled movement of a drawbar including spring loaded side tabs controlled to provide for holding the tabs out of the path of the drawbar but releasable to a position to latch the drawbar in pulling position. The tabs are formed to provide for allowing the drawbar to slide into the latched position.
| 1
|
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates generally to erosion control devices, and more particularly to a sediment control wattle including a durable synthetic sheath containing a polymeric fill material.
[0003] 2. Background
[0004] The prior art includes a variety of assemblies directed towards reducing the effects of soil erosion. Straw and excelsior wattles, logs and rolls, in common use, are configured as elongated tubes of compacted straw or excelsior encased in flexible netting material. See www.earth-savers.com for general descriptions and specifications of wattles. Wattles are installed along contours or at the base of slopes to reduce soil erosion and retain sediment. Straw and excelsior wattles, logs and rolls have been state-of-the-art in erosion and sediment control for many years, and are considered best management practice or BMP in current Clean Water Act regulations and guidelines. Yet, the rice straw wattle testing and properties table claims only 58% minimum soil loss effectiveness for a 9-inch wattle.
[0005] Additionally, the prior art includes U.S. Pat. No. 6,855,650 to Bohannon, Jr., entitled Synthetic Fiber Filled Erosion Control Blanket, discloses a resilient erosion control blanket including a recycled filler including polyethyleneterephthalate in the form of recycled soda bottles which has been converted into a crimped, highly resilient fibrous filler contained within an open-meshed material of natural or synthetic fibers.
[0006] U.S. Pat. Nos. 6,641,335 and 6,527,477 to Allard, entitled Erosion Control Rolls, discloses an erosion control device including a walled elongated core member is disclosed having a first open end, a second end, an interior space and one or more openings in the wall communicating the interior space with the exterior of the core member. An outer filter member surrounds the core member. One or both the first and second ends of the core member can be open. One or both of the open ends can comprise couplers or connectors for connecting one core member to one or two complimentary core members. The core member may comprise a flexible plastic pipe, such as high-density polyethylene pipe having a plurality of perforations.
[0007] U.S. Pat. No. 5,786,281 to Prunty, et al., entitled Erosion Control Blanket and Method of Manufacture, discloses an environmentally sound vegetation growth-enhancing erosion control blanket formed from an elongated rectangular excelsior/wood wool mat. The mat is held together with adhesive and a surface pattern is embossed therein. As ground vegetation grows, it ultimately replaces the blanket which decomposes providing nutritive mulch.
[0008] U.S. Pat. No. 5,678,954 to Bestmann, entitled Ecological Coir Roll Element and Shoreline Protected Thereby, discloses a generally cylindrical fiber roll consisting essentially of coir material with a netting material about the exterior surface of the roll.
[0009] U.S. Pat. No. 5,651,641 to Stephens, et al., entitled Geosynthetics, discloses a mat formed of scrim which is tufted with a number of tufted ends in order to provide high tensile strength, greatly porous and flexible mats contain a number of interstices for capturing root systems, retaining soil, and controlling the flow of water.
[0010] U.S. Pat. No. 5,519,985 to Dyck et al., entitled Machine for Producing Straw-Filled Tubes of Flexible Netting Material discloses an apparatus and method of filling tubes of flexible, large mesh, netting material with compacted rice straw, or the like. The finished straw tubes are on the order of nine inches in diameter, twenty five feet in length and thirty pounds in weight; and lend themselves to use in controlling or mitigating the effects of erosion and to promoting revegetation.
[0011] U.S. Pat. No. 5,405,217 to Dias, et al., entitled Device for Erosion Control, discloses an elongated tubular assembly including a plurality of tubular units disposed in end-to-end relationship, each unit including a lower section composed of a variably rigid impermeable contact base and an upper section with a variably rigid protruding hull. The lower and upper parts are connected to each other to provide an internal space into which ballast can be admitted.
[0012] U.S. Pat. Nos. 5,330,828 and 5,484,501 to Jacobsen, Jr., et al., entitled Wood Fiber Mat for Soil Applications, discloses a wood fiber mat comprised of a mixture of thermo-mechanically processed wood and synthetic fibers.
[0013] U.S. Pat. Nos. 5,249,893 and 5,358,356 to Romanek et al., entitled Erosion Control Mat, discloses an erosion control mat formed as a composite fabric including a scrim formed of polypropylene, polyester, nylon, rayon, polyethylene, cotton, or combinations thereof, and uniform lightweight web secured to the scrim.
[0014] U.S. Pat. No. 5,207,020 to Aslam, Jr., et al., entitled Biodegradable Slit and Expanded Erosion Control Cover, discloses an erosion control blanket made of recycled, biodegradable slit and expanded sheets of paper.
[0015] U.S. Pat. No. 4,635,576 to Bowers, entitled Stitched Woodwool Mat, discloses a soil erosion control blanket formed from a mat of interlocking woodwool fibers, the mat of woodwool being retained as a coherent structure by means of longitudinal rows of stitching.
[0016] U.S. Pat. No. 4,592,675 to Scales, et al., entitled Revetment Panel with Staggered Compartments discloses a revetment panel including a fabric web having a plurality of compartments that are staggered in relation to each other and separated by selvage. The web is formed of two fabric layers, which are woven separately to form the compartments and fastened together to form selvage separating them. The web is transported to its installation site and placed. The compartments in the web are then inflated with the filler material, which may be cementitous slurry or mortar.
[0017] U.S. Pat. No. 4,342,807 to Rasen, et al., entitled Low Density Matting and Process, discloses a matting consisting essentially of melt-spun thermoplastic macrofilaments which are self-bonded or fused at random points of intersection without using any bonding agent or reinforcing inserts.
[0018] U.S. Pat. No. 4,353,946 to Bowers, entitled Erosion Control Means, discloses an erosion control blanket formed from wood wool fibers retained in a coherent structure with a biodegradable mesh.
[0019] U.S. Pat. No. 3,517,514 to Visser, entitled Soil Protection Mats discloses mats of non-woven fabric having randomly oriented polypropylene fibers.
[0020] While the prior art provides any of a number of devices aimed at controlling or reducing the effects of soil erosion, it appears that few if any of the disclosed devices or systems provide a very effective means for reducing flow beneath the device or a means for joining two or more wattles, or other erosion control devices together to reduce flow or migration of sediment between the individual devices. Additionally, many of the previously disclosed devices are constructed of materials that are relatively absorbent and therefore are not prone to removal and reinstallation. Additionally, increased weight and volume contribute to increased cost of transportation and handling.
[0021] Therefore, advantage may be found in providing a relatively lightweight sediment control wattle, constructed of a durable fabric having a lightweight fill that is relatively non-absorbent. Additionally, advantage may be found in providing a sediment control wattle that is constructed in such a manner that permits adjacent wattles to be joined to form an erosion and sediment control system in a manner that reduces migration and flow of fluid and sediment between wattles. Additionally, advantage may be found in providing a sediment control wattle that is constructed in such a manner that provides a means for securing the sediment control wattles to a hillside or slope in a manner that reduces migration and flow of fluid and sediment underneath the wattles. Further advantage may be found in reduced excavation required for installation and reduced labor and cost for transportation, handling and installation of a small lightweight sediment control wattle. Additionally, advantage and savings may be found in the ability to re-use the sediment control wattle from project to project over a period of several years.
[0022] Therefore, an objective of the present invention is providing a relatively lightweight sediment control wattle, constructed of a durable fabric having a lightweight fill that is relatively non-absorbent. An additional objective of the present invention is providing a sediment control wattle that is constructed in such a manner that provides a means for securing the sediment control wattle to a hillside or slope in a manner that reduces migration and flow of fluid and sediment underneath the wattles. Additionally, an objective of the present invention is providing a sediment control wattle that is constructed in such a manner that permits adjacent wattles to be joined to form a sediment control system in a manner that reduces migration and flow of fluid and sediment between wattles. A further objective of the present invention is providing small lightweight sediment control wattles that allow reduced excavation for installation and reduced labor and cost for transportation, handling and installation of the wattles. Additionally, an objective of the present invention is providing a durable sediment control wattle capable of being re-used from project to project over a period of several years.
SUMMARY OF THE INVENTION
[0023] The present invention is directed to an sediment control wattle comprising a sheath formed of a geotextile, the sheath containing a filler media. The sheath includes an apron constructed along a length of the sheath, extending from the sheath. The apron provides an element that may be pinned or otherwise attached to a terrain in a manner that reduces migration and flow of fluid and sediment underneath the wattles. In a preferred embodiment, the sediment control wattle also includes a joint wrap, which permits adjacent wattles to be joined, in an end to end configuration, to form a sediment control system in a manner that reduces migration and flow of fluid and sediment between wattles.
[0024] The present invention is also directed to a relatively lightweight sediment control wattle, constructed of a geotextile fabric having a lightweight fill that is relatively non-absorbent. In addition, the invention is directed to a sediment control system including a plurality of sediment control wattles constructed according to the teaching of the present invention, the plurality of sediment control wattles being connected at adjacent ends.
[0025] Additional advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. Additionally, the advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 is a representative perspective view of a sediment control wattle according to the present invention;
[0027] FIG. 2 is a representative perspective view of a sediment control system including a plurality of joined sediment control wattles according to the present invention;
[0028] FIG. 3 is a representative top view of a sediment control wattle according to the present invention;
[0029] FIG. 4 is a representative cross sectional view of a sediment control wattle wrap according to the present invention;
[0030] FIG. 5 is a representative cross sectional view of a sediment control wattle mid-section according to the present invention;
[0031] FIG. 6 is a representative cross sectional view of a sediment control wattle end stitching according to the present invention;
[0032] FIG. 7 is a representative cross sectional view of a sediment control wattle end tie according to the present invention;
[0033] FIG. 8 is a representative top view of a sediment control wattle system according to the present invention;
[0034] FIG. 9 is a representative cross sectional view of the two joined sediment wattles at the joint wrap in an installed condition, according to the present invention;
[0035] FIG. 10 is a representative top view of a sediment control wattle according to an alternate embodiment of the of the present invention;
[0036] FIG. 11 is a representative cross sectional view of a sediment control wattle according to an alternate embodiment of the present invention; and
[0037] FIG. 12 is a representative cross sectional view of a sediment control wattle according to an alternate embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Referring to FIGS. 1 and 3 , sediment control wattle 10 is shown including sheath 11 formed of a geotextile fabric. Sediment control wattle 10 also includes apron 12 and joint wrap 14 . In the preferred embodiment, sheath 11 is configured as a tubular sheath formed by rolling first edge 18 back towards second edge 19 and sewing longitudinal seam 15 along a length of the geotextile fabric. Longitudinal seam 15 is positioned along line L located between first edge 18 and second edge 19 resulting in the formation of tubular sheath 11 and apron 12 . In the preferred embodiment, end stitching 16 , located at first end 21 , and a self-locking cable tie 17 , located at second end 22 , are used to contain a filler media inside sheath 11 . Generally speaking, a geotextile is a fabric or textile that is designed to work in conjunction with a geological environment to enhance a particular environmental or geological objective, for instance soil erosion control or containment of soils. A geotextile may be woven or non-woven, formulated of natural or synthetic materials. A geotextile may be constructed of a rot-proof and/or ultra violet resistant material or, in the alternative the geotextile may be constructed of a material that is biodegradable. A geotextile may be impermeable or permeable to water and often the rate of permeability is a controlled feature of the construction of a geotextile. A geotextile may be made from staple or continuous filaments. Synthetic materials, including for instance, polypropylene, nylon and polyester and natural fibers including hemp, ramie, and jute provide satisfactory materials from which geotextiles may be fabricated. A permeable geotextile appropriate for the present invention may range in weight from 65 g/m 2 , (or approximately 2 ounces per square yard), to 700 g/m 2 , (or approximately 21 ounces per square yard). Permeable woven and non-woven geotextiles are characterized by relatively uniform, distinct and measurable percentages of open area. This assures that both water and soil particles up to a maximum size will have passage through the geotextile. Permeable woven and non-woven fabrics having relatively little open area, often trap soil particles within the fabric, clogging the geotextile.
[0039] Referring to FIG. 2 , a sediment control system 50 is shown including a plurality of sediment control wattles 10 A and 10 B, including sheath 11 A and 11 B, apron 12 A and 12 B and joint wrap 14 A and 14 B respectively. Sheath 11 A and sheath 11 B are each configured as tubular segments formed by sewing longitudinal seam 15 A and longitudinal seam 15 b respectively. As shown, sediment control wattles 10 A and 10 B include sheath 11 A and 11 B, apron 12 A and 12 B and joint wrap 14 A and 14 B respectively. Aprons 12 A and 12 B are construed to extend laterally from sheath 11 A and 11 B respectively. Sheath 11 A includes first and second ends 21 A and 22 A formed by end stitching 16 A and self-locking cable tie 17 A respectively. Similarly, sheath 11 B includes first and second ends 21 B and 22 B formed by end stitching 16 B and self-locking cable tie 17 B respectively. As shown, second end 22 A of sediment control wattle 10 A is placed adjacent to first end 21 B of sediment control wattle 10 B and inside joint wrap 14 B with an axis A of sediment control wattle 10 A and 10 B lying substantially in line. Apron 12 A is laid directly over apron 12 B at the joint wrap when installing 10 A and 10 B end to end.
[0040] FIG. 4 is a section taken through joint wrap 14 of sediment control wattle 10 shown in FIG. 3 , wherein sheath 11 and apron 12 are left un-sewn to form joint wrap 14 . End stitching 16 can be seen at the inside of joint wrap 14 .
[0041] FIG. 5 is a section taken through a mid-section of sediment control wattle 10 shown in FIG. 3 . Sediment control wattle 10 includes sheath 11 configured as a tubular segment formed by rolling first edge 18 back towards second edge 19 of apron 12 and sewing longitudinal seam 15 . Sheath 11 is shown filled with filler media 20 . In a preferred embodiment, filler media 20 includes a plurality of irregular globules formed of foam polystyrene, for instance Styrofoam® “peanuts”. Alternately, filler media 20 may comprise any of a variety of shapes including substantially spherical shapes, solid polygons or irregular solids. Preferably, erosion control baffle 10 may include any natural or synthetic fill having an absorption capacity under 2.0% by volume. Additionally, the preferred filler media exhibits a dimensional stability with under 10% linear change. Additionally, the preferred filler media exhibits a minimum compressive strength of 138 g/cm 2 or approximately 5 lb/in 2 .
[0042] Referring to FIG. 6 , sediment control wattle 10 including apron 12 , constructed according to the preferred embodiment of the present invention, is shown in cross section at end stitching 16 , which forms a closure at first end 21 of sheath 11 , as seen in FIGS. 1 and 3 . Preferably, end stitching 16 is oriented vertically to provide a vertical section having a height H that is at least equal to a diameter D of wattle 10 . As seen in FIG. 6 , longitudinal seam 15 is located with respect to end stitching 16 such that leg 25 is formed. Leg 25 assists in maintaining a generally vertical orientation of end stitching 16 when wattle 10 is in use. This construction results in a configuration that tends to eliminate slump between wattles 10 A and 10 B of sediment control system 50 at joint wrap 14 B, as shown in FIG. 2 .
[0043] Referring to FIG. 7 , sediment control wattle 10 , constructed according to the preferred embodiment of the present invention, is shown in cross section at the self-locking cable tie 17 , which is used to contain filler media 20 after the sheath 11 is filled with filler media 20 as shown in FIG. 5 . To attach self-locking cable tie 17 , a pointed end of the plastic cable tie is pushed through the apron 12 and wrapped around the gathered sheath 11 . The pointed end of the cable tie is then threaded through the cable tie self locking mechanism and pulled tight. It will be noted that self-locking cable tie 17 may be removed and replaced as desired to either add or remove filler media as desired.
[0044] Referring to FIG. 8 , sediment control wattles 10 A and 10 B are shown laid out end to end for installation along their respective axes represented by the reference character A As shown, sediment control wattles 10 A and 10 B include sheath 11 A and 11 B, apron 12 A and 12 B and joint wrap 14 A and 14 B respectively. Aprons 12 A and 12 B are construed to extend laterally from sheath 11 A and 11 B respectively. Sheath 11 A includes first and second ends formed by end stitching 16 A and self-locking cable tie 17 A. Similarly, sheath 11 B includes first and second ends formed by end stitching 16 B and self-locking cable tie 17 B. As shown, second end of sediment control wattle 10 A is placed adjacent to first end of sediment control wattle 10 B and inside joint wrap 14 B with an axis A of sediment control wattle 10 A and 10 B lying substantially in line. Apron 12 A is laid directly over apron 12 B at the joint wrap when installing 10 A and 10 B end to end.
[0045] Referring to FIG. 9 , installation of sediment control wattle 10 A inside, and 10 B, outside, are shown in cross section installed on terrain T. Sediment control wattles 10 A and 10 B are positioned in a cut C made substantially perpendicular to a slope, shown generally by vector SL, of terrain T. Aprons 12 A and 12 B are pinned to terrain T employing a plurality of pins shown generally as pin P 1 . Joint wrap 14 B is shown wrapped about a circumference of sheath 11 A of sediment control wattle 10 A and pinned to terrain T by pin P 2 . Fill F is then placed over aprons 12 A and 12 B.
[0046] Sediment control system 50 provides a sediment control device which minimizes migration of soils from an upper side of joined sediment control wattles 10 A and 10 B to a lower or downhill side of sediment control system 50 as aprons 12 A and 12 B are pinned and fill F is placed over aprons 12 A and 12 B thereby providing that a flow along slope SL of water and sediment would be against rather than underneath sediment control wattles 10 A and 10 B. Additionally, sediment control system 50 , as shown in FIGS. 2 and 8 , provides a means for combining a plurality of adjacent sediment control wattles in an end-to-end arrangement that eliminates migration of soils between adjacent sediment control wattles, as each pair of adjacent sediment control wattles 10 A and 10 B in FIGS. 2 and 10 A and 10 B in FIG. 8 , are coupled by a joint wrap, in this case 14 B.
[0047] Referring to FIG. 10 , an alternate configuration for a sediment control wattle 100 including apron 112 and joint wrap 114 is shown. Sheath 111 is shown closed at first end 121 by stitching 116 and self-locking cable tie 117 located at second end 122 . In this alternate embodiment, joint wrap 114 is configured as a panel that extends to sheath 111 and apron 112 of sediment control wattle 100 . Joint wrap 114 may be wrapped around the ends of sediment control wattle 100 and an adjacent sediment control wattle and secured to the ground with pins, similar to that described for FIG. 8 and FIG. 9 above.
[0048] FIG. 11 shows an alternate apron configuration in cross section for sediment control wattle 200 . Apron 212 formed by first and second layers 213 and 214 of geotextile sewn together at longitudinal seam 215 and at apron stitching 221 near an outside edge of apron 212 forming pocket 225 and filled with an anchoring media 222 such as pea gravel. Anchoring media 222 may be bound to apron 212 with an adhesive to assure consistent distribution. The sheath 211 , longitudinal seam 215 and sheath filler media 220 are similar to that described for FIG. 5 . The purpose of this embodiment is for use on hard surfaces such as asphalt and concrete without the use of pins to fasten the sediment control wattle in place.
[0049] FIG. 12 shows an alternate apron and sheath configuration in cross section for sediment control wattle 300 , having an apron 312 formed by two layers 313 and 314 of geotextile extending to both sides of the sheath 311 , and sewn together at apron stitching 321 A and 321 B located at the outside edges of layers 313 and 314 forming pocket 325 which may be filled with an anchoring media 322 such as pea gravel. Anchoring media 322 may be bound to apron 312 with an adhesive to assure consistent anchoring media 322 distribution. An alternate sheath configuration is shown in FIG. 12 , wherein sheath 311 is formed from a rectangular piece of geotextile separate from the apron 312 . As shown, sheath 311 is sewn to the top of apron 312 along both sides of the sheath 311 at longitudinal seams 315 A and 315 B. Sheath filler media 320 is similar to that described for FIG. 5 . The purpose of this embodiment is for use on hard surfaces such as asphalt and concrete without the use of pins to fasten the sediment control wattle in place.
[0050] In an alternate embodiment, an apron includes a plurality of discreet or separate pocket compartments similar to those shown in FIGS. 11 and 12 to reduce migration of the anchoring media. In yet another alternate embodiment, pockets of the type shown in FIGS. 11 and 12 may be configured as re-closable so that anchoring media may be added or removed as desired.
[0051] It is to be understood that the invention is not limited to the embodiment shown and described above. Various other embodiments of the invention may be made and practiced without departing from the scope of the invention, as defined in the following claims.
|
A sediment control wattle including a sheath formed of a geotextile, the sheath containing a filler media. An apron extends from the sheath providing an element that may be pinned or otherwise attached to a terrain in a manner that reduces migration and flow of fluid and sediment underneath the wattles. The sediment control wattle may also include a joint wrap which permits adjacent wattles to be joined to form a sediment control system in a manner that reduces migration and flow of fluid and sediment between wattles.
| 4
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of this invention are generally related to safety valves. More particularly, embodiments of this invention pertain to subsurface safety valves configured to control fluid flow through a production tubing string.
2. Description of the Related Art
Surface-controlled, subsurface safety valves (SCSSVs) are commonly used to shut in oil and gas wells. Such SCSSVs are typically fitted into a production tubing in a hydrocarbon producing well, and operate to block the flow of formation fluid upwardly through the production tubing should a failure or hazardous condition occur at the well surface.
SCSSVs are typically configured as rigidly connected to the production tubing (tubing retrievable), or may be installed and retrieved by wireline, without disturbing the production tubing (wireline retrievable). During normal production, the subsurface safety valve is maintained in an open position by the application of hydraulic fluid pressure transmitted to an actuating mechanism. The hydraulic pressure is commonly supplied to the SCSSV through a control line which resides within the annulus between the production tubing and a well casing. The SCSSV provides automatic shutoff of production flow in response to one or more well safety conditions that can be sensed and/or indicated at the surface. Examples of such conditions include a fire on the platform, a high/low flow line pressure condition, a high/low flow line temperature condition, and operator override. These and other conditions produce a loss of hydraulic pressure in the control line, thereby causing the flapper to close so as to block the flow of production fluids up the tubing.
Most surface controlled subsurface safety valves are “normally closed” valves, i.e., the valves utilize a flapper type closure mechanism biased in its closed position. In many commercially available valve systems, the bias is overcome by longitudinal movement of a hydraulic actuator. In some cases the actuator of the SCSSV includes a concentric annular piston. Most commonly, the actuator includes a small diameter rod piston, located in a housing wall of the SCSSV.
During well production, the flapper is maintained in the open position by a flow tube down hole to the actuator. From a reservoir, a pump at the surface delivers regulated hydraulic fluid under pressure to the actuator through a control conduit, or control line. Hydraulic fluid is pumped into a variable volume pressure chamber (or cylinder) and acts against a seal area on the piston. The piston, in turn, acts against the flow tube to selectively open the flapper member in the valve. Any loss of hydraulic pressure in the control line causes the piston and actuated flow tube to retract, which causes the SCSSV to return to its normally closed position by a return means. The return means serves as the biasing member, and typically defines a powerful spring and/or gas charge. The flapper is then rotated about a hinge pin to the valve closed position by the return means, i.e., a torsion spring, and in response to upwardly flowing formation fluid.
In recent completion techniques, an SCSSV may be run with the production tubing into the hole prior to a cementing operation. Once the cement is cured, the desired formations are perforated through the tubing. Using this technique, however, exposes the SCSSV to the cement during the cementing operation, which may cause the SCSSV to fail prematurely.
Therefore, a need exists for an apparatus and method for protecting the SCSSV from cement infiltrating the SCSSV during the cementing operation.
SUMMARY OF THE INVENTION
Various embodiments of the present invention are generally directed to a subsurface safety valve assembly for controlling fluid flow in a welibore. In one embodiment, the subsurface safety valve assembly includes a tubular member having a longitudinal bore extending therethrough and a flapper removably connected to the tubular member. The flapper is configured to pivot against the tubular member between an open position and a closed position. The subsurface safety valve assembly further includes a flow tube disposed inside the tubular member and a shear sleeve having an upper end and a lower end. The upper end of the shear sleeve is positioned against a lower end of the flow tube to form a first seal between the upper end of the shear sleeve and the lower end of the flow tube.
Various embodiments of the present invention are also directed to a system for protecting well completion equipment from at least one of cement or fluids during a cementing operation. In one embodiment, the system includes a sleeve removably disposed inside the well completion equipment and a dart configured to pull the sleeve away from the well completion equipment after the cementing operation is complete.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 illustrates a schematic of a production well having a subsurface safety valve installed in accordance with an embodiment of the invention.
FIG. 2 illustrates a cross-sectional view of the subsurface safety valve assembly in an open position in accordance with an embodiment of the invention.
FIG. 3 illustrates a shear sleeve in accordance with an embodiment of the invention in greater detail.
FIG. 4 illustrates a seal formed by a flow tube positioned against a hydraulic chamber housing in accordance with an embodiment of the invention.
FIG. 5 illustrates the shear sleeve in a position following the completion of a cementing operation in accordance with an embodiment of the invention.
FIG. 6 illustrates a system for protecting well equipment from cement or other fluids during the cementing operation in accordance with an embodiment of the invention.
FIG. 7 illustrates the manner in which a sleeve is coupled to a well equipment in accordance with an embodiment of the invention.
FIG. 8 illustrates o ring grooves defined on the upper nipple in accordance with an embodiment of the invention.
FIG. 9 illustrates the manner in which a dart connects to the sleeve in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A detailed description will now be provided. Various terms as used herein are defined below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term, as reflected in printed publications and issued patents. In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals. The drawings may be, but are not necessarily, to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the invention. One of normal skill in the art of subsurface safety valves will appreciate that the various embodiments of the invention can and may be used in all types of subsurface safety valves, including but not limited to tubing retrievable, wireline retrievable, injection valves, or subsurface controlled valves.
FIG. 1 illustrates a subsurface safety valve assembly 10 placed in a typical well completion schematic 12 in accordance with an embodiment of the invention. A land well is shown for the purpose of illustration; however, it is understood that the subsurface safety valve assembly 10 may also be used in offshore wells. FIG. 1 further illustrates a wellhead 20 , a master valve 22 , a flow line 24 , a casing string 26 and a production tubing 28 . In operation, opening the master valve 22 allows pressurized hydrocarbons residing in a producing formation 32 to flow through a set of perforations 34 and into the well 12 . Cement seals an annulus 35 between the casing 26 and the production tubing 28 in order to direct the flow of hydrocarbons. Hydrocarbons (illustrated by arrows) flow into the production tubing 28 through the subsurface safety valve assembly 10 , through the wellhead 20 , and out into the flow line 24 .
FIG. 2 illustrates a cross-sectional view of the subsurface safety valve assembly 10 in an open position, i.e., prior to the completion of a cementing operation. An upper nipple 36 and a lower sub 38 serve to sealingly connect the safety valve assembly 10 to the production tubing (not shown). The safety valve assembly 10 is generally maintained in the open position by hydraulic pressure. Hydraulic pressure is supplied by a pump (not shown) in a control panel (not shown) through a control line (not shown) to the safety valve assembly 10 . The hydraulic pressure holds a flapper closure mechanism 18 within the safety valve assembly 10 in the open position.
As the safety valve assembly 10 is hydraulically actuated, the safety valve assembly 10 includes a hydraulic chamber housing 40 and a piston 42 therein, as shown in FIG. 2 . The piston 42 is typically a small diameter piston which moves within a bore of the housing 40 in response to hydraulic pressure from the surface. Alternatively, the piston 42 may be a large concentric piston which is pressure actuated. It is within the scope of the present invention, however, to employ other less common actuators such as electric solenoid actuators, motorized gear drives and gas charged valves (not shown). Any of these known or contemplated means of actuating the subsurface safety valve assembly 10 of the present invention may be used.
In accordance with an embodiment of the invention, the safety valve assembly 10 further includes a shear sleeve 200 . The shear sleeve 200 is configured to eliminate or reduce the amount of cement and/or fluids from entering the safety valve assembly 10 . FIG. 3 illustrates the shear sleeve 200 in greater detail. At one end (e.g., the top end), the shear sleeve 200 is positioned against a lower end of the flow tube 44 , thereby forming a seal 210 sufficient to keep the cement from entering the safety valve assembly 10 . Seal 210 may be formed by pressing the upper end of the shear sleeve 200 against the lower end of a flow tube 44 . Seal 210 may be any type of sealing mechanism, such as a metal to metal seal or an elastomeric seal. In one embodiment, a temporary holding mechanism, such as a pin 250 , holds the shear sleeve 200 in place at a groove 255 defined on a portion of the outside diameter of the shear sleeve 200 . Other temporary holding mechanisms, such as shear screw, collet, and the like, may also be used to hold the shear sleeve 200 in place. In another embodiment, the safety valve assembly 10 further includes a retention sub 225 disposed between the shear sleeve 200 and the lower sub 38 . The retention sub 225 has an inside diameter that is larger than an outside diameter of the shear sleeve 200 . The larger diameter of the retention sub 225 may be configured to either provide sufficient space for the cement to accumulate or for the movement of the shear sleeve 200 when the flow tube 44 is actuated, which will be described in detail in the following paragraphs. As shown in FIG. 3 , the shear sleeve 200 may be coupled to the retention sub 225 by a threaded ring 235 and an o ring 230 . The threaded ring 235 may also be used to drive the sleeve 200 against the flow tube 44 to create seal 210 .
In yet another embodiment, an upper end of the flow tube 44 may be positioned, e.g., pressed, against the hydraulic chamber housing 40 , thereby forming seal 410 , as shown in FIG. 4 . Seal 410 is configured to eliminate or reduce the amount of cement entering the top portion of the safety valve assembly 10 . Like seal 210 , seal 410 may be any type of sealing mechanism, including metal to metal seal or elastomeric seal. In this manner, the shear sleeve 200 , in combination with the retention sub 225 , seal 210 , and seal 410 , is configured to substantially eliminate or reduce the amount of cement and/or fluids entering the safety valve assembly 10 .
In operation, the safety valve assembly 10 mounted on the production tubing 28 is run into the weilbore prior to the cementing operation. After the cementing operation is complete, the piston 42 is actuated to push the shear sleeve 200 through the retention sub 225 to the lower sub 38 . The piston 42 is actuated by application of hydraulic pressure through a control line 16 coupled to a controller 14 (See FIG. 1 ). The piston 42 , in turns, acts upon the flow tube 44 , translating the flow tube 44 longitudinally to such an extent that the pin 250 is sheared. The flow tube 44 continues to push the shear sleeve 200 toward the lower sub 38 until a snap ring 510 , which was previously disposed in a recess 520 defined inside the threaded ring 235 , snaps into a groove 530 defined on the outside diameter of the shear sleeve 200 . (See FIG. 5 ). The snap ring 510 is configured to hold the shear sleeve 200 in place after the flow tube 44 moves the shear sleeve 200 away from the flapper mechanism 18 . Other holding mechanisms may also be used to hold the shear sleeve 200 in place after the flow tube 44 moves the shear sleeve 200 away from the flapper mechanism 18 . The shear sleeve 200 may be pushed all the way to the bottom of the lower sub 38 . In this manner, after the cementing operation is complete, the shear sleeve 200 is shifted to a location that would not interfere with the operation of the safety valve assembly 10 , thereby eliminating the need to retrieve the shear sleeve 200 to the well surface. After the shear sleeve 200 is shifted away from the flapper mechanism 18 , the pressure (or energy) may be released from the piston 42 , thereby causing a power spring 46 to move the flow tube 44 longitudinally upward, allowing the flapper mechanism 18 to close.
FIG. 6 illustrates another way to protect a safety valve assembly 610 from being infiltrated by cement or other fluids during the cementing operation. That is, FIG. 6 illustrates a cross-sectional view of the safety valve assembly 610 disposed between an upper nipple 636 and a lower sub 638 . A sleeve 650 is disposed inside the safety valve assembly 610 . The sleeve 650 may be commonly referred to as a hold open sleeve. The sleeve 650 may extend from the upper nipple 636 to the lower sub 638 , and beyond. The sleeve 650 may be made from a disposable material, such as, aluminum, plastic, brass, steel and the like. The sleeve 650 includes a collar 710 defined on a portion of the outside diameter of the sleeve 650 , as shown in FIG. 7 . In one embodiment, the collar 710 is a shear out collar. FIG. 7 further illustrates recess 720 defined on an inside portion of the lower sub 638 . The collar 710 and recess 720 are configured to hold the sleeve 650 in place inside the safety valve assembly 610 during the cementing operation. In one embodiment, recess 720 may be defined in an inside portion of a retention sub 730 , which is coupled to the lower portion of the lower sub 638 . FIG. 8 illustrates that the upper nipple 636 may define o ring grooves 810 configured to provide one or more seals, thereby preventing cement and or other fluids from seeping into the top portion of the safety valve assembly 610 .
FIG. 6 further illustrates a dart 660 configured to pull the sleeve 650 away from the safety valve assembly 610 after the cementing operation is complete. An upper outside portion of the dart 660 defines a shoulder 910 , as shown in FIG. 9 . FIG. 9 also illustrates a lip 920 defined on a portion of the inside diameter of the sleeve 650 . The outside diameter of the shoulder 910 is greater than the inside diameter of the lip 920 . In this manner, the lip 920 performs as a no go sub, and the shoulder 910 is configured to catch or latch on to the lip 920 when the dart 660 is actuated, which will be described in detail in the following paragraphs.
In operation, the safety valve assembly 610 mounted on the production tubing 28 along with the sleeve 650 are run into the weilbore prior to the cementing operation. During the cementing operation, the sleeve 650 protects the safety valve assembly 610 from the cement or other fluids contained inside the tubing. After the cementing operation is complete, the dart 660 is used to pull the sleeve 650 away from the safety valve assembly 610 to allow the safety valve assembly 610 to operate without any interference from the sleeve 650 . In this manner, it is no longer necessary to retrieve the sleeve 650 following completion of the cementing operation. The dart 660 is may be pumped down through the production tubing 28 following the cement as the cementing operation is being completed. The dart 660 is generally actuated or driven by cement completion pumps (not shown). When the sleeve 650 is pulled away, the collar 710 collapses, thereby no longer holding the sleeve 650 inside the safety valve assembly 610 . In one embodiment, the sleeve 650 may be pulled all the way down to a rat hole or the bottom of the well. After the sleeve 650 is positioned away from safety valve assembly 610 , the safety valve assembly 610 is free to operate in a normal fashion. Following the completion of the cementing operation, the pressure (or energy) may be released from the piston 42 , causing the power spring 46 to move the flow tube 44 longitudinally upward, thereby allowing the flapper mechanism 18 to close.
Although the invention has been described in part by making detailed reference to specific embodiments, such detail is intended to be and will be understood to be instructional rather than restrictive. It should be noted that while embodiments of the invention disclosed herein, particularly those embodiments described with reference to FIG. 6 et seq., are described in connection with a subsurface safety valve assembly, the embodiments described herein may be used with any well completion equipment, such as a packer, a sliding sleeve, a landing nipple and the like.
Whereas the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, might be made within the scope and spirit of the present invention.
|
A subsurface safety valve assembly for controlling fluid flow in a wellbore. In one embodiment, the subsurface safety valve assembly includes a tubular member having a longitudinal bore extending therethrough, a flapper removably connected to the tubular member. The flapper is configured to pivot against the tubular member between an open position and a closed position. The subsurface safety valve assembly further includes a flow tube disposed inside the tubular member and a shear sleeve having an upper end and a lower end. The upper end of the shear sleeve is positioned against a lower end of the flow tube to form a first seal between the upper end of the shear sleeve and the lower end of the flow tube.
| 4
|
FIELD OF THE INVENTION
This invention relates to a coating composition for forming the surface coat of a carrier to be used in a two-component developer for a dry processable copying machine. More particularly, it is concerned with a silicone composition to be coated onto a carrier surface for the purpose of preparing a carrier which is excellent in durability, moisture resistance and flowability.
BACKGROUND OF THE INVENTION
A two-component developer for a dry processable copying machine, as is well-known, comprises two components, viz., a finely divided toner and a carrier which is larger than the toner in particle size. When mixed and agitated, both components are statically electrified by rubbing, and charges are gained which are opposite in sign to each other. The thus electrified toner is made to adhere electrostatically to an electrostatic latent image formed on a photoreceptor, resulting in the formation of a visible image. This visible image is then transferred and fixed onto a transfer sheet, thus achieving duplication.
In the process as described above, oxidized or unoxidized iron powder has generally been used as the carrier. However, a carrier of this kind has defects, viz., the triboelectrification characteristics thereof is not satisfactory with respect to the toner, and what is worse, it changes with the lapse of time since strong adhesion of the toner to the carrier surface occurs with repeated use and forms a toner film thereon, resulting in the shortening of the developer's life span (so-called spent phenomenon). In addition, there is a large difference in electrification characteristics between carrier in a dry and in a humid atmosphere. More specifically, there exists such a problem that even if carriers exhibit excellent characteristics in Japan, they cannot display their abilities to the fullest in high temperature-high humidity places (e.g., Southeast Asia) whereto they have been exported.
With the intention of obviating the above-described defects, it has been proposed to coat on carrier surface a resin having low surface energy, such as a fluorine-containing resin or a silicone resin, (e.g., in Japanese Patent Kokai Nos. 54-21730 and 58-40557 (The term "Japanese Patent Kokai" as used herein means as "unexamined published Japanese patent application"), Japanese Patent Kokoku Nos. 59-131944 and 59-26945 (The term "Japanese Patent Kokoku" as used herein means an "examined Japanese patent publication"), etc.).
In particular, silicone resins can have various molecular structures depending on the constituent monomers selected for their synthesis, so they not only can be used for the production of carriers which have a wide variety of charge acceptance levels, but they also have many advantages from the working point of view, e.g., that they can be dissolved in various solvents, uniformly coated on the carrier surface with ease, set at relatively low temperatures, and so on.
On the other hand, silicone resins have a defect in that their mechanical strength is generally low, so they come off due to abrasion and generate cracks due to peeling-off after long hours of use, which results in a loss of their excellent characteristics, and a corresponding lowering of copying ability. Thus, silicone resins are not satisfactory with respect to lifespan upon long-term use.
One of the two components which constitute a developer, as the toner is consumed, new toner is supplied in a supplemental amount. On the other hand, a carrier is used continuously. However, it is impossible to restore a carrier's ability which has deteriorated due to continuous use. Therefore, the developer as a whole must be renewed when the carrier has undergone deterioration.
In recent years, requirements for carriers have become more stringent due to popularization of high-speed copying machines and the number of copies needed becomes larger and larger. Therefore, a treatment with conventional silicone resins cannot cope with the present situation.
In addition, the renewal of developer is disadvantageous in cost, as well as being bothersome. Under these circumstances, it was an objective to develop novel carrier-treating agents in high durability.
SUMMARY OF THE INVENTION
As a result of examining various silicone compositions as the surface coat of carriers, it has now been found that remarkably favorable results, that is, both with respect to retention of the merits of silicone resins and attainment of long life and high stability, can be effected by selecting a combination of certain organopolysiloxanes and organohydrogenpolysiloxanes, adding thereto a setting catalyst, coating the resulting composition on a carrier surface, and then setting the coated composition, thus achieving this invention.
Therefore, a first object of this invention is to provide a coating composition useful as the surface coat of electrophotographic carrier which enables prolongation of a developer's life by suppression of the before-mentioned spent phenomenon.
A second object of this invention is to provide a coating composition for surface coating an electrophotographic carrier which can prevent the electrification characteristics of the carrier from being adversely affected by the temperature of the atmosphere.
In a composition aspect, this invention is a coating composition for an electrophotographic carrier, which comprises components (A), (B) and (C):
(A) 100 parts by weight of a compound represented by the general formula (1);
R.sub.a X.sub.b SiO.sub.(4-(a+b))/2
(wherein R represents a substituted or unsubstituted hydrocarbon residue; X represents a hydroxyl group or a hydrolyzable group; "a" is a number in the range of 0.8<a<1.8; and "b" is a number in the range of 0.01<b≦3),
(B) 0.05 to 50 parts by weight of an organohydrogenpolysiloxane having at least two hydrogen atoms bonded directly to a silicon atom, and
(C) a curing catalyst for (A) and (B).
DETAILED DESCRIPTION OF THE INVENTION
Each component used in the composition of this invention is described in detail below.
The component (A) of the composition of this invention is a compound represented by the general formula,
R.sub.a X.sub.b SiO.sub.(4-(a+b))/2
In the above formula, R is a group selected from among unsubstituted hydrocarbon residues including alkyl groups containing 1 to 6 carbon atoms, alkenyl groups such as vinyl group, allyl group, etc., and phenyl group, or substituted hydrocarbon residues including 3,3,3-trifluoropropyl group, tolyl group, xylyl group, benzyl group, chloroalkyl groups, p-chrorophenyl group, cyanoethyl group and so on. Among these groups, alkyl groups containing 1 to 4 carbon atoms, phenyl group and vinyl group are preferred in respect of availability. X is OH (silanol) group and/or a group selected from among hydrolyzable groups. Specific examples of hydrolyzable groups include alkoxy groups containing 1 to 4 carbon atoms, alkenoxy groups, acetoxy groups, aminoxy groups, oxime groups, halogen atoms, and the like. These groups each participates in curing after having once been converted to SiOH (silanol) by moisture adsorbed on the carrier surface in the course of a coating procedure or upon contact with humid air.
"a" in the general formula (1) can be a value in the range of 0.8 to 1.8. When "a" is below 0.8, the surface coat obtained is rigid and brittle, and tends to come off due to generation of cracks during the use, while when "a" is above 1.8 the resin formed readily causes thermal softening, so release of toner under high temperatures becomes difficult to effect smoothly. The most preferable range of "a" is from 1.0 to 1.5.
On the other hand, "b" in the general formula (1) can be a value in the range of 0.01 to 3.
When "b" is below 0.01, sufficient adhesiveness to the carrier surface cannot be obtained even though a surface coat thereof on the carrier can be formed. On the other hand, "b" can be up to a value of 3 so long as the surface coat is formed under such a condition that sufficient moisture can be supplied in the setting step. However, the most appropriate range of "b" is from 0.03 to 1.0.
An organohydrogenpolysiloxane to be used as the component (B) in this invention is an important component which is indispensable for enhancement of durability, and it is necessary for the organohydrogenpolysiloxane to have two or more of hydrogen atoms directly bonded to silicon atom(s) in a molecule.
As specific examples of the component (B), mention may be made of those represented by the following general formulae (2), (3) and (4). However, the component (B) should not be construed as being limited to these compounds. ##STR1## wherein the R's are the same kind, or two or more different kinds of groups selected from among hydrogen atom, alkyl groups, allyl groups, hydroxyl group and hydrolyzable groups, with the proviso that at least two of the R's are hydrogen atoms; m is a positive integer of 3 or more; and c ranges from 1.5 to 2.0.
Although component (B), can achieve its effects even when added in a small amount, it is preferably used in an amount from 0.05 to 50 parts by weight per 100 parts by weight of the component (A). When the component (B) is used in an amount less than 0.05 part by weight, the effect produced is insufficient. On the other hand, when the amount used is beyond 50 parts by weight, the resulting composition is poor in recoatability, so the use of the component (B) in such amounts is disadvantageous, particularly in forming a thick film through repeated recoating, for the purpose of the acquisition of long-period stability.
Accordingly, a particularly preferred content of the component (B) ranges from 0.1 to 10 parts by weight per 100 parts by weight of the component (A).
The component (C) is a curing catalyst, with specific examples including metal soaps which contain as a metal component Zn, Sn, Fe, Pb, Co, Ni, Al, Zr, and so on, chelate compounds, organic acids such as formic acid, acetic acid and the like, and bases such as amines, etc.
In particular, independent or combined use of organotin compounds, organoiron compounds and amino group-containing silane compounds can produce desirable effects.
Suitable examples of organotin compounds include dibutyltin diacetate, dibutytin dilaurate, dibutyltin dioctoate, stannous oleate, stannous naphthenate, and so on.
Suitable examples of organoiron compounds include iron octylate, iron naphthenate, iron (III) acetylacetonate, and so on.
Amino group-containing silane compounds include amino group-containing alkoxysilanes and partial condensates thereof, and can contribute to enhancement of adhesiveness to carrier surface, heightening of the surface hardness, controlling the quantity of the carrier, and so on.
Specific examples of such silane compounds include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminoethyl-aminopropyltrimethoxysilane, methyl-γ-aminopropyldimethoxysilane, methyl-γ-aminoethylaminopropyldimethoxysilane, γ-dimethylaminopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-morpholinopropyl-trimethoxysilane, N,N'-bis (3-trimethoxysilyl)ethlenediamine, and partial condensates of these silanes.
Both components (A) and (B) can be cured by nature on individual carrier core particles through some processing without using any catalyst. The reason why the catalysts illustrated as the component (C) should be nevertheless used in this invention is in their abilities to link the component (A) and the component (B) together and, at the same time, to make the silicone composition adhere firmly to individual surfaces of carrier core particles, as well as to function as a curing catalyst for each of the components (A) and (B), whereby the mechanical strength of the silicone coat can be remarkably heightened.
The organohydrogenpolysiloxane which constitutes component (A) and the organohydrogenpolysiloxane which constitutes component (B), which are the essential components of this invention, are both old and well-known in this field, and various methods for preparing them are known.
Examples of carrier core particles usable in this invention are iron powder, and ferrite powder. In addition to these powders, materials for the carrier core particles to be used in this invention can be properly chosen from known materials such as magnetic metals (e.g., nickel, cobalt, etc.), magnetic metal oxides, copper, carborundum, glass beads, silicon dioxide and so on. The diameter of such particles ranges from 30 to 1,000 microns, preferably from 50 to 300 microns.
In this invention, the silicone composition constituted by the above-described ingredients is dissolved in an organic solvent (e.g., hydrocarbon solvents such as toluene, xylene, solvent naphtha, etc., alcohols, esters, ketones, ethers, and so on), if necessary, and then coated on individual carrier core particles using, e.g., a fluidized bed process, a dipping process, a spraying process and so on, followed by drying and curing.
A preferred thickness of the coat is from 0.1 to 20 microns. The same silicone composition can be recoated, if needed. Also, different silicone compositions may be coated in layers, if desired.
Curing of the silicone composition of this invention, though can be achieved at ordinary temperature, is preferably carried out under heating to about 100° C.-250° C., because the heating can stabilize the characteristics of the coat and increase the production speed.
Toner, which is another component of a developer and has to be used in combination with the carrier coated with this silicone composition, does not have any particular limitation in this invention. It can be prepared from dispersions of known various synthetic dyes in a wide variety of materials including natural resins, and resins modified by the combined use of natural and synthetic resins.
The coating composition of this invention has been found to be uniformly coated with ease on individual core particle of electrophotographic carrier, and to impart considerably enhanced durability to the resulting carrier as it is endowed with merits of a silicone composition, such as an ability to prevent a spent phenomenon due to facility in releasing toner, an ability to heighten moisture resistance, an ability to control charging capacity, and so on.
This invention will now be illustrated in more detail by reference to the following examples and comparative examples.
EXAMPLE 1
100 pts. wt. of an organopolysiloxane represented by the average composition formula, (CH 3 ) 1 .15 (OH) 0 .2 SiO 1 .325, and having an average molecular weight of about 2,500, 5 pts. wt. of an organohydrogenpolysiloxane represented by the formula, ##STR2## and 420 pts. wt. of solvent naphtha were admixed, and made into a solution. Further, 0.2 pt. wt. of dibutyltin laurate was added thereto, and rendered homogenous by stirring to obtain a silicone composition for a carrier coat.
Then, ferrite having an average particle size of 100 microns was prepared as carrier core particle, and the obtained silicone composition was sprayed thereonto using a fluidized bed apparatus so that silicone coat might amount to 20 g per 1 Kg of the ferrite.
Thereafter, the coat was heated at 200° C. for 60 minutes to set the silicone component.
To a 30 g portion of the thus processed carrier powder, 1.2 g of styrene-carbon black type toner having an average particle size of 12 microns was added, and electrified by vibrating. A quantity of electrification of the toner was measured with a blowoff type electrified powder's electrification measuring apparatus made by Toshiba Chemical K.K..
Further, a 1 Kg portion of the carrier and a 40 g portion of the toner were placed in a forced deterioration device which was made of porcelain and had a volume of 500 ml, and submitted to a forced deterioration test by vigorously vibrating the device in the horizontal direction with an amplitude of 4 cm and a frequency of 370 times per minute.
This forced deterioration test continued for 30 minutes was comparable to copying of about 5,000 sheets in an actual copying machine.
As the result of measurements, a quantity of the initial electrification was 32 μc/g, expressed in terms of 30 seconds' blowoff value, while the value after the 10 hours' forced deterioration test was 30 μc/g. That is, there was a slight difference between them.
Thus, the developer of this invention has proved to have excellent durability.
COMPARATIVE EXAMPLE 1
A carrier powder was prepared by processing the same carrier core particles as used in Example 1 under the same condition as in Example 1, except the organohydrogenpolysiloxane used in Example 1 was not employed and the amount of solvent naphtha was changed to 400 pts. wt., and its characteristics were examined. A quantity of the initial electrification was 33 μc/g, which was almost the same to the value obtained in Example 1. However, the quantity was decreased to 18 μc/g after 10 hours' forced deterioration test, and this carrier was clearly unfit for developer in practical use.
COMPARATIVE EXAMPLE 2
A carrier powder was prepared in the same manner as in Example 1, except dibutyltin dilaurate used in Example 1 was not employed. Characteristics of the carrier powder was examined in accordance with the same process as in Example 1. A quantity of the initial electrification was 33 μc/g, but the quantity was decreased to 9 μc/g by the 10 hours' forced deterioration.
Therefore, this carrier powder was also unfit for developer in practical use.
EXAMPLE 2
To 100 pts. wt. of an organopolysiloxane having the average composition formula,
(CH.sub.3).sub.1.1 (C.sub.6 H.sub.5).sub.0.15 (OH).sub.0.25 SiO.sub.1.25,
and an average molecular weight of about 2,000 was added 10 pts. wt. of an organohydrogenpolysiloxane having the formula,
(OH).sub.0.15 (CH.sub.3).sub.0.7 H.sub.0.5 (C.sub.6 H.sub.5).sub.0.15 SiO.sub.1.25
and an average molecular weight of 3,200. Thereto were further added 86 pts. wt. of toluene and 171 pts. wt. of solvent naphtha to make them into a solution. Furthermore, 0.5 pt. wt. of iron octoate was added to the solution, and mixed homogeneously therewith to prepare a silicone composition for carrier coat. Under the same condition as adopted in Example 1, the same carrier core particles as used in Example 1 were treated with the thus prepared silicone composition, and characteristics of the resulting carrier was examined. As the results, a quantity of the initial electrification was 21 μc/g, and that after the 10 hours' forced deterioration was on a level of 18 μc/g.
EXAMPLE 3
The carrier core particles were processed under the same condition as in Example 2, except 0.3 pt. wt. of γ-aminopropyltrimethoxysilane (produced by Shin-Etsu Chemical Co., Ltd.: trade name, KBM-903) was used in place of iron octoate, and then examined for electrification quantity.
A quantity of the initial electrification was 37 μc/g, and that after the 10 hours' forced deterioration was on a level of 36 μc/g.
COMPARATIVE EXAMPLE 3
The carrier core particles were processed under the same condition as in Example 3, except the organohydrogenpolysiloxane used in Example 3 was not employed and the amount of solvent naphtha was changed to 141 pts. wt., and the thus obtained carrier powder was examined for electrification quantity similarly to Example 3. A quantity of the initial electrification was 36 μc/g, but it was changed to 23 μc/g after the 10 hours' forced deterioration. That is, a large difference was caused therebetween.
EXAMPLE 4
To 100 pts. wt. of the organopolysiloxane having the average composition formula, (CH 3 ) 1 .15 X 0 .2 SiO 1 .325 (wherein X is methyldi(methylethylketoxime) silyl group), and a mean molecular weight of 3,900 were added 3 pts. wt. of the same organohydrogenpolysiloxane as used in Example 1, 77 pts. wt. of toluene and 232 pts. wt. of solvent naphtha to prepare a silicone composition for carrier coat.
The carrier core particles were processed under the same condition as in Example 1, and the carrier powder obtained was examined for electrification quantity.
A quantity of the initial electrification was 33 μc/g, and that after the 10 hours' forced deterioration was on a level of 32 μc/g.
COMPARATIVE EXAMPLE 4
The carrier core particles were processed in the same manner as in Example 4, except organohydrogenpolysiloxane used in Example 4 was not employed and the amount of solvent naphtha was changed to 223 pts. wt., and the thus obtained carrier powder was examined for electrification quantity. A quantity of the initial electrification was 33 μc/g, but it was decreased to 13 μc/g after the 10 hours' forced deterioration.
Therefore, this carrier powder was also unfit for developer in practical use.
EXAMPLE 5
To 100 pts. wt. of an organopolysiloxane having the average composition formula (CH 3 ) 1 .2 (OCH 3 ) 1 .2 SiO 0 .8 and a mean molecular weight of about 480 were added 20 pts. wt. of the same organohydrogenpolysiloxane as used in Example 1, 180 pts. wt. of toluene and 180 pts. wt. of solvent naphtha. Thereto, 0.5 pt. wt. of dibutyltin diacetate was further added to prepare a silicone composition for carrier coat. Under the same condition as adopted in Example 1, the same carrier core particles as used in Example 1 were treated with the thus prepared silicone composition, and characteristics of the thus obtained carrier powder was examined. As the result, the initial electrification quantity was 35 μc/g, and that after the 10 hours' forced deterioration was on a level of 33 μc/g.
COMPARATIVE EXAMPLE 6
The carrier core particles were processed in the same manner as in Example 5, except the organohydrogenpolysiloxane used in Example 5 was not employed and the amount of toluene was changed to 120 pts. wt., and the thus obtained carrier powder was examined for electrification quantity. A quantity of the initial electrification was 31 μc/g, but it was sharply changed to 19 μc/g after the 10 hours' forced deterioration.
The results obtained in the examples and the comparative examples illustrated above clearly demonstrate the advantage of this invention.
|
A coating composition to form a coat on the surface of electrophotographic carrier which imparts excellent durability, moisture resistance and flowability to the carrier comprises:
(A) 100 parts by weight of an organopolysiloxane of the general formula;
R.sub.a X.sub.b SiO.sub.(4-(a+b))/z
wherein R represents a substituted or unsubstituted hydrocarbon residue; X represents a hydroxyl group, or a hydrolizable group; "a" is a number in the range of 0.8<a<1.8; and "b" is a number in the range of 0.1<b≦3,
(B) 0.05 to 50 parts by weight of an organohydrogenpolysiloxane having at least two hydrogen atoms bonded directly to silicon atom, in a molecule, and
(C) a curing catalyst.
| 6
|
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to a linear actuator comprising a brushless multiphase electric motor, including a stator and a rotor, the latter acting on a control organ through driving means designed capable of converting, over several revolutions, its rotational movement into a linear displacement.
The present invention relates to the field of the linear actuators generally including a brushless multiphase electromagnetic motor. It finds a very particular application in the case in which a control in the form of a fast linear displacement is sought, as is necessary, for example, for controlling the valve of a device for re-circulating the exhaust gases of a diesel motor, but also for controlling air-inlet valves.
(2) Description of the Prior Art
Nowadays, for such applications use is made of direct-drive linear electromagnetic actuators or linear actuators based on an electric stepping motor using a system for converting the rotational movement into a linear displacement, such systems being capable of adopting various embodiments. In particular, cam systems, pinion and rack systems and screw and nut systems are known.
From DE-A-100 03 129 is known in particularly a linear actuator including a stepping motor provided with a rotor provided, on its periphery, with magnets of alternate polarity in front of pole shoes of a stator. It includes at least two electric field coils allowing to control the motor through electronic switching. It should be noted that in the axial extension of the stator is provided for a Hall sensor surrounding the rotor as a position-detection device.
Turning back to the rotor, it includes, internally and coaxially, a tapped nut engaging a threaded rod immobilized in rotation.
Thus, from the action of the rotation of the rotor and, hence, of the nut integral with the latter, results a displacement in translation of the threaded rod which substantially forms the control organ.
The problem raised by this kind of linear actuator with a multiphase motor consisted in that, in the event of failure of the motor, even if due to an interruption of power supply, the control organ and, hence, the part, for example the valve on which it acts, remains in the position reached before the failure occurs. Therefore, since it does not return into a safety position, this can result into a more serious dysfunction at the level of the unit in which this controlled part fits.
When taking, for example, the particular case of the control of valves of a device for re-circulating exhaust gases of a diesel motor, it is imperative that these valves be maintained closed on their seat, so as to prevent the exhaust gases from being re-circulated when such a failure occurs, for otherwise the operating conditions of the motor itself will be altered.
Therefore and as described in U.S. Pat. No. 4,501,981, there has been devised to provide this kind of actuator with a stepping motor with springy restoring means capable of restoring the threaded rod into a reference position in the event of power fail. Though these springy restoring means can adopt the shape of a helical spring acting directly on the threaded rod, in a second embodiment described in this document U.S. Pat. No. 4,501,981 a helical spring can also act on the rotor in order, in the event of such a power fail, to control the later in rotation and to restore the control organ into its reference position.
However, it should be noted that a D.C. multiphase stepping motor raises a problem of response time and jerked displacement since a magnetized pole of the rotor has a privileged balanced position when it is placed in front of a pole of the stator or when a transition between two magnetic poles is located in front of such a stator pole.
The residual torque is thus a periodic function of the angular position the frequency of which depends on the number of magnetic poles and on the number of stator poles.
Finally, the stepping motor has two kinds of significant drawbacks for both ensuring a fast control of an organ and allowing the latter to be easily restored into a reference position under the action of a springy restoring:
the residual torque, which corresponds to the torque without current of the motor, is excessive and prevents an easy restoring into a reference position, the principle of operation of the stepping motor only allows controlling a displacement, without having the possibility of checking whether the imposed sequence has been carried out correctly.
In this respect, in FR-A-2,754,953 has described a brushless and electronically switched multiphase motor having a low residual torque. In particular, the stator portion of this motor has at least two W-shaped circuits including, each, an electric coil surrounding the central stator pole. These W-shaped circuits are so arranged that, when one central stator pole is located in front of a magnetic transition, the other central stator pole is located roughly in front of a magnetic pole. The pole shoes of these central stator poles of the two W-shaped circuits belong to different phases and are angularly separated by 120°. Thus, the shape of the W-shaped stator circuit ensures the closing of the field lines between the central pole which receives the coil and both adjacent poles.
SUMMARY OF THE INVENTION
Therefore, within the framework of an inventive step it has been devised to associate with such a linear electric actuator with a brushless multiphase motor:
springy and/or magnetic restoring means allowing to systematically restore into a reference position the control organ on which has to act the rotor in the event of an interruption of power supply to the motor; and a position-detection device contributing, in combination with an electronic control unit, to the control or adjustment of the position of the rotor, hence of the control organ.
According to an embodiment of the invention, these springy and/or magnetic restoring means are in the form of at least one springy and/or magnetic element for controlling the rotation of the rotor.
It is obvious that, when the actuator operates normally, the motor must oppose the reverse action of such a springy and/or magnetic element for controlling the rotation. Accordingly, the motor must be sized so as to produce a sufficient torque to be able to bring the control organ from one extreme position to another, for example from a closed position of a valve to its open position, and, at the same time, to counteract the resistive torque provided by the springy and/or magnetic element. Conversely, it should be designed capable of systematically restoring this control organ into its reference position.
In this respect, it should be noted that such a springy and/or magnetic element must provide a lower torque as the motor has, in turn, a reduced residual torque.
It should also be noted that the action of this springy and/or magnetic element acting directly on the rotor also counteracts the performances of the motor from the point of view of its maintenance torque, i.e. the continuous torque it is capable of producing to maintain the controlled part, for example a valve, in open position.
According to another embodiment, the springy restoring means are designed in the form of at least one springy and/or magnetic element capable of acting directly on the control organ. This obviously implies that the driving means for converting the rotational motion of the rotor into a linear movement are reversible. Now, in a simple design corresponding to the state of the art described in FR-A-2,754,953 in the form of a screw and nut unit, the reversible nature of such driving means directly depends on the reduction they provide. All things considered, the larger the transmission ratio, the smaller will be the effort the springy and/or magnetic element will have to produce for restoring it, through a direct action on the control organ, into a reference position. Obviously, the motor must then be capable of providing a larger torque, in order to be able to act on this control organ.
Thus, according to a third embodiment, springy and/or magnetic restoring means have been devised in the form of a combination of a springy and/or magnetic element for controlling the rotation of the rotor and another one acting directly on the control organ, both acting for the same purpose.
It should also be noted that the combination of such springy and/or magnetic elements allows minimizing the contact pressures at the interface of the moving parts of the driving means designed capable of converting the rotational motion into a linear displacement, such contact pressures resulting into degrading, in the course of time, the friction coefficient between these parts, which coefficient the reversibility of the movement is also subjected to.
Another advantage resulting from the present invention consists in that the springy and/or magnetic element or elements contribute to eliminating the mechanical backlash between the moving parts, which allows avoiding or reducing the operating noises of the actuator as well as the shocks during the transitional phase of starting and stopping.
Also advantageously, with the driving means for converting the rotational motion of the rotor into a linear movement is associated an independent reversible reduction device. This uncoupling of the speed-reduction and motion-conversion functions allows using a large pitch at the level of the helical system, of the screw and nut type or the like, ensuring the latter function. The reduction device is then independently parameterized, knowing that its output is substantially constant with respect to the reduction. Finally, this separation of the functions provides, for the same reduction, a higher total output, compared to the use of only a helical system.
Further objects and advantages of this invention will become clear during the following description.
The understanding of this description will be made easier when referring to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and axial cross-sectional view of a linear electric actuator with a multiphase motor according to the invention;
FIG. 2 is a view similar to FIG. 1 , showing a second embodiment that integrates a linear position sensor;
FIG. 3 is a cross-sectional view showing a third embodiment in which the rotor is fitted like a nut on its axis defined in the form of a threaded rod;
FIG. 4 is a schematic view of the kinematics of an actuator including a reduction gear in the form of an epicyclical gear and driving means designed capable of converting the rotational motion into a linear displacement in the form of a screw and nut system;
FIG. 5 is a view similar to FIG. 4 , the driving means designed capable of converting the rotational motion into a linear displacement adopting the form of a roller and of a cam;
FIG. 6 is a schematic view of the kinematics of an actuator including a reduction gear in the form of a differential gear and driving means designed capable of converting the rotational motion into a linear displacement in the form of a screw and nut system;
FIG. 7 is a view similar to FIG. 6 , the means designed capable of converting the rotational motion into a linear displacement adopting the form of a roller and a cam;
FIG. 8 is a schematic view of an embodiment corresponding to the design according to FIG. 7 , but with two cams including crossed profiles and the relative rotation of which through the differential gear induces the sliding of a roller in the form of a pin causing the translation of the control organ.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 and 2 of the attached drawing, the present invention relates to a linear electric actuator 1 including brushless multiphase D.C. electric motor 2 , comprised of a stator 3 and a rotor 4 , the latter acting on driving means 5 which are designed capable of converting, over several revolutions, the rotational motion of this rotor 4 into a linear displacement 5 .
In the figures of the attached drawing are shown embodiments of these driving means 5 , but it should be noted that the present invention is by no means limited to them. In particular, such driving means 5 can adopt the form of devices with cams, pinion and rack, etc., without departing from the framework and the spirit of this invention.
Turning back to the motor 2 , its rotor 4 preferably includes N pairs of rotor poles 7 radially magnetized in an alternate direction, N being greater or equal to 4, while being different from a multiple of 3.
Furthermore and for achieving an as small as possible magnetostatic torque in the absence of current, the stator 3 includes, in turn, preferably P×9 identical poles 8 spaced apart by 40°/P, said stator poles 8 being grouped consecutively three by three, so as to define a phase made up of a W-shaped circuit, grouping three consecutive stator poles, the central stator pole 8 carrying the coil 9 of the corresponding phase 10 .
Moreover, the central stator poles 8 of two W-shaped circuits, each corresponding to a phase, are angularly spaced apart by 120°.
This motor 2 is of the brushless type, i.e. the coils 9 and, hence, the phases 10 are at least two in total and are supplied with power through an electronic control unit, not shown.
The motor 2 is accommodated in a casing 11 including, at one and/or the other of its ends, bearings 12 , 13 , maintaining the rotor 4 in rotation.
Turning back to the driving means 5 , they can be defined, as shown in FIGS. 1 , 2 , 3 , 4 and 6 , by a screw and nut system 14 . In particular and as can be seen in FIGS. 1 , 2 , 4 and 6 , at the level of an axial bore 15 , the rotor 4 carries a nut 16 engaged with a coaxial threaded rod 17 ; 17 A eventually emerging out of the casing 11 at least at one of its ends 18 . Thus, through the linear displacement which is imparted to it by the rotor 4 , this threaded rod 17 , 17 A defines, directly or indirectly, the control organ O of the actuator 1 .
In the embodiment corresponding to FIG. 3 , the nut 16 carried by the rotor 4 is mounted moveable on a fixed threaded rod 17 B. Thus, during the control of the rotation of the motor 2 , the rotor 4 moves according to a helical motion under a stator 3 extended for this purpose and transmits its linear displacement to the control organ O immobilized in rotation by adequate means.
In these embodiments corresponding to FIGS. 1 , 2 and 3 , this screw and nut system 14 also ensures the function of a reduction gear and in this case it is preferably of the ball screw type.
In the framework of the designs corresponding to the FIGS. 5 and 7 , these driving means 5 , designed capable of converting the rotational motion of the rotor 4 into a linear displacement adopt the form of a system 14 A of the type roller 40 and cam 41 . All things considered, the stem 42 , substantially corresponding to the control organ O, carries roller 40 evolving along a circular cam 41 put into rotation, directly or indirectly, as will be described below, by the rotor 4 .
The solution corresponding to FIG. 8 uses driving means 5 including the (or one) first cam 41 and one second cam 41 A with crossed profiles designed capable of being rotated with a differential speed, as is explained below in the description, to impart to a roller 40 A, in the form of a pin, an axial sliding capable of causing the translation of the control organ O.
This configuration has a higher output than that achieved with only a cam with a helical profile against which rests a roller likely to move exclusively in a rectilinear way.
Turning back in particular to the embodiment corresponding to FIGS. 1 and 2 , in a reference position, this threaded rod 17 abuts, through its end 19 inserted in the bore 15 of the rotor 4 , against a shoulder 20 which internally includes this bore 15 .
By way of an example, within the framework of an application to the control of a valve of a device for re-circulating exhaust gases of a diesel motor, the actuator can be aimed at controlling, starting from a closed position, the opening of a valve. In particular, the closed position corresponds in this case to a reference position.
In the embodiment shown, this reference position can correspond to the outward position of the threaded rod 17 , so that the power supply to the motor 2 and the rotation generated by the rotor 4 result into drawing the threaded rod 17 into its bore 15 in order, in the above example, to control the opening of said valve. This position can be maintained through the maintenance torque provided by the motor when its power supply is maintained.
According to the invention, this linear electric actuator includes, in combination, springy and/or magnetic restoring means 21 for restoring, in the event of interruption of power supply to the motor, its control organ O, here the threaded rod 17 , into its reference position.
In fact, these springy and/or magnetic restoring means 21 are defined capable of inducing several revolutions of the rotor 4 , in order to ensure this restoring into reference position of the control organ O.
Such springy and/or magnetic restoring means 21 can consist of a springy and/or magnetic element for controlling the rotation of the rotor 4 which, when said control organ O is restored from its reference position into any position, is put under constraint, so that it can be restored, through rotation of the rotor 4 , into this same reference position.
These springy and/or magnetic restoring means 21 can also be defined by a springy and/or magnetic element 23 acting directly on said control organ O in order to restore it into said reference position from any position into which it was previously brought by the motor 2 , this of course in the event of an interruption of the power supply to the latter.
Turning back to the springy and/or magnetic element 22 capable of imparting a rotational motion to the rotor 4 , it can be defined, as shown in FIGS. 1 and 2 , in the form of a helical spring engaged with the axis 24 of this rotor 4 extending beyond the stator 3 , on the opposite side with respect to the emerging end 18 of the threaded rod 17 .
The advantage of such a helical spring consists in that it is of a reduced size and which, in the case of small actuators, is capable of producing a sufficient torque to achieve the result sought. In particular, such a helical spring is capable of operating over several revolutions, even of producing a substantially constant restoring torque over the full travel distance of the actuator.
It should be noted that the restoring torque Co this springy element should produce must be such that:
Co>C friction +C residual
All things considered, this torque must be able to overcome the resistive torque produced by the frictions and the residual torque, i.e. the magnetostatic torque in the absence of current of motor 2 . It is therefore important that it is as small as possible, hence the design of the motor as defined above. Indeed, though it is appropriate to make the springy and/or magnetic element of higher stiffness, as a matter of fact in order to be capable of opposing a larger resistive torque, correlatively it is necessary to oversize the motor so that it is capable of producing a defined torque, not only to allow it to ensure the function of a requested actuator, but also to counteract the resistive torque which is necessarily provided by this springy element.
In the case of use of an elastic and/or magnetic element 23 acting directly on the control organ O, here the threaded rod 17 , the driving mechanism 5 must compulsorily be of a reversible type.
In the case of a system as described, threaded rod 17 and nut 16 , the criterion for the selection of the pitch is such that:
P>μπDia
where p is the pitch, Dia is the average diameter of the screw and μ is the friction coefficient between the threaded rod 17 and the nut 16 .
In such a motion-conversion system, the axial force F necessary to achieve the reversibility is such that:
F> 2 πC/pη′
where
C: residual torque in operation without current (magnetostatic torque without current+friction torque at the bearings)
η′: output of translation to rotation of the screw
Though it is also important here that the magnetostatic torque without current is as small as possible so as to minimize the force necessary for the reversibility, the output η′ should also be maximized. Indeed, this output is a function of the friction coefficient which must thus be minimized. Now, in the course of time and under the action of the contact pressures at the interface between threaded rod and nut, this friction coefficient μ is degraded and does no longer allow to be so reversible.
Therefore and within the framework of a preferred embodiment as shown in FIGS. 1 and 2 , the actuator includes, as springy and/or magnetic restoring means 21 , both a springy and/or magnetic element capable of causing the rotor to rotate in a defined direction so as to restore the control organ O into its reference position and a springy and/or magnetic element 23 capable of acting directly on this control organ O for this purpose.
The peculiarity of the helical systems, and in particular of the screw and nut system 14 , is that they have a output varying according to the helix angle. Therefore, when a high reduction coefficient is sought, which implies a small angle, this results into a low direct output and especially reverse output which are highly penalizing as regards the springy restoring function of the actuator.
The solution as defined in FIG. 3 allows to partly cope with these low outputs. In fact, in this case, the screw and nut system 14 does no longer require an anti-rotation function and the nut 16 , connected to the rotor 4 , describes a helical motion on the fixed threaded rod 17 B, and transmits the translation to the exit shaft 0 through a single bearing.
Furthermore, it has advantageously been devised to distinguish, at least partly, the motion-conversion and reduction functions, by associating with said driving means 5 an independent reversible reduction device 43 .
As can be seen in FIGS. 4 and 5 , such a reversible reduction device can adopt the form of an epicyclical gear 44 through which rotor 4 attacks, according to the embodiment of FIG. 4 , the nut 16 engaged with the threaded rod 17 , the latter being designed with a large pitch and therefore perfectly reversible. In the design according to FIG. 5 is used a system 14 A comprised of a roller 40 and a cam 41 .
In FIGS. 6 to 8 , this reduction device 43 is in the form of a differential gear 45 through which is created a differential rotation speed between, in the case of FIG. 6 , the nut 16 carried by the rotor 4 and a nut 17 A integral in translation and freely rotating of the control organ O.
In the case of FIG. 7 , the differential gear 45 is intercalated between the cam 41 carried by the rotor 4 and the roller 40 integral with the exit shaft 46 of this differential gear 45 . Here too, this exit shaft 46 is integral in translation, while being freely rotating, with the control organ O.
In these various architectures, the use of a differential gear between the two parts performing the conversion of the motion has the advantage of being capable of carry out a significant and always reversible reduction in a small size.
The principle of this differential reduction gear 45 consists in driving, at different, close speeds, both organs allowing performing the motion conversion:
the screw 17 A and the nut 16 in the case of FIG. 6 . The roller 40 and the cam 41 in the case of FIG. 7 .
Obviously, the closer the speeds of both motion-conversion organs, the larger is the reduction achieved through the differential gear.
In the configuration according to the FIG. 8 , the rotor 4 controls the rotation of the first cam 41 as well as, through the differential gear 45 , the second cam 41 A with a reversed profile. The differential speed of these cams 41 and 41 A imparts to the roller 40 , in the form of a pin, an axial displacement which is re-transmitted to the control organ O.
In the latter case, the conversion of the motion is achieved by three different organs: both cams 41 and 41 A of opposite profiles and the pin 40 resting against the two helices under the action of the restoring springs.
The pin 40 is driven by the cam 41 and retained by the other one 41 A, so that it is subjected to a translation and rotational motion, which rotation is different from the speeds of said cams.
The motion of this pin 40 can then be transmitted to the control organ O through a pivot connection, so as to preserve only the translation wanted at the outlet of the actuator.
It is important to note that the motion conversion by two helices has an intrinsic reduction of the movement.
Indeed, since the pin 40 evolves along the two helical profiles corresponding to the cams 41 , 41 A, there is required, in order to induce a given axial displacement, a larger relative rotation of these cams 41 and 41 A in the system as shown in FIG. 8 than that required in the case of a system with one cam as shown in FIG. 7 .
Thus, in the case of FIG. 8 , there is a reduction of movement generated by the differential reduction gear to which is added an additional reduction inherent to the use of two helical profiles.
Moreover, this conversion technique allows to avoid blocking in rotation the roller defined by the pin, this contrary to the traditional helical systems. Hence, it avoids the losses due to friction this type of blocking normally generates and the mechanical output is therefore increased accordingly.
Finally, this particular motion conversion has the following advantages:
a larger motion conversion than that achieved with a traditional system with only one helical profile or screw and nut, a higher output than these same systems.
The design shown in FIG. 8 allows to note that these two concepts of differential drive and conversion with double helix are easily matched and allow achieving an interesting actuator in terms of reduction of motion, output and compactness.
It is clearly stated that the present invention is in no way limited to these various embodiments, whether of the driving means 5 or of the reduction device 43 .
FIGS. 1 and 2 correspond to embodiments of the invention which differ mainly by their respective position-detection device 25 , 25 A.
Thus, according to a first embodiment, this device 25 consists, as shown in FIG. 1 , of magneto-sensitive elements, such as Hall sensors 26 , integrated in a known way known in the stator 3 and designed capable of detecting the magnetic poles of the rotor 4 inside the motor 2 . Thus, knowing the geometry of the latter and thanks to an electronic control unit, the signals delivered by these Hall sensors 26 allow to derive the angular position of the motor 2 and to carry out a control or an adjustment of the position at a pre-set value without using an additional position sensor or encoder.
In the event the linear positioning resolution by using the auto-switching signals as position measure is insufficient for the application involved, there can be used, as a position detection device 25 A, a linear position sensor 27 as shown in FIG. 2 . The linear position is then known with respect to a reference position established by a mechanical stop. Moreover, knowing the linear position as well as the geometry of the actuator, the angular position of the rotor 4 of the motor can be derived and, thus, the switching over of the current supply to the phases can occur, in this case, without using any Hall sensor.
In particular, according to the embodiment shown in this FIG. 2 , the threaded rod 17 defining the control organ O passes through rotor 4 on the side of its end 19 opposite the one 18 acting more particularly as a control organ, in order to co-operate with said position sensor 27 of a contactless electromagnetic type, as described in WO-93.23720.
In particular, this sensor 27 includes a permanent magnet 28 located in the extension of the threaded rod 17 and made integral with the latter at its end 19 . This magnet 28 moves between a stator 29 and a yoke 30 . An analogue Hall sensor 31 is placed in a measuring gap provided for in the yoke 30 . Thus, according to the linear position of the threaded rod 17 , hence of the magnet 28 , the Hall sensor 31 sees variations of magnetic fields in the measuring gap. It then sends a linear position signal.
Obviously, further types of position-detection devices can be contemplated in association with a linear electric actuator according to the invention.
|
A linear actuator includes a brushless polyphase synchronous electric motor having a stator and a rotor. The rotor acts on a control element via a driver which can transform the rotation movement thereof into a linear movement over several rotations. Preferably, the inventive actuator comprises elastic and/or magnetic return device which can systematically return the control element to a reference position when the power supply to the motor is cut. The motor has a position detection device which, together with an electronic control unit, is used for the automatic control and regulation of the position of the rotor and, therefore, the control element.
| 7
|
The present invention relates to a two-stroke engine with external mixture generation in a carburettor, and an associated operating method.
BACKGROUND
Two-stroke engines of conventional construction usually include a so-called crank-chamber scavenging, whereby the sucked-in fuel-air mixture is led first of all into the crank chamber, which receives the crankshaft and is surrounded by the crankcase. There, the fuel-air mixture is supercharged by the piston sliding downwards in the cylinder in the working stroke, and is then transferred, when the piston frees an associated transfer passage in the cylinder wall, to the combustion chamber. In the next stroke, the piston slides upwards and compresses the transferred mixture in the combustion chamber, while at the same time a fresh mixture is sucked into the crank chamber. The terms “up” and “down” refer to an upright cylinder arrangement with the cylinder head located on top.
In a two-stroke spark-ignition engine, ignition of the fuel-air mixture compressed by the piston is effected in the combustion chamber through an active ignition device in the form of a spark plug with associated voltage supply and release electronics, when the piston passes the dead center. The burnt mixture or exhaust gas is released from the combustion chamber at the end of the working stroke through an outlet passage then freed by the piston and is, as a rule, led through an exhaust manifold into the exhaust or muffler section.
Two-stroke engines can be configured for an internal mixture generation with direct injection of the liquid fuel into the combustion chamber or for an external mixture generation in a carburettor. In the carburettor, the liquid fuel is injected into the air flow, which is sucked in or pressed in through a charging device, and atomized. A crank-chamber scavenging is in most cases combined with an external mixture generation.
Usually, a gasoline-oil mixture is supplied as fuel to such two-stroke engines, the addition of oil serving for lubricating the motor. Especially in recent times, it is desired, due to corresponding financial incentives, to replace (regular) gasoline by kerosene, which is normally used as fuel for gas-turbine engines, or also by diesel fuel.
Corresponding attempts to upgrade a two-stroke spark-ignition engine for an operation with diesel or kerosene, are known, for example, from U.S. Pat. No. 5,855,192. For an improved ignition behavior, in particular in the stage of the motor start, a heating of the cylinder head with the help of a glow pencil applied there, which is independent of the spark plug, is provided there. The cylinder head is in this case subjected to a relatively high thermal stress, which generally requires the use of correspondingly high-quality and high-temperature resistant materials and of, for example, ceramic components in the cylinder. Nevertheless, on the whole, the running behavior of motors modified in this manner zierter is not convincing.
SUMMARY
The present invention is, therefore, based on the task to upgrade a two-stroke engine of the above-mentioned type for a supply of kerosene as fuel, by means of as slight and cost-advantageous constructional modifications as possible, without a deterioration of the running behavior and the structural durability. Furthermore, an associated operating method shall be provided.
With regard to the motor, the task is solved according to the present invention by the fact that a suction funnel is arranged upstream of the carburettor on the air-inlet side, an insert being arranged in the area of the inlet port of the suction funnel, said insert tapering first of all continuously in flow direction of the air flow sucked in, in motor operation, and then expanding suddenly.
BRIEF DESCRIPTION OF THE DRAWINGS
An exemplary embodiment of the present invention will be explained in detail in the following by means of a drawing, in which:
FIG. 1 is a longitudinal sectional view through a two-stroke engine (the crank axis lying in the cutting plane);
FIG. 2 is a cross-sectional view through the two-stroke engine according to FIG. 1 (the crank axis being normal to the cutting plane); and
FIG. 3 is a cross-sectional view through an alternative embodiment of a two-stroke engine in accordance with the present invention.
Identical parts are marked with the same reference numbers in the three figures.
DETAILED DESCRIPTION
The present invention is based on the consideration that the heating of the cylinder head by means of a separate glow pencil or the like, known from the state of the art and taken over by the diesel motor, creates more problems than it offers advantages, so that this concept should be discarded. Surprisingly, it turned out that an ignitable fuel-air mixture can also be provided when using kerosene as fuel, namely by installing an insert of the before-mentioned type in the suction funnel of the carburettor, which generates the eddies in the sucked-in air flow and increases the air flow rate through the carburettor.
In other words: Expediently, a suction funnel tapering towards the carburettor inlet is arranged upstream of the carburettor on the air-inlet side. In the area of the inlet port of the suction funnel, preferably an annular insert is arranged, which first of all tapers in flow direction of the air flow sucked in, in motor operation and then expands suddenly.
The insert can be installed, for example, as a retrofit part in a conventional suction funnel. Alternatively, the suction funnel can also include the desired internal outlining from the start. In particular, a correspondingly modified suction funnel can also be manufactured as a single-piece integral component, for example by a casting method.
Due to the Venturi effect of the narrowing cross-section of the flow passage, the sucked-in air flow is first of all accelerated, i.e. its flow speed is increased. At the transition point, where the cross-section expands suddenly and afterwards continuously narrows again towards the carburettor inlet, in accordance with the specified funnel shape, the air flow is—as a consequence of a speed reduction—strongly swirled. It turned out that such a swirl of the air flow before the entry into the carburettor is advantageous, especially with the atomization of kerosene, and results—in particular in combination with a subsequent preheating of the kerosene-air mixture in the crank chamber (see below)—in an improved combustion.
The carburettor is preferably designed as a diaphragm-type carburettor. This has the advantage that the carburettor will function independently of its position and even under strong vibrations. The fuel-air mist generated in this way is advantageously sucked in through an inlet passage when the piston moves upwards in the crank chamber of the two-stroke engine and is supercharged there, when the piston afterwards moves downwards. Expediently, a non-return valve, designed, for example, as a diaphragm valve, is arranged in the inlet passage situated between the crank chamber and the carburettor, preventing a backflow of the fuel-air mixture from the crank chamber in direction of the carburettor during the downward movement of the piston (supercharging stage).
Furthermore, it has turned out that a particularly good running behavior of a two-stroke engine with crank-chamber scavenging can in particular be achieved if the fuel-air mixture is heated in the crank chamber already before entering the combustion chamber—but after having been atomized in the carburettor—up to an appropriate operating temperature, in particular beyond the temperature achievable by means of supercharging.
For this purpose, a heating of the crankcase over a relatively large surface is provided by means of an associated heating device, which is preferably arranged on the outside of the crankcase facing away from the crank chamber. In this way, it is achieved that during motor operation, heat is transferred from the heated outer wall of the crankcase over the inner wall to the fuel-air mixture coming from the carburettor and flowing into the crank chamber.
The thermal stress of the crankcase keeps in this case within well controllable limits, while consistently avoiding an overstressing—caused, for example, by the use of glow pencils or the like—of the cylinder head, which is anyhow stressed already by the combustion processes in the combustion chamber. Due to the relatively long dwelling time of the fuel-air mixture in the crank chamber, in any case as compared with the dwelling time in the combustion chamber prior to ignition, the heating provided now is extremely efficient. In this case, the fuel-air mixture enters the combustion chamber in preheated condition. The additional heating through the compressing process during the upward movement of the piston need not be so strong any more. In this way, excellent ignition properties are guaranteed, in particular when using kerosene as fuel.
In an embodiment according to the present invention, the heating device is primarily designed as a cold-start aid and includes a number of electric heating elements. For a good heat transfer to the crankcase, these heating elements, which are preferably designed as heating rods or heating mats, advantageously abut directly on the outside of the crankcase, i.e. they are in close thermal contact therewith. Their location on the outside has the advantage that the electric supply lines need not be passed through the crankcase, and that the heating elements are not directly exposed to the chemically aggressive fuel-air mixture. The heating elements are supplied with heating current, above all in case of a cold start of the motor, by an external current source, to warm up the fuel-air mixture in this manner when it flows through the crank chamber. The number of heating elements and their heating power depend in particular on the volume of the crank chamber surrounded by the crankcase and on the warming-up time desired and necessary for reaching of certain temperature level. To make a kerosene-air mixture ignitable for the cold start, the temperature of the crankcase on the inner wall facing towards the mixture should amount, for example, to approximately 80° C. to 90° C.
In an alternative embodiment according to the present invention, the crankcase is advantageously of a double-walled design, the inner and outer walls of the crankcase enclosing a space which can be filled with a liquid. For operating the motor, in particular during the starting process, the space is filled with a liquid, which is then heated by means of a suitable electric heating system, for example, by means of heating rods arranged in the space or outside the outer wall.
To avoid having to operate the electric heating system permanently and to make it possible instead to switch off the motor after the starting process and possibly after a certain minimum running time (warming-up stage) and to disconnect it from the heating-current source, it is advantageously provided to heat the crankcase and thus, the crank chamber, by the hot residues of combustion or exhaust gases liberated during operation. For this purpose, at the combustion-chamber outlet, an exhaust manifold running into a downstream exhaust or muffler system is expediently led around or along the crankcase or possibly also integrated into the crankcase, in such a way that the crankcase is heated by the exhaust manifold through heat radiation and/or through heat conduction. For a close thermal contact, the exhaust manifold advantageously abuts, at least in a partial section, on the outside of the crankcase; preferably, the exhaust manifold is connected there with the crankcase, for example, by welding or brazing. Instead of a substance-locking connection or in addition thereto, a frictional and/or positive-locking connection can, however, also be provided, e.g. by screwing, rivetting, etc.
Alternatively, instead of an exhaust manifold whose end facing away from the combustion-chamber outlet runs into a muffler pot, a muffler itself can be led around the crankcase in the above-described manner.
In an another embodiment according to the present invention, a thermal insulation is provided between the crankcase—which is advantageously heated by a heating device—and the carburettor, so that there is, if possible, no heat transfer or only little heat transfer from the crankcase to the carburettor housing and the carburettor is kept as cool as possible. Expediently, for this purpose, the valve housing located between the crankcase and the carburettor housing and surrounding the inlet passage for the atomized fuel-air mixture with the non-return valve arranged therein, is made of a heat-insulating material with a considerably lower thermal conductivity than the material of the crankcase, in particular of a heat-resistant synthetic material with high mechanical and chemical stress-bearing capacity, e.g. polyphenylene sulfide (PPS) or a similar synthetic material. Furthermore, the exhaust manifold is preferably arranged at a sufficient distance from the valve housing, so that there will be no significant heat transfer through heat radiation.
In an embodiment according to the present invention, the two-stroke engine is designed as a spark-ignition engine, i.e. it includes an electric ignition system with a spark plug integrated in the cylinder head for ignition—controlled independently of the piston position—of the fuel-air mixture compressed by the piston. It would also be imaginable to design the two-stroke engine alternatively as a self-ignition motor with a glow plug permanently glowing in operation, for example with a wire coil coated with platinum iridium.
Regarding the method, the before-mentioned task is solved by atomizing kerosene or diesel fuel in a carburettor and leading the kerosene-air mixture or diesel fuel-air mixture generated in this way into the combustion chamber of the two-stroke engine, an air flow supplied to the carburettor being led, before entering the carburettor, in particular before entering the carburettor, through a section of a flow passage which first of all tapers continuously and then expands suddenly.
By “kerosene”, one understands in the present case in particular a fuel made of the light middle distillate of crude-oil refining, namely a light petroleum, otherwise usually applied in aviation for operating gas-turbine engines (aviation turbines). The bubble-point curve of kerosene, which is as a rule widely stretched and flat, lies between the curve of heavy naphta and diesel fuel. Suitable kerosene types are sold, for example, under the trade names JP-1 (Jet Propellant-1) or JET A-1 (former designation: JP-1A) or JP-8 or JET B or TS-1. Kerosene of type JET A-1 is particularly widely used and easy to obtain. For the purpose of lubrication of the motor, a lubricating oil and/or other additives, for example 4% synthetic two-stroke-oil, can be added to the kerosene.
Alternatively to kerosene, a diesel fuel may also be supplied to the two-stroke engine described here.
Preferably, the method is applied in a two-stroke engine with crank-chamber scavenging, the kerosene-air mixture or diesel fuel-air mixture generated in the carburettor being led through the crank chamber into the combustion chamber. Advantageously, the mixture is preheated by means of a heating device when flowing through the crank chamber and ignited by means of an active ignition device after having entered the combustion chamber.
In an embodiment of a method according to the present invention, the crankcase is heated by an electric heating device during a starting process, in particular during a cold start of the motor. After a certain start-up time, advantageously the electric heating device is switched off and the crankcase is heated by an exhaust manifold or muffler, which is connected to the combustion-chamber outlet of the two-stroke engine and through which hot combustion exhaust gases flow, through heat conduction and/or through heat radiation.
Due to the before-described measures, the kerosene-driven two-stroke engine shows a similarly good and “smooth” running as a two-stroke gasoline engine. The better combustion makes the motor run more coolly, fuel consumption is reduced. The mean temperature in the area of the cylinder-head housing will then amount, for example, to only approximately 160° C. to 190° C., as compared with approx. 220° C. of a convention gasoline engine with the same volumetric displacement. It is not necessary either to choose a higher compression ratio than that of gasoline engines. The compression ratio, i.e. the ratio between the total space of the combustion chamber prior to compression and the remaining space after compression can, on the contrary, be somewhat smaller, thanks to the described measures, than that of a gasoline-driven motor, amounting, for example, to only 8:1 to 10:1. This results in a reduction of the vibration level and thus in a longer lifetime of the crankshaft and the associated ball bearings or needle bearings.
The constructional modifications typically necessary for kerosene operation do not affect the motor section properly speaking—cylinder, piston, crankcase—or affect them to an insignificant degree only. Rather are they limited predominantly to peripheral components—exhaust manifold, valve housing, carburettor, and suction funnel. Therefore, they can be retrofitted relatively easily even in existing motors of conventional design.
The two-stroke engine 2 represented in FIG. 1 and FIG. 2 is of a predominantly conventional design and serves, for example, for driving model airplanes or also chain saws, lawn mowers, etc. With a corresponding volumetric displacement, it could, however, also be provided, for example, for driving a passenger aircraft or a passenger car or a motorcycle or the like.
The two-stroke engine 2 includes a piston 8 sliding in a cylinder 4 and driven by periodical combustion processes in the combustion chamber 6 . A connecting rod 10 transmits the linear motion of the piston 8 to the crankshaft 12 and transforms it into a rotary motion. The crankshaft 12 is supported in a crankcase 14 and is continued on the drive side by a drive shaft 16 , which can be connected to the drivetrain of an engine to be driven or can be equipped with a propeller. The spatial area closed on top by the piston 8 , between the crankshaft 12 and the crankcase 14 , is called crank chamber 18 . The crank chamber 18 is connected by means of a transfer passage 22 , which is externally limited by the cylinder housing 20 , with the combustion chamber 6 , the transfer port 24 running into the combustion chamber 6 being freed substantially only in the lower dead-center position of the piston 8 . In this piston position, the outlet passage 26 connected to the combustion chamber 6 (see FIG. 2 ) is also freed. In the cylinder head 28 , an electric spark plug 30 is arranged.
On the side of the crankcase 14 which faces away from the drive shaft 16 , a valve housing 32 , a carburettor 34 and a suction funnel 36 are adjacent. Through the suction funnel 36 , ambient air is sucked in during motor operation and fed to the carburettor 34 . In the carburettor 34 , designed as a diaphragm carburettor, liquid fuel fed by a supply line (not shown) is injected into the air flow sucked in, and atomized.
During the suction stage, through the suction effect of the piston 8 sliding upwards, the fuel-air mixture passes through the inlet passage 38 surrounded by the valve housing 32 and enters the crank chamber 18 . During the following downward movement of the piston 8 , the mixture is supercharged in the crank chamber 18 , a non-return valve 40 arranged in the inlet passage 38 and designed as a diaphragm valve preventing a backflow to the carburettor 34 . At the end of the compression stage, the fuel-air mixture flows through the transfer passage 22 into the combustion chamber 6 , at the same time pressing the residues of combustion (exhaust gases), that have remained from the previous combustion process, through the outlet passage 26 out of the combustion chamber 6 . During the following upward movement of the piston 8 , the mixture is first of all compressed in the combustion chamber 6 and finally ignited by an ignition spark at the spark plug 30 ; the working stroke starts (of course, the above-described processes are partially running in parallel).
The two-stroke engine 2 has been upgraded through a number of constructional measures for a kerosene operation:
In particular, the exhaust manifold 42 connected to outlet passage 26 and running at the other end, for example, into the resonance pot of a resonance muffler (not shown) is led in the manner of an arc around the lower part of the motor block. The plane in which the arc lies, is in the exemplary embodiment substantially normal to the crank axis or drive axis (see FIG. 2 ). A lower partial section of the exhaust manifold 42 abuts on the outer wall 43 of the crankcase 14 and is welded to it there. Therefore, an effective heat transfer takes place during motor operation, from the exhaust manifold 42 heated from inside through the hot exhaust gases to the crankcase 14 and thus finally also to the fuel-air mixture coming from the carburettor 34 and flowing into the crank chamber 18 , said mixture being, therefore, preheated.
In an alternative variant, shown in FIG. 3 , no exhaust-manifold section or only a very short exhaust-manifold section is provided. In this case, the muffler 60 or muffler pot is adjacent to the outlet passage 26 and follows in the manner of an arc the outline of the cylinder 4 and of the crankcase 14 , thus obtaining the desired warning-up function.
Furthermore, for a cold start of the motor, an electric heating of the crankcase 14 by means of several electric heating elements 44 , here in the form of heating rods, fixed on the outside, possibly inserted in corresponding recesses and abutting on the housing wall, are provided. The electric connection lines 45 of the heating elements 44 can be connected for this purpose to an external heating-current source, not shown here. In an exemplary embodiment, the rod-shaped heating elements 44 are substantially arranged on the underside of the crankcase 14 , oriented parallel to the drive shaft 16 and uniformly distributed around the crankcase 14 , in order to enable a uniform heating of the interior space, i.e. the crank chamber 18 . The concrete execution and arrangement may, however, differ therefrom.
A heating of the cylinder head through additional glow pencils or the like is advantageously not provided. A preheating of the fuel fed to the carburettor 34 is not necessary and advantageously not provided either.
Contrary to the usually metallic crankcase 14 and the also metallic exhaust manifold 42 , the valve housing 32 adjacent to the crankcase 14 and connected on the other side with the carburettor housing of the carburettor 34 is made of a material with as low a thermal conductivity as possible, in the present case, e.g., of a heat-resistant, dimensionally stable high-performance plastic, which is resistant to the kerosene-air mixture flowing past it inside. A suitable material is, for example, the glass-fibre reinforced synthetic material based on polyphenylene sulfide, known by the trade name Ryton R-4 (registered trademark of Chevron Phillips Chemical Company LP). Other materials fulfilling the above-mentioned characteristics, can be also used. Expediently, the valve housing 32 is screwed on one side to the crankcase 14 and on the other side, to the carburettor housing.
Finally, the suction funnel 36 arranged upstream of the carburettor 34 on the air suction side has been modified as compared with the variants in use so far, in that an insert 48 narrowing the cross-section and generating eddies is arranged in its wide inlet port 46 . Through the annular insert 48 , the free cross-section for the flow of the sucked-in air narrows first of all continuously and monotonously in flow direction 50 and then, at the narrowest place, it preferably expands suddenly (discontinuously). Depending on the motor type and the individual case, the diameter of the narrow passage 52 of the insert 48 is preferably 55% to 75%, particularly preferably 60% to 66% of the diameter of the inlet port 48 . Viewed in flow direction 50 , the diameter suddenly enlarges again, directly behind the narrow passage 52 , to almost the value it had in the area of the inlet port 48 (100%) and finally decreases continuously in direction of the carburettor inlet. Such a “funnel-in-funnel” arrangement serves for increasing the pressure of the oxygen share flowing into the carburettor 34 , due to the induced eddies, and has turned out to particularly advantageous especially with a kerosene atomization.
In particular when combining the above-described measures, the two-stroke engine is upgraded for an operation with kerosene or also with diesel fuel, without an expensive new construction and new design of the central components cylinder, piston and crankcase or of the ignition system, and that for all usual volumetric displacements of, for example, 30 cm 3 or less up to 700 cm 3 or more. Of course, the above-described concept can also be realized in multicylinder engines, e.g. in multicylinder straight-type engines, V-type engines, flat engines or radial-type engines. Depending on the position of the outlet passages and depending on the “accessibility” of the crankcase, the course of the exhaust manifold(s) may be varied. Possibly, a single exhaust manifold can then be provided for heating several crankcase sections allocated to the individual cylinders.
The present invention is not limited to embodiments described herein; reference should be had to the appended claims, and such modifications are evident for the person skilled in the art in the light of the above description.
LIST OF REFERENCE NUMBERS
2 Two-stroke engine
4 Cylinder
6 Combustion chamber
8 Piston
10 Connecting rod
12 Crankshaft
14 Crankcase
16 Drive shaft
18 Crank chamber
20 Cylinder housing
22 Transfer passage
24 Transfer port
26 Outlet passage
28 Cylinder head
30 Spark plug
32 Valve housing
34 Carburettor
36 Suction funnel
38 Inlet passage
40 Non-return valve
42 Exhaust manifold
43 Outer wall
44 Heating element
45 Connection line
46 Inlet port
48 Insert
50 Flow direction
52 Narrow passage
60 Muffler
|
A two-stroke engine with external fuel mixture generation in a carburetor. The engine including a suction funnel having an interior disposed upstream of the carburetor. The engine further includes a tapered insert having a narrow end and a wide end disposed in an area of an inlet port of the suction funnel. The insert at least partially defines the interior of the suction funnel, and the insert tapers in a flow direction of air flow from the wide end to the narrow end. Accordingly, a diameter of the interior of the suction funnel adjacent to the narrow end of the insert is substantially larger when compared to the narrow end of the insert.
| 5
|
RELATED APPLICATIONS
This application is a continuation of prior U.S. patent application Ser. No. 09/288,003 filed Apr. 6, 1999, now U.S. Pat. No. 6,267,400 issued Jul. 31, 2001, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of bicycle suspensions. More particularly, the invention relates to a damping enhancement system for a bicycle.
2. Description of the Related Art
For many years bicycles were constructed using exclusively rigid frame designs. These conventional bicycles relied on air-pressurized tires and a small amount of natural flexibility in the frame and front forks to absorb the bumps of the road and trail. This level of shock absorption was generally considered acceptable for bicycles which were ridden primarily on flat, well maintained roads. However, as “off-road” biking became more popular with the advent of All Terrain Bicycles (“ATBs”), improved shock absorption systems were needed to improve the smoothness of the ride over harsh terrain. As a result, new shock absorbing bicycle suspensions were developed.
Two such suspension systems are illustrated in FIGS. 1 and 2. These two rear suspension designs are described in detail in Leitner, U.S. Pat. No. 5,678,837, and Leitner, U.S. Pat. No. 5,509,679, which are assigned to the assignee of the present application. Briefly, FIG. 1 illustrates a telescoping shock absorber 110 rigidly attached to the upper arm members 103 of the bicycle on one end and pivotally attached to the bicycle seat tube 120 at the other end (point 106 ). FIG. 2 employs another embodiment wherein a lever 205 is pivotally attached to the upper arm members 203 and the shock absorber 210 is pivotally attached to the lever 205 at an intermediate position 204 between the ends of the lever 205 .
There are several problems associated with the conventional shock absorbers employed in the foregoing rear suspension systems. One problem is that conventional shock absorbers are configured with a fixed damping rate. As such, the shock absorber can either be set “soft” for better wheel compliance to the terrain or “stiff” to minimize movement during aggressive pedaling of the rider. However, there is no mechanism in the prior art which provides for automatic adjustment of the shock absorber setting based on different terrain and/or pedaling conditions.
A second, related problem with the prior art is that conventional shock absorbers are only capable of reacting to the relative movement between the bicycle chassis and the wheel. In other words, the shock absorber itself has no way of differentiating between forces caused by the upward movement of the wheel (i.e., due to contact with the terrain) and forces caused by the downward movement of the chassis (i.e., due to movement of the rider's mass).
Thus, most shock absorbers are configured somewhere in between the “soft” and “stiff” settings (i.e., at an intermediate setting). Using a static, intermediate setting in this manner means that the “ideal” damper setting—i.e., the perfect level of stiffness for a given set of conditions—will never be fully realized. For example, a rider, when pedaling hard for maximum power and efficiency, prefers a rigid suspension whereby human energy output is vectored directly to the rotation of the rear wheel. By contrast, a rider prefers a softer suspension when riding over harsh terrain. A softer suspension setting improves the compliance of the wheel to the terrain which, in turn, improves the control by the rider.
Accordingly, what is needed is a damping system which will dynamically adjust to changes in terrain and/or pedaling conditions. What is also needed is a damping system which will provide to a “stiff” damping rate to control rider-induced suspension movement and a “soft” damping rate to absorb forces from the terrain. Finally, what is needed is a damping system which will differentiate between upward forces produced by the contact of the wheel with the terrain and downward forces produced by the movement of the rider's mass.
SUMMARY OF THE INVENTION
A bicycle shock absorber for differentiating between rider-induced forces and terrain-induced forces comprising: a first fluid chamber having fluid contained therein; a piston for compressing the fluid within the fluid chamber; a second fluid chamber coupled to the first fluid chamber by a fluid communication hose; and an inertial valve disposed within the second fluid chamber, the inertial valve opening in response to terrain-induced forces and providing communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber; and the inertial valve not opening in response to rider-induced forces and preventing communication of the fluid compressed by the piston from the first fluid chamber to the second fluid chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention can be obtained from the following detailed description in conjunction with the following drawings, in which:
FIG. 1 illustrates a prior art rear suspension configuration for a bicycle.
FIG. 2 illustrates a prior art rear suspension configuration for a bicycle.
FIG. 3 illustrates one embodiment of the present invention.
FIG. 4 illustrates an embodiment of the present invention reacting to a rider-induced force.
FIG. 5 illustrates an embodiment of the present invention reacting to a terrain-induced force.
FIG. 6 illustrates the fluid refill mechanism of an embodiment of the present invention.
FIG. 7 illustrates another embodiment of the present invention.
FIG. 8 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted directly to an upper arm member and the remote tube is connected to an upper arm member of a bicycle. An angled position of the remote tube is shown in phantom.
FIG. 9 is an enlarced schematic view of an embodiment of the present invention wherein the primary tube is mounted directly to an upper arm member and the remote tube and the primary tube are a single unit. An angled position of the remote tube is shown in phantom.
FIG. 10 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted to a lever and the remote tube is connected to an under arm member of a bicycle. An angled position of the remote tube is shown in phantom.
FIG. 11 is an enlarged schematic view of an embodiment of the present invention wherein the primary tube is mounted to a lever and the remote tube and the primary tube are a single unit. An angled position of the remote tube is shown in phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A damping enhancement system is described which differentiates between upward forces produced by the contact of the bicycle wheel with the terrain and downward forces produced by the movement of the rider's mass. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one of ordinary skill in the art that the present invention may be practiced without some of these specific details. In other instances, certain well-known structures are illustrated and described in limited detail to avoid obscuring the underlying principles of the present invention.
An Embodiment of the Damper Enhancement System
One embodiment of the present damper enhancement system is illustrated in FIG. 3 . The apparatus is comprised generally of a primary tube 302 and a remote tube 304 coupled via a connector hose 306 .
The damper enhancement system described hereinafter may be coupled to a bicycle in the same manner as contemporary shock absorbers (i.e., such as those illustrated in FIGS. 1 and 2 ). For example, the damper enhancement system may be coupled to a bicycle as illustrate in FIG. 1 wherein the upper mount 318 is pivotally coupled to the seat tube at point 106 and the lower mount 342 is fixedly coupled to the upper arm member 103 . Moreover, the damper enhancement system may be coupled to a bicycle as illustrated in FIG. 2 wherein the upper mount 318 is pivotally coupled to the seat tube at point 206 and the lower mount 342 is fixedly coupled to a point 204 on lever 211 . These two constructions are illustrated in FIGS. 8-9 and FIGS. 10-11. respectively.
In addition, depending on the particular embodiment of the damper enhancement system, the connector hose may be of varying lengths and made from varying types of material. For example, the connector hose 306 may be short and comprised of metal. In this case, the primary tube 302 and the remote tube 304 will be closely coupled together—possibly in a single unit. Such a construction is illustrated in FIG. 9 and FIG. 11 . By contrast, the connector hose may be long and comprised of a flexible material. In this case, the remote tube 304 may be separated from the primary tube 302 and may be independently connected to the bicycle (e.g., the remote tube may be connected to one of the wheel members such as upper arm member 103 in FIG. 1 ). FIG. 8 and FIG. 10 illustrate such a construction, wherein the primary tube 302 is coupled to upper arm member 103 and the remote tube 304 is connected to the upper arm member 103 by a connector. Regardless of how the remote tube 304 is situated in relation to the primary tube 302 , however, the underlying principles of the present invention will remain the same.
A piston 308 on the lower end of a piston rod 310 divides the inside of the primary tube 302 into and upper fluid chamber 312 and a lower fluid chamber 314 which are both filled with a viscous fluid such as oil. The piston rod 310 is sealed through the cap with oil seals 316 and an upper mount 318 connects the piston to the chassis or sprung weight of the bicycle (e.g., to the seat tube). A lower mount 342 connects the primary tube 302 to the rear wheel of the bicycle via one or more wheel members (e.g., upper arm members 103 in FIG. 1 or lever 205 of FIG. 2 ). Longitudinally extending passages 320 in the piston 308 provide for limited fluid communication between the upper fluid chamber 312 and lower fluid chamber 314 .
An inertial valve 322 which is slightly biased by a lightweight spring 324 moves within a chamber 326 of the remote tube 304 . The lightweight spring 324 is illustrated in a fully extended state and, as such, the inertial valve 322 is illustrated at one endmost position within its full range of motion. In this position, fluid flow from the primary tube 302 to the remote tube 304 via the connector hose 306 is blocked or reduced. By contrast, when the lightweight spring 324 is in a fully compressed state, the inertial valve resides beneath the interface between the remote tube 304 and the connector hose 306 . Accordingly, in this position, fluid flow from the primary tube 302 to the remote tube 304 through the connector hose 306 is enabled. In one embodiment, the inertial valve 322 is composed of a dense, heavy metal such as brass.
Disposed within the body of the inertial valve 322 is a fluid return chamber 336 , a first fluid return port 337 which couples the return chamber 336 to the connector hose 306 , and a second fluid return port 339 which couples the return chamber 336 to remote fluid chamber 332 . A fluid return element 338 located within the fluid return chamber 336 is biased by another lightweight spring 340 (hereinafter referred to as a “fluid return spring”). In FIG. 3 the fluid return spring 340 is illustrated in its fully extended position. In this position, the fluid return element 338 separates (i.e., decouples) the fluid return chamber 336 from the fluid return port 337 . By contrast, when the fluid return spring 340 is in its fully compressed position, the fluid return element 338 no longer separates the fluid return chamber 336 from the fluid return port 337 . Thus, in this position, fluid flow from the fluid return chamber 336 to the connector hose 306 is enabled. The operation of the inertial valve 322 and the fluid return mechanism will be described in detail below.
The remaining portion of the remote tube 304 includes a floating piston 328 which separates a gas chamber 330 and a fluid chamber 332 . In one embodiment of the present invention, the gas chamber 330 is pressurized with Nitrogen (e.g., at 150 p.s.i.) and the fluid chamber 332 is filled with oil. An air valve 334 at one end of the remote tube 322 allows for the gas chamber 330 pressure to be increased or decreased as required.
The operation of the damping enhancement system will be described first with respect to downward forces produced by the movement of the rider (and the mass of the bicycle frame) and then with respect to forces produced by the impact between the wheel and the terrain.
1. Forces Produced by the Rider
A rider-induced force is illustrated in FIG. 4, forcing the piston arm 310 in the direction of the lower fluid chamber 314 . In order for the piston 308 to move into fluid chamber 314 in response to this force, fluid (e.g., oil) contained within the fluid chamber 314 must be displaced. This is due to the fact that fluids such as oil are not compressible. If lightweight spring 324 is in a fully extended state as shown in FIG. 4, the inertial valve 322 will be “closed” (i.e., will block or reduce the flow of fluid from lower fluid chamber 314 through the connector hose 306 into the remote fluid chamber 332 ). Although the entire apparatus will tend to move in a downward direction in response to the rider-induced force, the inertial valve 322 will remain in the nested position shown in FIG. 4 (i.e., it is situated as far towards the top of chamber 326 as possible). Accordingly, because the fluid in fluid chamber 314 has no where to flow in response to the force, the piston 308 will not move down into fluid chamber 314 to any significant extent. As a result, a “stiff” damping rate will be produced in response to rider-induced forces (i.e., forces originating through piston rod 310 ).
2. Forces Produced by the Terrain
As illustrated in FIG. 5, the damping enhancement system will respond in a different manner to forces originating from the terrain and transmitted through the bicycle wheel (hereinafter “terrain-induced forces”). In response to this type of force, the inertial valve 322 will move downward into chamber 326 as illustrated and will thereby allow fluid to flow from lower chamber 314 into remote chamber 332 via connector hose 306 . The reason for this is that the entire apparatus will initially move in the direction of the terrain-induced force while the inertial valve 322 will tend to remain stationary because it is comprised of a dense, heavy material (e.g., such as brass). Thus, the primary tube 302 and the remote tube 304 will both move in a generally upward direction and, relative to this motion, the inertial valve 322 will move downward into chamber 326 and compress the lightweight spring 324 . As illustrated in FIG. 5 this is the inertial valve's “open” position because it couples lower fluid chamber 314 to remote fluid chamber 332 (via connector hose 306 ).
Once the interface between connector hose 306 and remote fluid chamber 332 is unobstructed, fluid from lower fluid chamber 314 will flow across connector hose 306 into remote fluid chamber 332 in response to the downward force of piston 308 (i.e., the fluid can now be displaced). As remote fluid chamber 314 accepts additional fluid as described, floating piston 328 will move towards gas chamber 330 (in an upward direction in FIG. 5 ), thereby compressing the gas in gas chamber 330 . The end result, will be a “softer” damping rate in response to terrain-induced forces (i.e., forces originating from the wheels of the bicycle).
Once the inertial valve moves into an “open” position as described above, it will eventually need to move back into a “closed” position so that a stiff damping rate can once again be available for rider-induced forces. Thus, lightweight spring 324 will tend to move the inertial valve 322 back into its closed position. In addition, the return spring surrounding primary tube 302 (not shown) will pull piston rod 310 and piston 308 in an upward direction out of lower fluid chamber 314 . In response to the motion of piston 308 and to the compressed gas in gas chamber 330 , fluid will tend to flow from remote fluid chamber 332 back to lower fluid chamber 314 (across connector hose 306 ).
To allow fluid to flow in this direction even when inertial valve 322 is in a closed position, inertial valve 322 (as described above) includes the fluid return elements described above. Thus, as illustrated in FIG. 6, in response to pressurized gas in gas chamber 330 , fluid in remote fluid chamber 332 will force fluid return element 338 downward into fluid return chamber 336 (against the force of the fluid return spring 340 ). Once fluid return element 338 has been forced down below fluid return port 337 , fluid will flow from remote fluid chamber 332 through fluid return port 339 , fluid return chamber 336 , fluid return port 337 , connector hose 306 , and finally back into lower fluid chamber 314 . This will occur until the pressure in remote fluid chamber 336 is low enough so that fluid return element 338 can be moved back into a “closed” position (i.e., when the force of fluid return spring 340 is greater than the force created by the fluid pressure).
The sensitivity of inertial valve 322 may be adjusted by changing the angle with which it is positioned in relation to the terrain-induced force. For example, in FIG. 5, the inertial valve 322 is positioned such that it's movement in chamber 326 is parallel (and in the opposite direction from) to the terrain-induced force. This positioning produces the greatest sensitivity from the inertial valve 322 because the entire terrain-induced force vector is applied to the damper enhancement system in the exact opposite direction of the inertial valve's 322 line of movement.
By contrast, if the remote tube containing the inertial valve 322 were positioned at, for example, a 45° angle from the position shown in FIG. 5 the inertial valve's 322 sensitivity would be decreased by approximately one half because only one half of the terrain-induced force vector would be acting to move the damper enhancement system in the opposite direction of the valve's line of motion. Thus, twice the terrain-induced force would be required to trigger the same response from the inertial valve 322 in this angled configuration. FIGS. 8-11 illustrate the remote tube 304 positioned at an angle from the primary tube 302 (shown in phantom). With such a construction, the sensitivity of the inertial valve 322 may be adjusted as described immediately above.
Thus, in one embodiment of the damper enhancement system the angle of the remote tube 304 in which the inertial valve 322 resides is manually adjustable to change the inertial valve 322 sensitivity. This embodiment may further include a sensitivity knob or dial for adjusting the angle of the remote tube 304 . The sensitivity knob may have a range of different sensitivity levels disposed thereon for indicating the particular level of sensitivity to which the damper apparatus is set. In one embodiment the sensitivity knob may be rotatably coupled to the bicycle frame separately from the remote tube, and may be cooperatively mated with the remote tube (e.g., with a set of gears). Numerous different configurations of the sensitivity knob and the remote tube 304 are possible within the scope of the underlying invention. The connector hose 306 of this embodiment is made from a flexible material such that the remote tube 304 can be adjusted while the primary tube remains in a static position.
Another embodiment of the damper enhancement system is illustrated in FIG. 7 . Like the previous embodiment, this embodiment includes a primary fluid chamber 702 and a remote fluid chamber 704 . A piston 706 coupled to a piston shaft 708 moves within the primary fluid chamber 702 . The primary fluid chamber 702 is coupled to the remote fluid chamber via an inlet port 714 (which transmits fluid from the primary fluid chamber 702 to the remote fluid chamber 704 ) and a separate refill port 716 (which transmits fluid from the remote fluid chamber 704 to the primary fluid chamber 702 ).
An inertial valve 710 biased by a lightweight spring 712 resides in the remote fluid chamber 704 . A floating piston 720 separates the remote fluid chamber from a gas chamber 718 . In response to terrain-induced forces (represented by force vector 735 ), the inertial valve, due to its mass, will compress the lightweight spring 712 and allow fluid to flow from primary fluid chamber 702 to remote fluid chamber 704 over inlet port 714 . This will cause floating piston 720 to compress gas within gas chamber 718 .
After inertial valve 710 has been repositioned to it's “closed” position by lightweight spring 712 , fluid in remote fluid chamber 704 will force fluid refill element 722 open (i.e., will cause fluid refill spring 724 to compress). Thus, fluid will be transmitted from remote fluid chamber 704 to primary fluid chamber 702 across refill port 716 until the pressure of the fluid in remote fluid chamber is no longer enough to keep fluid refill element 722 open. Thus, the primary difference between this embodiment and the previous embodiment is that this embodiment employs a separate refill port 716 rather than configuring a refill port within the inertial valve itself.
|
A bicycle shock absorber for differentiating between rider-induced forces and terrain-induced forces comprising: a first fluid chamber having fluid contained therein; a piston for compressing the fluid within the fluid chamber; a second fluid chamber coupled to the first fluid chamber by a fluid communication hose; and an inertial valve disposed within the second fluid chamber, the inertial valve opening in response to terrain-induced forces and providing communication of fluid compressed by the piston from the first fluid chamber to the second fluid chamber; and the inertial valve not opening in response to rider-induced forces and preventing communication of the fluid compressed by the piston from the first fluid chamber to the second fluid chamber.
| 1
|
BACKGROUND OF THE INVENTION
This invention relates to containers and has particular reference to containers for use on pallets. The conventional ways of shipping material, which is fluid by nature, either liquid or powder, normally comprise the use of small drums of 25 liters or 150 liters size or requires the use of bulk tankers capable of handling large volumes of liquid or other fluids. The bulk tankers are normally returned to base for refilling or reloading whereas the small containers are often regarded as disposable. Because of the cost of handling there is a requirement to increase the size of the small bulk containers without doing away with the advantages of the use of disposable containers. The present invention has particular application to containers capable of carrying loads of the order of one ton and being used on a standard sized pallet.
In British Patent Specification No. 1 400 414 there is described the use of a container of approximately the same size as that used for the present invention which comprises a double-skinned container with a wooden reinforcing strut located vertically in the centre of each face of the container between the skins. The skins are both structural members and the fluids are retained inside by means of a separate bag which is not shown specifically in the drawings of the patent specification. It has been found that there are differences in using containers of the type described in the above mentioned British patent for liquids as opposed to powders. By their very nature liquids are more mobile than dry powders and the container may be regarded as being more "active" during transport. The present applicants have found that although such a container is suitable for transporting dry powders it is necessary, when transporting liquids, to provide a restraining collar to support the container in use. Otherwise it has been found that the container can fail during transport. Experiments have illustrated that a restraining band of the order of 21/2 cm 2 of steel is sufficient to have strength to carry out the necessary restraining effect. It has also been found desirable to provide a 21/2 cm 2 rim around the pallet on which the container sits. Unfortunately the use of such restraining collars has two disadvantages. The first is the economic disadvantage in providing the collar, both in material costs, fabrication costs and handling costs. The second, perhaps more serious, is the loss of volume associated with the loss of the exterior 21/2 cm thick zone which is occupied by the collars and which could otherwise be useful for the transport of liquid. The loss of volume associated with the use of 21/2 cm 2 collars on a pallet 1 m 2 is 7 or 8%.
In British Patent Specification No. 1 467 884 there is described a modification of the invention described in British Patent Specification No. 1 400 414, in which the upright struts are secured to the outer skin by means of a turn buckle. Again, the invention described in British Patent Specification No. 1 467 884 requires the use of two structural skins which are separated by the upright struts.
To the best of the Applicant's belief there are no known containers for liquids capable of being used on a standard ISO pallet (1 m 2 ) which are formed basically of a fibre or cardboard exterior having a simple plastics liner. There are many proposals for using cardboard boxes to contain materials, and proposals have been made, see UK Patent Specification No. 2 024/1913, to use wires to strengthen cardboard boxes such as hat boxes or drawers. However, such systems would not be useful for semi-bulk containers of a size intended to be used on an industrial pallet.
In UK Patent Specification No. 883 762 there is described a reinforced fibreboard container being formed of inner and outer fibreboard layers, but there are no provisions to permit the box to withstand the pressures found in semi-bulk containers for liquids.
UK Patent Specification No. 1 279 232 is concerned with composite boxes having a capacity in the region 100-200 gallons, but proposes the use of expensively machined corner portions to withstand the pressures attendant upon the use of fibreboard for the external shell of the container.
In UK Patent Specification No. 1 295 831 a stillage bin is provided in which internal pressures are resisted by an external framework provided around the container.
UK Patent Specification No. 1 297 915 proposes a container in which wooden posts are used in the corners to support the corners of the container.
UK Patent Specification No. 1 378 507 proposes a container in which rigid reinforcing elements are secured to the faces of the panels in a horizontal plane.
SUMMARY OF THE INVENTION
By the present invention there is provided a container for fluids comprising a fluid-tight inner bag, an outer skin of polygonal shape and a top and base formed of flap extensions of the walls of the skin, a plurality of support struts, each located in an upright position on the inside face of one side wall, each wall being provided with at least one rigid support strut, and the rigid support struts being secured to their respective side walls, upper tension means to interconnect the upper ends of the support struts so as substantially to prevent the ends moving apart and lower tension means to interconnect the lower ends of the support struts so as substantially to prevent the ends moving apart.
Preferably, the upper and lower tension means are located between the ends of the inner bag and the flap extensions of the walls.
Preferably there are four walls with four rigid support struts. Preferably there is one rigid support member per wall. There may be two or more rigid supports per wall. Each strut may be located centrally in a wall when the number of struts is the same as the number of walls.
Each tension means may include a pair of support struts interconnecting opposing faces. Alternatively there may be provided a rectangular tension means so as to interconnect adjacent posts.
The outer skin is preferably formed of cardboard or other fibre board and is preferably formed of corrugated cardboard. Particularly suitable material is Triwall corrugated cardboard which comprises three corrugated layers superimposed one directly on the other.
The upper and lower tension means may be steel straps in engagement with the support struts. The steel straps preferably have integral tags to engage the support struts between the support struts and the walls of the container. The support struts may be formed of wood. They may be connected to the walls of the box by bolts which may be passed through holes in the walls of the box and provided with reinforcing plates externally of the fibreboard walls. Each support member may have two bolts located uniformly along its length intermediate the ends thereof.
The base of the fluid-tight bag may be secured to a sheet of material prior to insertion into the container. The material may be cardboard. The upper corners of the fluid-tight bag may be secured to corners of the container after insertion into the container.
The lower flaps may be so arranged as to fold to form a completely covered lower end for the container. The upper end flaps may be of a length such that, when folded over to form a top to the container, they permit access to the fluid-tight bag. The upper end flaps are preferably folded over to form the upper end and secured in position prior to filling the fluid-tight bag. The upper end flaps may be secured in position with self-adhesive tape. There may be provided an abrasion-resistant liner between the support struts and the fluid-tight bag. The abrasion-resistant liner may be in the form of a tube having substantially the same external cross-section as the internal cross-section of the container.
The upper tension means may be joined together where they cross, there may be provided an aperture through the conjoined region of the upper tension means. In the alternative the upper tension means may be flexible and may be formed of a webbing.
The container preferably has a plan area substantially identical to that of a standard pallet. The fluid-tight bag may be formed of an unreinforced plastics material or alternatively may be formed from a fabric reinforced plastics material. The bag may be provided with an entry filler point and an exit emptying point. Preferably the emptying point is located at the bottom of the bag and the filler point is located at the top of the bag.
The present invention also provides a kit of parts for a container comprising the features set out above. The present invention also envisages the assembly of a kit of parts and the filling of the so-assembled container, including the steps of folding in the lower flaps to form the base of the container, locating the lower tension means in the base of the container, inserting the support struts into the container, positioning the support struts over the lower tension means and securing the support struts to the walls, locating the abrasion-resistant liner in the container, attaching the base of the fluid-tight bag to a sheet of material, inserting the sheet of material into the base of the container, securing the upper corners of the fluid-tight bag to the corners of the container, locating the upper tension means over the bag on the upper ends of the support struts, closing the upper end flaps to form the upper end of the container and subsequently filling the fluid-tight bag with a fluid.
The container may be positioned on a pallet prior to filling. A lid may be located on the container after filling. The lidded container may be strapped to the pallet.
BRIEF DESCRIPTION OF THE DRAWINGS
By way of example embodiments of the present invention will now be described with reference to the accompanying drawings, of which;
FIG. 1 is a perspective view of a container in accordance with the present invention;
FIG. 2 is a side part sectional view of the connection between a support member and a tension member;
FIG. 3 is a perspective view of alternative tension members; and
FIG. 4 is an elevational view of a toggle and reinforcing plate.
FIG. 5 is a perspective view of an alternative form of container;
FIG. 6 is a plan view of the tension means of FIG. 5;
FIG. 7 is an enlarged view of the connection between the post and the tension means of FIG. 6; and
FIG. 8 is a perspective schematic view of an alternative form of upper tension means.
FIG. 9 is an exploded view of a container in accordance with the present invention;
FIG. 10 is an enlarged view of a corner of a portion of the container of FIG. 8 illustrated in the circle; and
FIG. 11 is a perspective view of an alternative form of container construction.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 this shows a standard ISO pallet 1 on which is located a container indicated generally by 2. The container has four walls 3, 4, 5 and 6 which are formed from Triwall triple wall thickness corrugated cardboard. The top of each wall is formed into an integral flap such as 7, 8, 9 and 10 which can be folded over to form the top. It will be appreciated that the flaps need not extend completely over the top of the container. Similar flaps or extensions are formed on the bottom of each of the walls to be folded in to form the bottom of the container.
Located within the container are four wooden support struts or posts such as 11, 12, 13, and 14. Each of the posts is formed of wood and has a size approximately 5 cm×8 cm. The wooden posts extend for the entire height of the container and are located in place on the external walls of the container by means of turn buckles such as turn buckle or toggle 15. The toggle or turn buckle 15 is rotatably mounted on the post and can be pushed through an elongate slot 16 in the wall 3 and rotated to locate the toggle firmly in position and hence locate the upright post 11 firmly in position. For standard pallets of 1 m plan area it has been found preferable to use two toggles and further it has been found preferable to use a reinforcing plate 17 to spread the load of the lower toggle 18 over a greater area. The spreader or reinforcing plate 17 may be formed with integral corners such as 19 which dig into the corrugated cardboard to locate it firmly in position. If desired the spreader or reinforcing plate 17 may be provided with corrugations to increase its resistance to bending.
As can be clearly seen, in the upper regions of the container there is provided a pair of tension members 20 and 21. The tension members are in the form of steel straps which are located to interconnect opposing support struts 12 and 14 and 11 and 13 respectively. The tension members have integrally formed tabs such as 22 (FIG. 2) which frequently engage the support struts.
Located within the cardboard container is a fabric reinforced flexible bag illustrated dotted at 23. It has been found that with a standard 1.12 m 2 pallet a container having a volume of about 1 m 3 can be provided directly on the pallet without the need for any external reinforcing collar to be provided. This means that the full plan area of the pallet can be used and the container can have a maximum internal volume for the transport of fluids.
The pallets may be stacked one on top of the other and the support struts 11, 12, 13 and 14 provide strength to the container such that stacking can comfortably occur.
Referring to FIG. 3 this shows an alternative form of tension means in the form of a pair of metal straps 24, 25 which are formed with an enlarged central region 26. The enlarged central regions are spot welded together as at 27 and are provided with an aperture 28 through which the entry valve for the container 23 can be passed.
Referring to FIG. 4 this shows in more detail the toggle and reinforcing plate. The toggle 29 is inserted through an aperture 30 in the plate and wall and rotated to engage with the reinforcing plate 31 and hold the plate firmly against the wall of the container.
Referring to FIG. 5 this shows an alternative form of tension means in a container generally illustrated as 40. The container is supported on a standard ISO pallet 41 and is formed of a cubic fibreboard body 42 having extension flaps 43, 44, 45 and 46 forming the upper end of the container. The lower end has similar extension flaps not shown. As before there are four support posts 47 to 50 which in this embodiment are bolted to the walls of the container. Bolts such as 51 are used and the load imposed by the bolts is supported by spreader plates 52. As before two bolts and spreader plates per post are used as is clearly illustrated in the drawings. In the embodiment illustrated in FIG. 5 the loads imposed on the posts tending to spread them apart are restrained by a square tension member indicated generally as 53. The tension member is in the form of an open square or window frame having four legs 54, 55, 56 and 57. The member 53 is secured to each of the posts 47 to 50 as is illustrated in more detail in FIG. 7 and as will be explained below.
The loads imposed on the posts such as post 47 are generally in the direction of the arrow 58. The picture frame 53 restrains the outward movement of the posts 47 to 50 by each leg being in tension in a similar manner to the method illustrated in connection with the embodiment shown in FIG. 1. It can be seen by resolving the forces acting in the legs of the picture frame 54 to 57 that the forces 58 can be resolved into pure tensile components in the legs 54 to 57. As before a fluid-tight bag 59 is located inside the container to hold the liquid.
Referring to FIG. 6 there is shown in plan view the picture frame member 53 which is secured to each of the upright posts 47 to 50. The most convenient method of securing the picture frame to the posts is illustrated in FIG. 7. It can be seen that the corners of the picture frame are bent over as at 60 and slip over the back of the post such as post 50. If required the bent-over flaps could be nailed to the post 50.
In an alternative form of tension means illustrated in FIG. 8 the tension means comprises a wire loop 61 formed at each corner with a downwardly directed peg 62. The ends of the loop may be formed to go into a single peg as at 63. The wire loop is held in the posts by driving the pegs 62 into the posts in the manner of nails.
For ease of understanding there is illustrated in FIG. 9 an exploded perspective view of a container in accordance with the present invention. The container is located on a wooden pallet 70 of conventional design. Located immediately on top of the wooden pallet is a fibreboard box 71 which has lower end flaps folded over from each of the sides to form a lower end wall 72. The width of the flaps is a half of the width of the wall so that the end flaps meet to form a double layer base. Located within the container 71 is a lower cruciform 73 which engages the lower ends of four wooden posts 74. The wooden posts are each secured to their respective side faces by means of bolts 75 which are secured to the side walls with load spreading plates 76. The upper ends of each of the walls are provided with flaps 77 which are folded later during the construction and filling of the container.
A loose cardboard sheet liner 78 is then inserted into the container. The height of the sheet 78 is approximately the same as the height of the container 71. This protects the flexible bag from chafing against the post 74.
After the liner 78 has been inserted the flexible bag 79, which has been taped to a cardboard base 80, is located in the container. The cardboard base 80 serves to hold the bottom of the flexible bag 79 accurately in position within the container and eases filling of the container with liquid. When using very thin flexible bags it has been discovered that in the absence of locating the bottom of the bag accurately in the container 71 the bottom can become creased and the creases are held in position by the weight of liquid filling the bag. As is illustrated in detail in FIG. 10 it can be seen that the corners of the base 81 of the bag 80 are taped to the cardboard sheet 81 by means of conventional flexible transparent tape such as 82.
The upper corners of the bag 79 are each provided with extensions 83, 84. These extensions may be in the form of loops or simple strips. The extensions are laid out through the corners of the container in the space between the edges of the flaps 77. Thus the extension 84 would be taken through the gap 85 and held in position on the fibreboard container by means of a suitable adhesive tape.
The upper cruciform 86 would then be located over the flexible container and secured to the upper ends of the wooden posts 74. The filler aperture 87 is then located in the aperture 88 in the cruciform 86. The flaps 77 are then turned over on top of the container and taped in position. The container may then be filled with liquid and after filling the filler aperture 87 can be released from the cruciform 86 to reduce excess tension loads on the material of the bag 79. The cardboard cap 89 is then placed on top of the container and the entire filled container can then be banded to the pallet 70 by use of steel bands in the conventional manner.
It will be appreciated that although there is described above containers utilising only one vertical post per side, if the length of the container became greater than that for which one post was suitable two or more posts per side could be used. Such an arrangement is illustrated in FIG. 11 and it can be seen that the side wall 90 of the container is provided with a pair of posts 91, 92. The upper and lower cruciforms are each provided with a single spine 93 to interconnect end posts 94 and 95 with a pair of cross members 96, 97 to interconnect posts 91 and 98 and 92 and 99 respectively.
Clearly, each of the end walls could be provided with two posts and it may be desired to provide three or more posts on one or more sides.
It will be appreciated that lower tension means are provided at the lower end of each of the posts in the container. Clearly the lower tension means could be of the same type as the upper tension means or alternatively different types could be used at the top and bottom of the container.
|
A container for fluids intended for use on a standard pallet, the container being formed of an outer fibreboard skin with an inner fluid-tight flexible bag, a series of posts each located vertically in the middle of a face of the container between the fibreboard skin and the flexible bag with a series of tension struts interlocating the upper and lower ends of the posts to prevent the bag expanding the container. The container is suitable for handling liquids or dry powder type fluids and can accommodate weights of the order of one ton while being easily dismantleable for despatch or storage. The container can be stacked three or more high.
| 8
|
BACKGROUND OF THE INVENTION
[0001] This invention relates to means for enhancing road traffic safety by preventing accidents, delays and other complications frequently caused by curiosity and unwarranted activities on the part of travelers on a roadway passing the scene of a previous accident that is under clean-up and investigation by rescue and law enforcement personnel.
[0002] Under present-day traffic conditions on express roads and highways, particularly in inclement weather, it is a common occurrence that a more or less serious accident becomes the cause of traffic jams and/or additional accidents due to the fact that other travelers slow down or even stop in the vicinity of the original accident scene in order to view the scene or, perhaps, in some cases to bring assistance to victims. This is the case both on the side of the road where the accident occurred and on the side of the road opposite to where the accident occurred. Such behavior frequently continues even after the arrival of emergency vehicles, such as police or patrol cars, towing cars, fire trucks, ambulances or the like, in spite of the fact that the rescue work would be greatly facilitated if the road traffic proceeded as unhampered as possible.
[0003] Several devices have tried to provide solutions to this problem, each with limited success. For example, U.S. Pat. No. 193,573 to Tripp disclosed an improvement in movable partitions or screens consisting of a flexible screen that when not in use is up on a spring-loaded portable cylindrical roll. When in use, the screen may be unwound, extended and mounted to walls or to heavy-based, movable posts.
[0004] U.S. Pat. No. 4,124,196 to Hipskind disclosed a portable screening device having a non-transparent elongate sheet that is perforated to relieve wind pressure and is secured at one end to a spring-activated rod on which the sheet is windable, the rod being mounted within a portable cylindrical container having a longitudinal slot through which the sheet is movable for winding/unwinding while being prevented from passing entirely into said container through said slot. The container is intended to be mounted in an upright position to a bracket that is clamped to a stationary object, such as a car bumper, and the free end of the sheet can be extended and secured to a stationary object using ropes or a supporting post.
[0005] U.S. Pat. No. 6,733,204 to Paniccia disclosed a view shield device having a flexible screen that is spring wound within a cylindrical housing and exits therefrom via an elongated slot when pulled by a handle at the free end of the screen. Each shield can be removably mounted into one of a plurality of wells in a mounting block such that the shields extend upward, and one screen may be attached to another via hooks at the free end of the screen that attach to another housing, such that the screen of a first shield may be extended between and attached to a second shield so that a passing motorist may not see between the first and second shield housings.
[0006] Unfortunately, none of these devices is truly portable because they require the use of heavy bases or mounting blocks to secure the screen housings. In addition, these devices require specialized equipment or installation, such as special brackets or mounting posts, and they cannot be used effectively if these items are not present. Furthermore, these shield devices allow a viewer to see between the screens of adjacent devices and do not completely block viewers from seeing what is intended to be shielded from view. Moreover, none of these devices allows the user to increase the view shield area vertically to provide enhanced screening above the level of the adjacent screens, for example where the area to be screened is lower than the view area or can be viewed by motorists with a higher vantage point.
OBJECTS OF THE INVENTION
[0007] One object of the present invention is to provide means whereby a roadside accident scene may be rapidly and effectively shielded from the view of passing motorists.
[0008] Another object of the invention is to provide a screen and supporting equipment that can be conveniently carried by an emergency vehicle and readily erected in position to prevent travelers from viewing the accident scene and any associated rescue and clean-up activities.
[0009] A further object of the invention is to provide a screen for the purpose indicated, which is preferably made of a thin, light-weight material and is adapted to be carried by emergency vehicles in a compact condition.
[0010] Yet another object of the invention is to provide a portable screen that is subject to reduced wind pressure on the screen in its erected condition.
[0011] A still further object of the invention is to provide lightweight, yet sturdy, means for supporting the screen in proper position at the accident scene.
[0012] Another object of the invention is to provide a screening arrangement in which two or more screens of the type indicated above may be mounted one on top of another to thereby increase the total height of the screening device.
[0013] A further object of the invention is to provide a screening arrangement in which two or more screens can be attached one alongside another to thereby increase the total length of the screening device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Additional objects and features of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, in which
[0015] FIG. 1 is an overhead view of an accident site at the edge of a three-lane expressway,
[0016] FIG. 2 is a side view of the screening device according to the invention,
[0017] FIG. 3 is a perspective view of attaching means affixed to the outside of the cylindrical container for attaching the cylindrical container to an adjacent screen, and
[0018] FIG. 4 is a perspective view of attaching means affixed to the free end of the screen for attaching the screen to an adjacent cylindrical container,
[0019] FIG. 5 shows, in side elevation, an erected screening device with a second and a third similar screen mounted on top thereof, and
[0020] FIG. 6 is a perspective view of the base for supporting the screening device.
DETAILED DESCRIPTION OF THE INVENTION
[0021] FIG. 1 shows a section of an expressway with three traffic lanes 10 , 11 , 12 in one direction and three traffic lanes 13 , 14 , 15 in the opposite direction, as indicated by arrows 16 and 17 , respectively. Outside of lane 10 there is one shoulder 18 and outside of lane 15 is another shoulder 19 , while the space between lanes 12 and 13 is occupied by dividing region 20 , such as a double shoulder that could also be divided longitudinally by a barrier 21 .
[0022] FIG. 1 depicts the scene of an accident wherein an automobile 22 traveling in lane 12 was hit from behind by another automobile 23 , causing both vehicles to be partially thrown out of lane 12 onto the shoulder 20 , both vehicles in this example shown remaining in upright position. One or more occupants of the vehicles may have sustained injuries and, perhaps, have been thrown to the ground. Even if the two vehicles 22 , 23 directly involved in the accident have come to a halt entirely on the shoulder 20 , the drivers of vehicles following the second automobile in lanes 12 , 11 and 10 will in most cases stop or at least slow down in order to bring help or just plainly to “gawk” at the scene, and in the present case the vehicles in lane 12 will eventually attempt to move to lane 11 . In any case, a serious traffic jam will typically occur, usually with vehicles accumulating in long lines behind the accident site. Similar traffic congestion usually occurs also in one or more of lanes 13 , 14 , 15 for assistance and/or curiosity (“rubber-necking”) reasons.
[0023] The first emergency vehicle 24 to arrive at the scene will generally park behind the second automobile 23 with its warning lights flashing. In accordance with the present invention, the occupants of emergency vehicle 24 —policemen, firemen, or state troopers, etc.—will proceed to erect a screening device as described herein, which is preferably routinely carried in the emergency vehicle. As more such vehicles arrive, an embodiment of the continuous screen 25 is rapidly erected and expanded in lane 12 and subsequently on the opposite side of the accident site on the shoulder 20 , as at 26 , to effectively screen off the accident site from view in all directions and thus prevent traffic jams caused by curious “gawkers”.
[0024] The design and construction of the inventive screen will now be described in detail with reference to the drawings. As shown in FIG. 2 , the screening equipment carried in the emergency vehicle includes a housing or container 30 , which is preferably cylindrical and provided with closure plates 31 , 32 at both ends. Extending centrally through said container 30 is a tube 33 which is rotatably connected with the closure plates 31 , 32 in the same manner as an ordinary curtain rod of the kind containing a coil spring 34 . One end of the spring 34 is secured to a member 35 which is rotatably connected with the tube 33 and non-rotatably mounted in the plate 31 , while the other end of the spring 34 is secured to the tube 33 at the opposite end thereof.
[0025] The container 30 is provided with a longitudinal slot 36 that extends preferably from one end of container 30 to the other end of container 30 . A sheet 37 of a flexible material to be described below retractably extends through slot 36 . One end of said sheet 37 is secured to the spring-loaded tube 33 in the manner of a shade or curtain to a curtain rod. The opposite end of the sheet 37 is provided with attaching means 40 , as described below, that prevents passage of sheet 37 through the slot 36 into the container 30 .
[0026] A rod 38 may be secured to container 30 alongside the slot 36 to prevent frictional damage to the sheet by the edges of the slot 36 , as it is moved therethrough. Rod 38 may have a round or any other cross-sectional shape, provided that it has a smooth surface in order to minimize friction on sheet 37 as it is unrolled from and rolled into the container 30 through the slot 36 . Rod 38 is preferably affixed at its ends to the plates 31 , 32 and is preferably set in a position relative to slot 36 such that it minimizes the contact between sheet 37 and the edges of slot 36 .
[0027] The sheet 37 is preferably a thin, lightweight material that is strong, durable and preferably weather-resistant, such as a cloth-backed vinyl or similar material. The sheet 37 is preferably provided with apertures or perforations 39 of a size and spacing to relieve wind pressure on the sheet, when in extended position of use, as described below. In a preferred embodiment, the apertures 39 are not completely cut through but rather remain partially attached to the sheet 37 on one side of the perforation. For example, one embodiment, the apertures 39 have a triangular shape, as shown in FIG. 2 , with the material of each triangular perforation being attached to sheet 37 at one base side thereof rather than being completely cut-out. Apertures 39 should be sufficiently small to prevent easy viewing therethrough, particularly from a moving vehicle, but to allow passage of wind therethrough.
[0028] The sheet 37 may be made any thickness, height and length as desired. A preferred thickness of the sheet, or screen, 37 is approximately 0.5 cm or less, and a preferred height is approximately 4-5 feet. The length of sheet 37 may vary considerably as, for example, from about 10 to about 50 feet.
[0029] At the free end of the sheet 37 is an attaching means 40 , as described below, for selectively attaching a first sheet 37 to another container 30 , as described below. When arranged for storage or to be carried by an emergency vehicle, the screen 37 is preferably retracted, in the manner of a rolled-up window shade, so that it is tightly wound around the tube 33 in the container 30 with the spring 34 under minimal tension. However, because the width of attaching means 40 is larger than the width of the opening of slot 36 , the attaching means 40 is situated immediately outside the slot 36 when sheet 37 is arranged for storage and provides a handle for pulling sheet 37 out of the container 30 . The arrangement of the spring 34 is such as to place the screen 37 under ever increasing tension as the screen 37 is being pulled out of the container 30 .
[0030] Each emergency vehicle (police or patrol car 24 , etc.) carrying one or more container 30 with the screen 37 in rolled-up condition therewithin is preferably provided with means for easy and speedy mounting and retaining of the container 30 thereon in an upright position. In a preferred embodiment, in order to enable the screen to remain upright on the road surface on which it is placed, a base 60 is secured to the bottom of container 30 . The base 60 preferably should be composed of a strong and durable material and should be of a sufficient circumference, thickness and weight to provide support for the screening device under adverse weather conditions. The base 60 should also be of dimensions that allow for easy transportation, such as in the trunk of emergency vehicle 24 .
[0031] As shown in FIG. 6 , the base 60 should preferably contain a protrusion 61 with external screw threads about its vertical circumference to allow attachment to the container 30 . In order to accommodate the protrusion 61 of the base 60 below it, the bottom closure plate 31 of container 30 has a hole 52 with corresponding internal screw threads around its interior circumference to allow protrusion 61 to be mated therewith for secure attachment. Each protrusion 61 can be attached to a bottom closure plate 31 of container 30 in the same manner as a screw is fastened into a bolt. Alternatively, the bottom closure plate 31 of container 30 may contain the threaded protrusion that is to be mated with a hole formed within base 60 having corresponding internal screw threads. Of course, container 30 and base 60 may have any other suitable mounting connection that allows quick mounting of container 30 onto base 60 and de-mounting therefrom and provides a secure and stable connection while container 30 is mounted on base 60 .
[0032] As shown in FIG. 1 , two or more screens 37 may be attached one to another to provide lengths of view shielding that are greater than one screening device alone will physically allow. The attaching means can be any device that detachably attaches one screen 37 to the container 30 of an adjacent screen, such as hooks, clips, bolts, tabs, detents, interlocking or mating parts, etc. The attaching means should preferably have no external parts that could be misplaced and thereby prevent attachment of one screen to another and should preferably be of a lightweight material, such as a type of metal or hard plastic, that is strong and durable to enable the screen 37 to remain securely attached to the other container 30 .
[0033] The attaching means can also be a mating structure. For example, as shown in FIGS. 3 and 4 , screens 37 are attached via attaching means, generally indicated at 40 and 41 . At the free end of the screen 55 is fastened a first mating attaching means 40 which is preferably of a length and thickness to enable the screen 37 to remain securely attached to the corresponding attaching means 41 affixed to another container 30 . A second mating attaching means 41 , which should also be of a length and thickness to enable the container 30 to remain securely attached to the screen 37 , should be fastened to the vertical side portion of each container 30 , for example by screws 42 or some similar affixing means, in an upright position.
[0034] The screen 37 is pulled out of its container 30 to the desired length. The screen 37 is then lined up with another container 30 such that the emergency personnel is able to slide the attaching means 40 into the corresponding attaching means 41 to mate therewith. In the embodiment shown in FIGS. 3 and 4 , wherein attaching means 40 is inserted downward into attaching means 41 to mate therewith, the bottom portion of each attaching means 41 should be closed in order to prevent any detachment. In a preferred embodiment, as in FIGS. 3 and 4 , the free end of a first screen 37 is attached flush against the adjacent container 30 to provide no space or a minimum space between them so as to prevent viewers from looking between the screens of adjacent devices and being able to see what is intended to be shielded from view.
[0035] As shown in FIG. 5 , two or more screens 37 may be mounted one above another in order to provide greater view shielding in the vertical direction. In order to allow one screen to be mounted above another, each container 30 has a rod, flange or other protrusion 50 , secured to and extending upwards from the top side of the upper closure plate 32 of the container 30 that is shaped, as protrusion 61 of base 60 , to mate with hole 52 located in the bottom closure plate 31 in order to accommodate the protrusion 50 of a container 30 below it. Alternatively, the bottom closure plate 31 of container 30 may contain the threaded protrusion 50 that is to be mated with a hole 52 that is formed within the upper closure plate 32 of the container 30 below it. The protrusion 50 should have external screw threads 51 around its vertical circumference and the corresponding hole 52 should preferably have corresponding internal screw threads around its interior circumference, as discussed above. Each protrusion 50 of a first container 30 can be secured with hole 52 of another container 30 in the same manner as a bolt is fastened to a screw. Of course, container 30 may have any other suitable mounting connection that allows quick mounting of another container 30 thereon and de-mounting therefrom and provides a secure and stable connection while one container 30 is mounted onto another.
[0036] In this manner, protrusion 51 extends above the upper edge of the screen a sufficient distance for connection with a screen container 30 belonging to a second screen above it, to form an extension upwardly of the screen 37 , when required. Alternatively, protrusion 51 may extend below the lower edge of the screen a sufficient distance for connection with a screen container 30 belonging to a second screen below it. A third screen may be similarly mounted above said second screen. In most cases one (or two) screen has been found sufficient, since the activities on or close to the ground behind the screen usually are what most interest the “gawkers”. In order to enable the stacked screens to remain upright on the road surface on which it is placed, a base 60 , as described above, is secured to the container 30 of the bottom-most screen 37 .
[0037] Thus, a portable screening device has been provided. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not limitation, that the invention is not restricted in any respect by the specific details described and shown, and that numerous modifications and mechanical equivalents are also feasible within the scope of the foregoing descriptions.
|
A screening device has elongate sheet of a thin non-transparent material windably mounted at one end to a spring-activated rotatable rod within a portable housing having a longitudinal slot through which the sheet is movable for winding and unwinding purposes while being prevented from passing entirely into said container through said slot. The container is provided at one end thereof with means for readily and releasably connecting the same in an upright position with a stationary object, while a supporting post is connectible to said sheet at the free end thereof and adapted to be secured to a stationary object at a distance from said first mentioned stationary object to thus support the unwound sheet in a substantially vertical position.
| 4
|
TECHNICAL FIELD
[0001] The present invention relates to an advanced capillary fill design, and more particularly to a pre-defined and guided capillary fill design for a medical device such as a biosensor, or for any other advanced devices using capillary mechanism to fill a small chamber for quantitative and qualitative analysis.
BACKGROUND
[0002] In recent years, biosensors have been rapidly developed to detect all kinds of diseases. A conventional biosensor is provided with a rectangular substrate with two adjacent graphite electrodes, which are substantially parallel with each other, attached thereon. A reference electrode and a functional electrode are correspondingly attached to these two graphite electrodes, with a protective plastic film, such as a PET film, arranged thereon. The working electrode may perform an enzyme catalytic reaction, and electrons so produced are transferred to electrodes via an electron carrier. Since the intensity of this electric current is relevant to the activity of the enzyme and the concentration of a particular ingredient (such as glucose) in the test sample, this particular ingredient (such as concentration of the glucose) may be readily detected by said biosensor. During operation, testing solution is sucked into a reaction chamber, in which the enzyme electrode is disposed, through capillary action. Accordingly, hydrophilic films have to be provided in the reaction chamber so that a testing solution may reach into the chamber. However, plastic as PET is usually hydrophobic, so that it has to be surface treated to form a hydrophilic coating. This hydrophilic coating will gradually lose its hydrophilic function as time goes on, especially in severe environment. Meanwhile, this hydrophilic coating may not work in aggressive environment, such as under high humidity, and may get damaged easily.
[0003] Another problem for a conventional biosensor is that manufacturing thereof is relatively complex. For a conventional biosensor, it is necessary to provide a breath space or a hole at the end of the reaction chamber. Otherwise, pressure will be built up within the chamber immediately after testing solution is applied, therefore creating a resistance to stop the testing solution from further entering into the reaction chamber. Furthermore, these breath spaces or holes may easily get blocked, therefore deteriorating the functionality of the biosensor and increasing the analytical error.
[0004] Surface treatment, as well formation of breath spaces or holes in a biosensor complicates the manufacturing process of the biosensor, increases the cost thereof, and makes it damageable.
SUMMARY OF THE INVENTION
[0005] Therefore, an object of the present invention is to provide a novel pre-defined and guided capillary fill design for a medical device or any other advanced devices using capillary mechanism to fill a small chamber for quantitative and qualitative analysis, which may be easily manufactured and operated with a high accuracy, without the need for a delicate hydrophilic coating on hydrophobic plastic film.
[0006] According to one aspect of the present invention, a device with a predefined capillary fill design comprises a substrate, a working electrode, a reference electrode, a functional electrode, a reaction chamber and a plastic covering film, wherein the reaction chamber is provided with one or more hydrophilic guiding channels extending from the entrance of the reaction chamber.
[0007] Preferably, the hydrophilic guiding channel is formed by depositing any hydrophilic ingredient on the substrate, such as by thick film printing, injection printing, spraying, or other coating methods.
[0008] Preferably, the hydrophilic ingredient is an enzyme catalytic reaction reagent. Optionally, the hydrophilic ingredient is a mixture of surfactant and enzyme catalytic reaction reagent.
[0009] Preferably, the height of the reaction chamber is within the range of 0.001 mm to 1 mm and the length of the hydrophilic guiding channel is no less than 0.5 mm.
[0010] Preferably, the entrance of the reaction chamber may be configured to be circular, semi-circular, elliptical, semi-elliptical, rectangular, square, triangular, trapezoidal or any other suitable shapes or a combination thereof within the region of reaction chamber.
[0011] Preferably, the electrodes in the present invention such as the reference electrode and the functional electrode are made by dispersing powder materials from micrometer scale down to nanometer range in macromolecular solutions whereby developing congeries and cavities within nanometer range therein.
[0012] Preferably, the plastic covering film is a normal hydrophobic plastic film such as a PET film with a thickness of in the range of 0.05 mm to 1 mm. And optionally, the plastic covering film is transparent, semi-transparent or opaque with or without color.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Hereinafter, the present invention will be further described in detail with reference to the accompanying drawings.
[0014] FIG. 1 illustrates a front view of a capillary fill device according to an embodiment of the present invention, with the top plastic film removed from the device.
[0015] FIG. 2 illustrates a front view of the capillary fill device according to the embodiment of the present invention, with the top plastic film applied on the device.
[0016] FIG. 3 illustrates a side view of the capillary fill device according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0017] A capillary fill biosensor, which is an example of the capillary fill device according to one embodiment of the present invention, is employed to measure the concentration of glucose within blood. As shown in Figures, the capillary fill biosensor according to the present invention comprises: a substrate 1 ; a working electrode 2 ; a reference electrode 3 ; a functional electrode 4 ; a reaction chamber 5 ; and a plastic covering film 6 . The reaction chamber 5 is provided with one or more (only one is shown in the figures) hydrophilic guiding channels extending from the entrance of the reaction chamber. The testing solution such as blood sample to be tested flows to the reaction chamber 5 through the one or more channels via capillary mechanism.
[0018] The substrate 1 may be made up of a sheet of plastic, such as PET, with a thickness in a range of 0.1 micrometer up to a few millimeters. Electrode 2 is printed with conducting graphite paste by thick film printing technology. Afterwards, mixture of silver and silver chloride is printed on the substrate 1 to form electrode 3 . The printing thickness is in the range of 5 micrometers to 20 micrometers. The functional electrode 4 is similarly formed by printing a paste, which is achieved by mixing with conducting materials such as Au, Pt or Pd, onto substrate 1 . Active ingredient, i.e. enzyme catalytic reaction reagent, is deposited in reaction chamber 5 by thick film printing technology to form a guiding channel. It should be understood that other coating methods may be employed, such as injection printing, spraying, and the like. The deposited ingredient is bydrophilic in nature. Otherwise, surfactant may be added into the active ingredient to make it hydrophilic. Thus, a predefined and guided capillary flow channel is appropriately formed. The length of this guiding channel is around 1.5 mm, which may vary from 0.5 mm to a few millimeters or longer depending on applications. Afterwards, a conventional hydrophobic plastic film 6 of transparent, semi-transparent or opaque with or without color, with a thickness in a range of 0.05 mm to 1 mm, preferably about 0.125 mm, is glued onto the top of the substrate 1 and all electrodes. However, above the reaction chamber 5 , no glue or adhesives are provided (see FIGS. 2 and 3 ). That is to say, in the region where the active hydrophilic ingredient is deposited, a gap free of glues or adhesives is formed between the active ingredient layer and the plastic film. The height of the reaction chamber 5 is designed to be from 0.001 mm to 1 mm. A design in which a hydrophilic surface of the active ingredient is faced with a hydrophobic surface of the plastic film 6 further promotes a capillary action. When a testing solution such as a blood sample is applied to the entrance end of the reaction chamber 5 , the blood will be quickly sucked into the reaction chamber 5 via capillary mechanism. It usually takes less than 1 second, more preferably less than 0.5 second, for blood to complete the capillary action.
[0019] The biosensor shown in FIG. 1 can still perform an accurate analysis even though the sample volume goes down to a very low value, such as within a range of 0.12 μl to 0.24 μl, which is the smallest test volume for a glucose biosensor available today. By further decreasing dimensions of electrodes and reaction chambers, less testing solution is required in an analytic process. For example, in a smaller biosensor, a blood sample with a volume less than 0.1 μl may be sufficient, while the accuracy of the testing result will remain substantially the same. Therefore, by the novel design of the present invention, a sample may be analyzed easily and accurately, even though the volume of the sample is really small.
[0020] The entrance of the reaction chamber 5 may be configured to be circular, semi-circular, elliptical, semi-elliptical, rectangular, square, triangular, trapezoidal or any other suitable shapes within the region of the reaction chamber. A combination of these configurations is also possible, depending on the application of the biosensor.
[0021] Particularly, electrodes in the present invention are made up of nano materials. Graphite, silver and silver chloride materials are all powders within nanometer range. These tiny powders are dispersed in macromolecular solutions. Therefore, congeries and cavities within nanometer range are developed in electrodes. Thus, reaction area is greatly increased and the accuracy of the analytic tests is greatly improved.
[0022] It has been proved that with a biosensor with a pre-defined and guided capillary fill design according to the present invention, a test solution such as blood may be sucked into reaction chamber in a short time less than 1 second, most often in 0.2 second, through capillary mechanism. The analytic volume of the sample may be effectively controlled by changing the length of the guided channel and the height of the reaction chamber. Therefore, a biosensor with present design may operate with a high accuracy and free of blockage.
[0023] It should be noted that the embodiment of the present invention shown in the drawings has only one hydrophilic guiding channel within the region of the reaction chamber, however, the device with a predefined capillary fill design according to the present invention can have multiple channels for the same or completely different assays for biological diagnostic or other applications. In this case, it can also deposit different assay reagents to form different artworks together, or separately or combined the two to form multiple assays, for example, several parameters of blood tested in one go.
[0024] Although the invention is described in detailed with a medical device such as a biosensor, it is also applicable to any other advanced devices using capillary mechanism to fill a small chamber for quantitative and qualitative analysis. The fields to which the present invention is applicable include but are not limited to biological, chemical, environmental and food science, and the like.
[0025] Furthermore, while an embodiment of the present invention has been described with reference to accompany drawings, it is to be understood that the invention is not limited to details of the illustrated embodiments. A person skilled in the art may understand that amendments and modifications can be made without departing from the scope of the present invention as disclosed in the claims. All these amendments and modifications shall fall within the scope of the present invention.
|
The present invention discloses a device with a predefined capillary fill design comprising a substrate ( 1 ), a working electrode ( 2 ), a reference electrode ( 3 ), a functional electrode ( 4 ), a reaction chamber ( 5 ) and a plastic covering film ( 6 ), wherein the reaction chamber ( 5 ) is provided with one or more hydrophilic guiding channels extending from the entrance of the reaction chamber ( 5 ). Therefore, the device according to the invention may be easily manufactured and operated with a high accuracy, without the need to provide a delicate hydrophilic film with special coating.
| 6
|
TECHNICAL FIELD
[0001] This invention relates in the majority to snow shovels or similar burden carrying devices having an auxiliary handle tethered in such a way as to be retractable to a conveniently stored disposition.
BACKGROUND OF INVENTION
[0002] It is well known to those skilled in the art that ergonomic handle principles attempt to reduce bending of the lower back thereby reducing spinal injury. In the 1907 U.S. Pat. No. 845,592 to Stewart, we are taught that an upward bend in the handle located proximal to the shovel scoop will elevate the forward grip position reducing the curvature of the operators spine. We are also taught in the 1903 U.S. Pat. No. 725,905 to Williams, that lifting and carrying of a load is made easier if the forward grip position is moved directly above the load as described mathematically in mechanical moments of the laws of levers.
[0003] In the 1909 U.S. Pat. 911,291 to Byor, we are shown that the forward grip position can be elevated to any height using an auxiliary grip with an adjustable resilient shank member with means for securing the same to the primary handle shaft. In the 1950 U.S. Pat. 2,521,441 to Bickley, we are taught that a flexible cord with terminating hand piece also elevates the forward hand grip point while improving the free universal action to throw material sideways and the mechanical efficiency of having the load placed directly under the hand grip point for lifting.
[0004] The U.S. Pat. No. 4,200,324 to Helton, describes disposition methods of storage for grips tethered by means of flexible material using retaining holes or clips located on the primary handle.
[0005] In U.S. Pat. No. 5,704,672 to Sims, the flexible cord is described as a resilient bungee cord which lengthens and shortens a portion of it's length to facilitate a smooth shoveling action but does not attempt to solve the problem of disposition. Like wise in U.S. Pat. No. 4,531,713 to Balboni, an elastic line lengthens and shortens to form a retrieval. Although prior art describes flexible means acting as ergonomic handles, the storage and disposition of said means of auxiliary handle is inconvenient and in the majority, prior art grips with flexible cord means are allowed to drag, impact, sag or traverse universally during the stroke of the tool. For a stand up shovel to be commercially accepted the auxiliary grip must be suitably arranged for convenience and the necessary elements defined so that the handle is advantageous and not obstructively placed to the traditional use of the shovel and as such, prior art has been unable to compose the necessary elements. Further, in a shovels introduction to the burden for loading and unloading, the flexible cord means should not cause the scoop to hover or bounce but should have a fixed length for elevating the load upwards on to a pile without having heavier loads cause the scoop to fall farther away towards the ground and the auxiliary grip should be completely and easily retracted safely out of the way when not in use.
[0006] In addition to the advantages of reduced spinal curvature produced by a stand up shovel, a hand grip located for maximum mechanical efficiency and extensible through a low force biasing means from a comprehensible storage disposition has not been taught in prior art.
[0007] Further, to facilitate a wide variety of dispensing locations for an extensible tethered grip, a pulley or sheave means described as a fixed curvature in Canadian Patent 2,188,956 to Stuart, teaches how non-rotating sheaves described as, curved surfaces or irregular contours, may act as guides to effect change in direction for dispensation of flexible string means such as polymer cordage or wire ropes.
DISCLOSURE OF INVENTION
[0008] It is the primary purpose of the present invention to provide an ergonomic shovel handle in accordance with prior art for stand-up shovels which will include a readily accessible auxiliary hand grip easily withdrawn from a pocket located on the shovel.
[0009] It is also a purpose of this invention to provide an opening substantially within the scoop area for the egress of a tether attached to said hand grip or in another form of this invention to provide an anchor point within the area of the scoop as a means of tethering an auxiliary grip.
[0010] It is also a purpose of this invention to provide a curved surface and guiding means in preference of a freely rotating sheave within the primary handle to facilitate redirecting the tether towards the hand grip and from the anchor point. Said guiding means may be constructed to act as a blocking means to limit the extension length of the tether.
[0011] It is a purpose of this invention to provide an anchor point, for a tension spring or longitudinally elastic element, substantially within the primary handle at a point distal from said egress and blocking means and substantially interposed of a “D” shaped grip located on the primary handle.
[0012] In it's simplest form, according to the preferred elements of the present invention, said hand grip may be formed of a hollow cylinder interposed by a flexible string means looped to form an “A” shape as part of a tethering means of a return line which includes a biasing means at the opposite end At a point along the tethering means length is located a blocking means for the purpose of limiting the extension of the hand grip and indirectly lifting the scoop from a point behind the guiding means.
[0013] It is also the purpose of the present invention to provide a holder or pocket for storage of the retracted hand grip within the embodiment of the shovel and in some cases strengthen the said pocket to act as a load bearing point for lifting using said tethering means.
[0014] It is also an objective of this invention to provide an alternative biasing means and tether means for the auxiliary grip in the form of a reel mechanism to wind up or be pulled out. The said reel mechanism may be formed as part of the shovel scoop, as part of the grip or as part of a unitary shovel embodiment.
[0015] It is also a purpose of this invention to provide the best shoveling action so that the scoop rests upon the ground with the hand grip conveniently grasped by the user standing erect. The opposition of return line retraction force to the force of gravity holding the unburdened weight of the scoop upon the ground must be matched so that the scoop will be held in it's distal position by gravity upon the blocking means and not hover or bounce elastically from the tension of the biasing means.
BRIEF DESCRIPTION OF DRAWINGS
[0016] The preceding and other objectives of this invention will be more readily apparent from the following description read in conjunction with the accompanying drawings, in which:
[0017] [0017]FIG. 1 is a perspective view of the invention with grip extended;
[0018] [0018]FIG. 2 is a perspective view of the invention with grip retracted;
[0019] [0019]FIG. 3 is a broken out section side view of the primary handle;
[0020] [0020]FIG. 4 is a perspective view of an anchor;
[0021] [0021]FIG. 5 is a perspective view of tether guide;
[0022] [0022]FIG. 6 is a partial side view section drawing of pocket storing grip;
[0023] [0023]FIG. 7 is a partial top view of a grip and pocket;
[0024] [0024]FIG. 8 is a perspective view of a grip with reel mechanism;
[0025] [0025]FIG. 9 is a partial view of a deposition framework for storing retracted hand grip, and
[0026] [0026]FIG. 10 is a partial section side view taken along line A-A of the framework of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring in detail to the drawings, in FIG. 1 the shovel of the present invention includes an elongated primary handle 1 , with one end attached to a shovel scoop 2 , showing the extensible auxiliary grip 3 , extended from its holder. The primary handle 1 , may be formed as a hollow tube or with linear slots or similar means of cavity which will allow free unrestricted motion of the means of return line 40 , towards the anchor point 15 .
[0028] The extensible auxiliary hand grip may be formed as a hollow tube 3 , with the means of tether 4 , entering said hollow tube and looping in a typical “A” shape forming an accessible hand opening and hand hold 5 . The tethering means may be clamped, spliced or connected 6 , in a general “A” shape using any method commonly known to those experienced in the art for fixedly attaching the means of tether. In another form, the connection means 6 , may allow the length of the tethering means to be adjusted by the user as is generally know to those experienced in the art.
[0029] Also in FIG. 1, an egress opening 7 , for said tethering means 4 , may in its simplest form be a circular opening located on the primary handle socket 8 .
[0030] A “D” shaped grip 9 , is located at one end of the elongated primary handle of suitable size to facilitate stability during loading and unloading of the scoop to the side and to act as a fulcrum point when lifting a load using the auxiliary hand grip 3 . Said “D” shaped handle may be formed with a means of anchor 15 as part of the embodiment.
[0031] In FIG. 1 and FIG. 2, a left framing member 10 , and right framing member 11 , may be formed as part of the shovel scoop embodiment 2 , to form a slight cavity which will hold the extensible grip 3 , under the force of the return line as shown in FIG. 2. In the simplest form, said framing members use the retraction force of the biasing means 14 , of FIG. 3, to prevent inertial motion by placing the grip 3 , in mild compression against said framing members which form a notch or friction like keeper. Said framing members may be of increased complexity, shape and configuration as desired.
[0032] In FIG. 9, another form of opposed framing members 10 , and 11 , formed as part of the shovel embodiment or affixed, are shown having an opening on either side 32 , and 33 , where means of tether 4 , extends towards the said egress area 7 , of FIG. 1. The extension of tether 4 , through said openings 32 , and 33 , acts to reduce transverse motion of the hand grip 3 , caused by the inertia in the act of shoveling. In FIG. 10, as viewed through section line A-A of FIG. 9, the general curvature, groove, notch, or slot of said framing member 11 , is shown with an upper elevation or extension 34 , and a lower extension of the framing members 35 . These said extensions may be formed in any way which will generally capture the grip 3 , using the force of said biasing means of the return line for mounting said grip or to almost completely enclosed an auxiliary hand grip 26 , for stowage as in a pocket 25 , of FIG. 7.
[0033] In FIG. 9, a central opening 34 , located between said framing members is for hand access to the grip 3 , outlined with a dashed line.
[0034] [0034]FIG. 3, is another view of primary handle 1 , having a passage 13 , containing a biasing means, such as a helical extension spring 14 , anchored at one end of the handle 15 , and distally attached to the tethering means 4 , as a means of return line using an intermediary connection 16 , of greater dimension than aperture 17 , of means of sheave 18 , as a means of blocking to limit extension of the return line and guiding the said tethering means to an egress 7 , in FIG. 1. Said intermediary connection 16 , may in ifs simplest form be a suitable knot tied in said tether means. Said biasing means 14 , may also be a resilient elastic for warmer climates or of a material with elastic properties not effected by deeper cold
[0035] [0035]FIG. 4, one form of anchor 15 , of FIG. 1, is illustrated as a circular disc 19 , with an arm 20 , as a means of insertion into the terminating helical coil or intermediary connector of said biasing means. Slots 21 , on both sides of arm 20 , may extend past the centre of the disc 19 , to centrally locate a biasing means. The diameter of disc 19 , is greater than that of the primary handle passage 13 , of FIG. 3, but less than the inside diameter of “D” handle socket 36 , of FIG. 2. Said anchor may be any means commonly known to those experienced in the art including a hole in any part of the shovel embodiment distal from said egress.
[0036] Said means of sheave 18 , of FIG. 5, may be formed in any shape 22 , for insertion into said primary handle 1 , of FIG. 3. A step of larger dimension 23 , is required for controlling the depth of insertion into the said primary handle. Said means of sheave 18 , may be constructed to be located in any part of the shovel with steps and cut out sections or as part of the primary handle embodiment in any way commonly known to those experienced in the art for redirecting a tether at diverging angles from an anchor point with minimum friction An arc or curvature 24 , also shown in FIG. 6, is provided for dispensing the tethering means 4 , towards the grip 26 , for extraction and retraction of the extensible hand grip 26 , of FIG. 6, in a way suitable to act as a low friction pulley or sheave in guiding the tether from the primary handle 1 , to the egress 7 , on the shovel scoop 2 , of FIG. 1.
[0037] Means of sheave 18 , may be shaped to fit proximal to any elements of the embodiment of said primary handle 1 , or socket 8 , of FIG. 1. Said means of sheave my contain rotatable axles or other elements as required to guide the string means 4 , as commonly known by those experienced in the art
[0038] [0038]FIG. 6, shows another form of the present invention having a partly enclosed pocket 25 , formed as part of the shovel scoop embodiment for deposition or stowing another form of hand grip 26 , shown in FIG. 7. The extensible tether 4 , when extended, may in certain orientations, contact the inside pocket surface on the curvature 27 , which is formed and reinforced to act as a sheave or guide but mostly as a load bearing support for the force of the means of tether 4 , to act in opposition to the force of the load of burden held in the shovel scoop 2 . The egress point 7 , of FIG. 6, may also be enlarged to act as a fluid or debris drain into the handle socket 8 , cavity where it may be further drained using a second opening 29 .
[0039] Hand grip 26 , embodiment material may be elastomeric or rigid of any thickness or form having a channel 35 , of FIG. 6, where tethering means 4 , may enclose in an “A” shape and provide strength to the auxiliary hand grip 26 . Said pocket may be formed in any way as to mimic the form of said hand grip for the best combination of properties for storage and ease of access.
[0040] In another form of the present invention shown in FIG. 8, the said tethering means and said biasing means have been removed from the handle and placed inside a hand grip 30 . The hand grip 30 , may be constructed in any form which could be stored securely on the embodiment of the shovel for easy access. The general circular shape of the embodiment 28 must be suitable for spooling the return line 40 , through an egress 31 , within a reel for winding up or winding out using any suitable channel 27 , interposed of a return line located within the said grip 30 , using any method commonly known to those experienced in the art.
[0041] It will be understood from the preceding description that a return line including a biasing means, and tethering means, or other intermediary components in combination with a grip and holder, could be placed at any point on the shovel, not necessarily in the primary handle 1 , of FIG. 3, but also within the scoop 2 .
[0042] It will also be understood that the preceding description of the preferred embodiments of the present invention is for the purposes of illustration only and that the various structural and operational features herein described are susceptible to modifications none of which entails departure from the scope and spirit of the present invention herein disclosed
|
This invention describes an extensible grip having a return line to facilitate the extending and retracting of a tethered grip of an ergonomic shovel in accordance with prior art for stand-up shovels using a flexible tether and biasing means. A pocket or frame structure is described for disposition of the retracted auxiliary grip to facilitate storage.
| 4
|
The subject matter of this application is related to the subject matters of applicants' copending applications, Ser. No. 813,624, filed July 7, 1977, and Ser. No. 813,626, filed July 7, 1977, which are assigned to the assignee of this application.
BACKGROUND OF THE INVENTION
The present invention relates to a motor control system for a sewing machine in which thyristors are employed for motor driving control. More particulary, the invention relates to a one stitch sewing control system for a sewing machine in which thyristors are employed for motor driving control.
A conventional motor control system for one stitch sewing, in which the motor is energized by selection of the one stitch sewing mode and downward force on the foot controller and stops after execution of the one stitch sewing operation, employs either a mechanical control means such as a one way clutch and stopper, or an electric control circuit which controls energization and deenergization of the motor in accordance with the movement of the sewing needle. The mechanical control means correctly controls the one stitch sewing. However, it has many mechanical components and produces mechanical impact shock and noise. Therefore it may be worn out after a relatively short life. Energization and deenergization of the motor by an electric circuit for one stitch sewing control also has some defects; stop control is relatively rough in high speed one stitch sewing, and motor speed should be low to stop the sewing needle correctly at a predetermined halt position after completion of a stitch.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a motor control system for one stitch control of a sewing machine, which is compact and comprises a relatively small number of mechanical elements.
A further object of the present invention is to provide a motor control system for one stitch control of a sewing machine, which controls motor speed so as to stop the sewing needle at a predetermined halt position quickly and correctly in the one stitch sewing control mode.
Other objects of the invention will be apparent from the detailed description of the invention described hereinafter, referring the attached drawings.
According to the present invention, a motor control system for a sewing machine which comprises motor drive thyristors, a trigger phase control circuit for controlling the operation of the motor drive thyristors and a comparator circuit for generating a trigger phase indication signal to accelerate or decelerate motor speed to an indicated speed which corresponds to downward force on a foot controller further comprises, according to the present invention, a start detection circuit, first and second needle position detectors, first and second memory circuits, a one stitch sewing speed indication signal generator circuit and a predetermined constant trigger phase command signal generator circuit.
The start detection circuit generates a pulse when the one stitch sewing mode is selected and the foot controller is forced down to operate one stitch sewing. The first memory circuit is energized by the pulse and energizes the one stitch sewing speed indication signal generator circuit which in turn supplies a one stitch sewing speed indication signal to the comparator circuit. Therefore the motor drive thyristors are triggered to turn ON at a predetermined phase angle which corresponds to the one stitch sewing indication signal. Thus the motor will be energized to rotate at a predetermined higher speed. The first detector means detects the arrival of the sewing needle at the lowered halt position and deenergizes the first memory circuit to deenergize the one stitch sewing speed indication signal generator circuit, deenergization of which causes energization of the second memory circuit to energize the predetermined constant trigger phase command signal generator circuit. Then a constant trigger phase command signal is applied to the comparator circuit to drive the motor at another predetermined constant speed which is low enough to allow the sewing needle to be smoothly stopped at the raised halt position. At the raised position of the sewing needle, the second needle position detector detects it and deenergizes the predetermined constant trigger phase command signal generator circuit, deenergization of which causes a brake command signal to be applied to a brake means. Thus the sewing needle stops at the raised halt position after one stitch sewing. The first speed of the motor, until the sewing needle arrives at the lowered halt position, may be predetermined at a high level by the one stitch sewing speed indication signal. The second speed of the motor, after the sewing needle arrives at the lowered halt position, may be predetermined at a low enough level to decelerate the motor's speed before the sewing needle comes to the raised halt position by the predetermined constant trigger phase command signal. Therefore the sewing needle starts to move at a relatively high speed and then it is decelerated to stop relatively smoothly and correctly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a preferred embodiment of the present invention;
FIG. 2a is a graph which shows the relationship between motor speed and the motor speed signal at the connecting point (cl) denoted in FIG. 1;
FIG. 2b is a graph which shows the relationship between downward force on the foot controller and the resistance value of the variable resistor in the foot controller;
FIG. 2c is a graph which shows the relationship between downward force on the foot controller and the motor speed indication signal at the connecting point (a) denoted in FIG. 1;
FIG. 2d is a graph which shows the relationship between downward force on the foot controller and motor speed;
FIG. 3, FIG. 4 and FIG. 5 show signal waveforms at various points in FIG. 1, in which time axes are equivalent;
FIG. 6 shows signal waveforms at various points in FIG. 1 when the foot controller is forced down;
FIG. 7 and FIG. 8 show signal waveforms at various points in FIG. 1 when the foot controller is adjusted;
FIG. 9 shows the relationship between the trigger phase of the motor drive thyristors and energy supplied to the motor; and
FIG. 10, FIG. 11 and FIG. 12 show operational timing of some parts of the circuit shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a preferred embodiment of the invention, which comprises circuit means for motor speed control, predetermined halt position control of the sewing needle, and one stitch sewing control. There is a variable resistor A in the foot controller. The variable resistor A comprises resistor 1 and slider 2 which moves in correspondance with downward force on the foot controller by an operator. The slider 2 touches contact 3a when the foot controller is not forced down by the operator (stop position). Assuming that the foot controller is depressed by the operator, the slider 2 at first touches contact 3b, then touches resistor 1, and at last touches contact 4 (motor drive position). Motor unit B comprises a rotor or armature 5, stator or field winding 6, and diodes 7 and 8. The field winding 6 is serially connected with armature 5. The diode 7 is connected in parallel with armature 5 so as to discharge the counter electromotive voltage in armature 5 when the source voltage to motor unit B is interrupted. The diode 8 is connected in parallel with filed winding 6 so as to discharge the counter electromotive voltage in field winding 6 when the source voltage to motor unit B is interrupted. Diodes 9, 10, 11 and 12 are connected to the AC voltage source through lines 13 and 14a in full wave rectifier form. The negative output line 18 from the diode full wave rectifier 9, 10, 11 and 12 is assumed to have a voltage reference level of zero. The positive output line from the diode full wave rectifier 9, 10, 11 and 12 is connected to the anode of diode 14b, which constitute a simple voltage regulator circuit with resistor 15, Zener diode 16 and capacitor 17. The positive voltage terminal of capacitor 17 supplies a constant voltage V to positive voltage line 19.
An FET (Field Effect Transistor) 20 is connected to negative voltage line 18. Constant current is made to pass through drain D and source S of FET 20 by connecting gate G to source S and supplying a voltage which is above a predetermined threshold level between drain D and source S. Thus FET 20 operates as a constant current source. The drain S of FET 20 is connected to the positive constant voltage line 19 through the first mode selector switch M, contact 4, resistor 1 and slider 2. By this connection, the voltage drop between contact 4 and slider 2, and the voltage available at the first mode selector switch M is proportional to the position of slider 2 because of the constant current limitation of FET 20. When the foot controller is depressed gradually by an operator, the position of the slider 2 gradually approaches contact 4 and the resistance between slider 2 and contact 4 decreases gradually. This relationship is shown in FIG. 2b. The voltage at drain S of FET 20, i.e. the voltage at connecting point (a), corresponds to the resistance between slider 2 and contact 4. Thus the voltage at connecting point (a) changes in correspondance with the downward force on the foot controller, as shown in FIG. 2c. The voltage at connecting point (a) is the motor speed command signal, which will be described as the "motor speed indication signal". If the resistance distribution of the resistor 1 is not linear and/or movement of slider 2 is not linear in relation to downward force on the foot controller, the resistance value between slider 2 and contact 4, as well as the voltage at connecting point (a), will not be proportional to downward force on the foot controller, as shown by the dotted lines and phantom lines. Thus the acceleration and deceleration characteristics of motor control may be adjusted by changing the resistance distribution of resistor 1, movement of slider 2, and/or inserting another resistance between contact 4 and connecting point (a).
Motor drive control thyristors 21 and 22 are serially connected to motor unit B through diode 23. Thyristors 21 and 22 control the AC power provided to motor unit B in correspondance with the gate trigger signals. Thyristors 21 and 22 alternatively control the conduction phase of half wave AC power. The voltage waveforms at the cathode of thyristors 21 and 22 (i.e., at the anode of diode 23) are shown in FIG. 3. Voltage waveforms (a) and (b) in FIG. 3 represents the operation of thyristors 21 and 22 respectively. The voltage waveform at the cathode of diode 23 is shown in FIG. 4. The waveform at the cathode of diode 23 differs from the waveform at the anode of diode 23. The different parts l of the cathode waveform of diode 23 are caused by discharge of electromagnetic energy stored in field winding 6 when thyristors 21 and 22 conduct. The discharge through diode 8 provides a field current for field winding 6 for a short time interval, during which motor unit B operates as a generator. The generated output voltage is proportional to revolution speed. Thus the voltage level of the parts l, at the cathode of diode 23, corresponds to motor speed.
The voltage at the anode of diode 23 is supplied to a thyristors ON detection circuit which comprises resistors 24 and 25, capacitor 26 and NPN transistor 27. NPN transistor 27 is controlled by the cathode voltage of thyristors 21 and 22. Therefore NPN transistor 27 turns ON when thyristors 21 and 22 turn ON, and OFF when they turn OFF. The voltage at the cathode of diode 23 (FIG. 2) is supplied to a motor speed detection circuit which comprises diode 28, resistors 29 and 31, capacitor 32 and diode 33b. Capacitor 32 smoothes the input voltage through resistor 29. Either resistor 31 or 177 is connected to resistor 29 through the second mode selector switch N. Thus the voltage across capacitor 32 shows a mean proportional to the cathode voltage of diode 23. The positive terminal of capacitor 32 is connected to the collector of NPN transistor 27 through diode 33b. NPN transistor 27 is controlled by the output voltage of thyristors 21 and 22, as described herein before, and therefore the voltage waveform at the positive terminal (connection point cl) of capacitor 32 is proportional to parts l at the cathode of diode 23, as shown in FIG. 5. The voltage level at the connection point cl (FIG. 5) is thus proportional to motor speed, the relationship being shown in FIG. 2a. Selection of the second mode selector switch N and/or adjustment of resistor 31 or 177 will change the proportional ratio of the voltage in relation to motor speed, as shown by (a) and (b) in FIG. 2a. Curve (a) corresponds to closure of switch 30 and selection of contact N-1 of mode selector switch N. Curve (b) results when switch 30 is open and contact N-1 of mode selector switch N is selected.
The input voltage to differencial or operational amplifier (hereinafter analog IC) 33a, from connection point cl through resistor 36, is adjusted by a potential divider which comprises resistors 35, 37 and 38. The voltage at connection point (a) is also supplied to analog IC 33a through resistor 34. Thus one of the inputs to analog IC 33a is the motor speed signal (FIG. 5) from connection point cl, and the other input is the motor speed indication signal (FIG. 2c) from connection point (a). Variable resistor 38 is adjusted so that the sum of the voltage at connection point (b) and the voltage at connection point cl (when the motor is stopped and slider 2 is at contact 3a) is greater than the voltage at connection point (a), and so that the former is less than the latter when slider 2 is at contact 3b.
The analog IC 33a is a comparator. The motor speed signal from connection point cl is supplied to the plus terminal of analog IC 33a, and the motor speed indication signal from connection point (a) is supplied to the minus terminal of analog IC 33a. The output of analog IC 33a is at the zero level when the motor speed indication signal level is greater than the motor speed signal level, and a positive voltage V when the former is less than the latter.
A trigger phase indication circuit, which comprises resistors 39 and 40, diodes 41 and 42, capacitor 43, resistors 44 and 45, transistor 47 and diode 46, controls the charging and discharging of capacitor 43 in correspondance with the output of analog IC 33a. The voltage across capacitor 43 controls the phase angle (of the AC power source) at which thyristors 21 and 22 are triggered, or the "trigger phase" of thyristors 21 and 22, as described hereinafter. Capacitor 43 is discharged through resistor 40 and diode 42 when the output of analog IC 33a, is at the zero level (the motor speed indication signal level is higher than the motor speed signal level), and the capacitor 43 is charged up through resistor 39 and diode 41 when the output of analog IC 33a is a positive voltage V. Thus, the voltage across capacitor 43 changes in accordance with the output level of analog IC 33a. The charging circuit (resistor 39 and diode 41) and discharging circuit (resistor 40 and diode 42) for capacitor 43 are different from each other so as to provide different time constants for charging and discharging capacitor 43 and thus accommodate trigger phase control with motor speed fluctuations caused by load fluctuation of the sewing machine. Thus, control of motor speed will be smooth. A circuit having PNP transistor 47, resistors 44, 45 and diode 46 compensates for the zero voltage interval of the motor speed signal (FIG. 5) and prevents capacitor 43 from discharging during the zero voltage interval of the motor speed signal. PNP transistor 47 turns ON when thyristors 21, 22 and transistor 27 turn ON. At this time, the cathode voltage of diode 42 rises to voltage V, which prevents the discharge of capacitor 43. The output terminal of analog IC 33a is connected to resistors 39 and 40, which in turn are connected to the anode of diode 40 and cathode of diode 42, respectively. The anode of diode 42 is connected to the cathode of diode 41 and capacitor 43. Capacitor 43 is also connected to the zero level line 18. The cathode of diode 42 is connected to the collector of PNP transistor 47 through diode 152a. The emitter of PNP transistor 47 is connected to the positive constant voltage line 19, and the base terminal is connected to resistors 44 and 45. Resistors 44 and 45 are also connected to line 19 and the anode of diode 46 respectively.
A saw-tooth oscillator circuit, which comprises diode 57, resistors 74 and 75, transistor 78, resistors 76 and 77, transistor 79, resistor 49 and capacitor 50, is energized by AC power and generates a saw-tooth wave voltage in synchronism with the AC frequency, as shown in FIG. 7, (b). The saw-tooth wave voltage has a zero level interval which corresponds to conduction of thyristors 21 and 22 as well as transistor 27. The waveform shown in FIG. 7, (b) is at connection point (f), which is the output terminal of the saw-tooth oscillator circuit. Transistor 78 turns ON and OFF in synchronism with the AC voltage and transistor 79 turns OFF and ON in the reverse mode as compared with transistor 79. Capacitor 50 is charged through resistor 49 and discharged when transistor 79 turns ON. Moreover, the capacitor 50 is discharged through diode 57 and transistor 27.
Resistors 51 and 52 are serially connected between lines 18 and 19. The intermediate connecting point (d) between resistors 51 and 52 is connected to connection point (e) through resistors 54 and 55. This connection provides capacitor 43 and analog IC 53 with a bias voltage. Analog IC 53 is a comparator to which the voltages at capacitors 43 and 50 are supplied. Resistors 54, 55 and 56 limit the electric current to analog IC 53. The minus input terminal of analog IC 53 is connected to resistors 54 and 55, and the plus input terminal is connected to resistor 56. Resistor 54 is connected to lines 19 and 18 through resistor 51 and variable resistor 52 respectively. Resistors 55 and 56 are connected to connection points (e) and (f) respectively. The output of analog IC 53 is a zero level voltage when the voltage at the minus terminal exceeds that of the plus terminal, and a positive voltage V when the former is less than the latter.
Resistors 58 and 59, NPN transistor 60, pulse transformer 61, diodes 63 and 64 and resistors 65, 66, 67 and 68 form a trigger circuit for control of thyristors 21 and 22. Transistor 60 is turned ON by a positive output voltage from analog IC 53, and current is supplied to the primary coil 61-a of pulse transformer 61. This produces a pulse voltage in secondary coil 61-b. This pulse voltage is rectified by diodes 63 and 64, regulated by resistors 65 and 66, and then supplied to the gates of thyristors 21 and 22, which are turned ON by the pulse. Turning thyristors 21 and 22 ON causes transistor 27 to conduct, which causes capacitor 50 to discharge and produces a fall in the output voltage of analog IC 53. Thus, transistor 60 turns OFF. Thus transistor 60 interrupts the current in the pulse transformer 61.
A safety circuit, comprising PNP transistor 69, resistor 70, capacitor 71 and diode 72, controls the input signal to analog IC 53. Without this circuit, thyristors 21 and 22 would turn ON and motor unit B would be energized when the AC power is turned ON, because the voltage at connection point (f) would rise faster than the voltage at connection point (e) and therefore the output voltage of analog IC 53 would rise quickly. The safety circuit prevents this undesirable operation of analog IC 53. Transistor 69 is conductive during the time constant of resistor 70 and capacitor 71, and supplies the positive voltage of line 19 to analog IC 53. The time constant of resistor 70 and capacitor 71 is predetermined so as to prevent undesirable operation of analog IC 53. Capacitor 71 is discharged through diode 72 when the AC power source is disconnected.
Pulse generator circuits are formed by resistor 101, capacitor 102 and diodes 103 and 104, by resistor 105, capacitor 106 and diodes 107 and 108, and by resistor 109, capacitor 110 and diodes 111 and 112. These pulse generator circuits produce a positive pulse of a predetermined width when resistors 101, 105 and 109, respectively, receive a positive voltage. A positive pulse appears through diode 104 when slider 2 touches contact 3a, a positive pulse appears through diode 108 when the third mode selector switch K is set at contact K-2, and a positive pulse appears through diode 112 when the third mode selector switch K is set at contact K-1.
The start detection circuit, which includes transistor 114, resistor 115, capacitor 116, and diode 117, is a pulse generator circuit which generates a positive pulse of a predetermined width when the base potential of transistor 114 falls to the zero level. This indicates that slider 2 has moved from contact 3a to resistor 1. The emitter of transistor 116 is connected to contact K-3 of the third mode selector switch K. The base is connected to contact 3a and resistor 101.
The third mode selector switch K supplies electric current to those pulse generator circuits as described above.
Diodes 118 and 119 interrupt backward flow and supply emitter current to transistor 120.
Transistors 120 and 121, diodes 122 and 123, resistors 124, 125 and 126, thyristor 127 and capacitor 128 form the timer circuit, which receives a positive pulse from the diodes 122 and 123 and turns transistor 120 OFF after a predetermined delay time (the discharge constant of capacitor 128). The anode of diode 122 is connected to the cathode of diode 117, and the anode of diode 123 is connected to resistor 113. The cathodes of diodes 122 and 123 are connected to the base of the transistor. The collector of transistor 121 is connected to line 19 and the emitter is connected to the gate of thyristor 127 through resistor 124. Resistor 125 is connected between line 18 and the gate of thyristor 127. The anode of thyristor 127 is connected to capacitor 128, and is also connected to the base of transistor 120 through resistor 126. The cathode of thyristor 127 and capacitor 128 are connected to line 18. The collector of transistor 120 is connected to the anode of the diode 129 as well as resistor 130.
The braking circuit comprises resistor 130, diodes 131 and 183, Zener diode 132, and resistors 133 and 134, as well as shunt thyristor 135. The motor unit B generates a dynamic braking force when the shunt thyristor turns ON. Zener diode 132 prevents low level error voltage from reaching the gate of shunt thyristor 135. Zener diode 132 breaks down only when shunt loops through diodes 129, 131 and 132 are interrupted, and triggers shunt thyristor 135. This interruption is controlled by the brake command circuit hereinafter described.
Transistor 136, resistors 137 and 138 and diode 178 form the "trigger phase clamp circuit," which produces a signal for triggering thyristors 21 and 22 at the appropriate phase angle (of the AC power source) when the motor is being stopped. Transistor 136 turns ON when Zener diode 132 breaks down. At this time the brake command signal appears at resistor 133. Turning transistor 136 ON shunts the charging circuit for capacitor 43. Thus capacitor 43 stops charging and the voltage across capacitor 43 remains constant. This causes a constant phase trigger pulse at pulse transformer 61.
Diode 139, resistor 140, capacitor 141, diode 142, resistors 143 through 146, analog IC 147, resistors 148 through 150 and transistor 151 form the deceleration detector circuit. Analog IC 147 is a comparator, and its inputs are the motor speed signal at connection point c2 and the predetermined reference voltage at connection point (h). The voltage at connection point c2 (capacitor 141) is proportional to the motor speed signal at connection point c1, because diode 139, resistor 140 and capacitor 141 correspond to diode 28, resistor 29 and capacitor 32 respectively. The analog IC 147 turns transistor 151 ON when the voltage at connection point c2 exceeds that of connection point (h). Namely transistor 151 turns ON when motor speed is over a predetermined value, and turns OFF when motor speed is under the predetermined value, which may be adjusted by variable resistor 146. The output of analog IC 147 is at the zero level when the voltage at connection point c2 exceeds the voltage at connection point (h). However, as described herein before, the voltage at connection point c2 falls by virtue of diode 142 when motor drive thyristors 21 and 22 as well as transistor 27 turn ON. Therefore the output voltage of analog IC 147 falls to the zero level even if the speed of the motor is higher than the predetermined value. To prevent this undesirable operation, the collector of transistor 47 (connection point i) is connected to the output of analog IC 147. The collector voltage of transistor 47 rises only when transistor 27 turns ON, as shown in FIG. 11. This prevents undesirable operation of transistor 151.
Diode 152a prevents backward flow of discharge current from capacitor 43 to resistors 148 and 149 through diode 42.
The first, second and third reed switches 153, 154 and 152 are the normally closed type, and they open when permanent magnets approach them. The third reed switch 152 is employed for thread winding detection. When the bobbin winding mechanism is operated, the reed switch 152 is opened. The first and second reed switches 153 and 154 are employed for the needle position detector means. The first reed switch 153 is opened, when the sewing needle comes to the lowered halt position, by a permanent magnet which rotates or moves in synchronism with the movement of the sewing needle. The second reed switch 154 is opened, when the thread take-up lever or the sewing needle comes to the raised halt position, by a permanent magnet which rotates or moves in synchronism with the movement of the thread take-up lever or the sewing needle. The first and second reed switches 153 and 154 are connected to the cathode of thyristor 166 through the fourth mode selector switch L. The third reed switch 152 is connected between line 18 and reed switches 153 and 154.
A first memory circuit, which comprises thyristor 155, resistors 156, 157 and 158, capacitor 159, Zener diode 160, and diode 161, clamps the potential at connection point (j) to the zero level during the time interval between the appearance of a pulse (stop signal) from capacitor 116 and the opening of reed switch 153. Zener diode 160 passes the pulse from capacitor 116 to the gate of thyristor 155, and thereby prevents an undesirable signal or voltage from reaching the gate of thyristor 155. Capacitor 159 absorbs noise or error signals and prevents thyristor 155 from conducting at an undesirable time. The cathode of thyristor 155 is connected to reed switch 153 through the fourth mode selector switch L. Therefore thyristor 155, once triggered by the pulse from capacitor 116, continues conducting until serially connected reed switch 153 opens.
The change over pulse generator circuit, comprising capacitor 162, resistor 163, diodes 164 and 165, generates a positive pulse of predetermined width when thyristor 155 turns OFF and the voltage at connection points (j) rises to the positive level of line 19. The positive pulse is supplied to resistor 113 through diode 165.
A second memory circuit, which comprises thyristor 166, resistors 167, 168 and 169, and capacitor 170, clamps the potential at connection point (k) to the zero level during the time interval between the appearance of a pulse from either diodes 104, 108, 112 or 165 and the opening of reed switches 153 or 154 or the turning OFF of transistor 151. Capacitor 170 absorbs noise signals and prevents undesirable conduction of thyristor 166. The cathode of thyristor 166 is connected to common contact L-O of the fourth mode selector switch L and to the collector of transistor 151.
The braking circuit (130-132) described above, the first memory circuit (155-161), and the second memory circuit (166-170) form the brake command circuit in this embodiment, as shown in FIG. 1.
The first switch circuit, having transistor 171 and resistors 172 and 173, is the one stitch sewing speed indication signal generator circuit. It is turned ON by conduction of thyristor 155. Thus a voltage drop appears across resistor 173 when thyristor 155 conducts. The base of transistor 171 is connected to connection point (j) through resistor 172.
The second switch circuit, having transistor 174, and resistors 175 and 176, is the predetermined constant trigger phase command signal generator circuit, in which a voltage drop appears across resistor 176 when thyristor 166 turns ON. The emitter of transistor 174 is connected to line 18, and the collector of transistor 174 is connected to the drain of FET 20 through resistor 176. The base of transistor 174 is connected to the anode (k) of thyristor 166. The predetermined constant trigger phase command signal generator circuit, together, with the first mode selector switch M as well as FET 20, governs motor speed. The voltage at connection point (a) corresponds to the resistance between slider 2 and contact 4 when contact M-1 or M-2 in the first mode selector switch M is selected. The voltage at connection point (a) corresponds to the resistance of resistor 173 when contact M-3 in the switch M is selected, and it corresponds to the resistance of resistor 173 when slider 2 is at contact 3a and transistors 171 and 174 are OFF and ON respectively. Contacts M-1 and M-2 of the first mode selector switch M are connected to contact 4 of variable resistor 1, and contact M-3 is connected to resistor 173. Common contact M-0 of the switch M is connected to the drain of FET 20.
The second mode selector switch N is used for selecting the appropriate voltage divider network for the motor speed feedback voltage (motor speed signal). This motor speed signal is supplied to capacitor 32. The common contact N-0 of the second mode selector switch N is connected to the cathode of diode 28 through resistor 29. Contacts N-1 and N-2 of the switch N are connected to variable resistor 31. Contact N-3 is connected to variable resistor 177. Resistors 31 and 177 are connected to line 18.
The first, second, third and fourth mode selector switches M, N, K and L are interconnected to be operated in synchronism. Thus if contact K-1 is selected in the third mode selector switch K, contacts M-1, N-1 and L-1 are selected at the same time in the first, second and fourth mode selector switches M, N, and L respectively. In the first position, the first contacts K-1, L-1, M-1 and N-1 are selected. This first position corresponds to a command to stop the sewing needle at the lowered halt position. In the second position, the second contacts K-2, L-2, M-2, and N-2 are selected. This second position corresponds to a command to stop the thread take-up lever or the sewing needle at the raised halt position. In the third position, the third contacts K-3, L-3, M-3 and N-3 are selected. This third position corresponds to a command to perform one stitch sewing, in which the thread take-up lever, after the foot controller is forced down, moves from its raised halt position to the lowered halt position, then returns to the raised halt position and stops.
Resistors 179 and 180, capacitor 181 and transistor 182 form a discharge circuit for capacitor 71. Transistor 182 turns ON and discharges capacitor 71 within a predetermined time interval when transistor 136 turns OFF and capacitor 181 is being charged. Resistor 179 is connected between line 19 and the collector of transistor 136. The collector and emitter of transistor 182 are connected with capacitor 71 and line 18 respectively. The base of transistor 182 is connected to the collector of transistor 136 through capacitor 181. The base and the emitter are connected to resistor 180.
The construction of the preferred embodiment shown in FIG. 1 has now been described. Operation of the preferred embodiment will be described hereinafter.
First, we assume that an AC power voltage is supplied to lines 13 and 14a, that the foot controller is not forced down and slider 2 touches contact 3a, that the first, second, third and fourth mode selector switches M, N, K and L are set at the first position (contacts M-1, N-1, K-1 and L-1 are selected to stop the sewing needle at the lowered halt position), that the third reed switch 152 is closed (this means that the sewing machine is prepared to operate in the sewing mode. Only in the bobbin winding mode will the reed switch 152 be opened.), that the sewing needle is at the lowered halt position and that the motor is at a standstill. Under these assumptions, the voltage level at connection point (a) is zero, because the resistance between line 19 and drain D of FET 20 is infinity. The voltage level at connection point c1 is zero, because the motor is at a standstill. The voltage level at connection point (b) is a predetermined value, which is adjusted by varying resistor 38 so as to operate motor unit B at the minimum motor speed when slider 2 touches contact 3b. Therefore, the sum of the voltages at connection point (b) and c1 exceeds the voltage at connection point (a). FIG. 8(a) shows voltage levels at connection points (a), (b), and c1. The output voltage of analog IC 33a (comparator) is a constant level V. Thus capacitor 43 is charged through resistor 39 and diode 41. The voltage across capacitor 43 (at connection point e) when it is charging is shown in FIG. 8 (b). the voltage across capacitor 43 will be a constant level V after a predetermined time constant which relates to the resistance of resistor 39 and capacitance of capacitor 43. The Input to the minus terminal of analog IC 53 corresponds to Ve+d, which indicates the sum of the saturated voltage level Ve across capacitor 43 and the voltage level at connection point (d). A saw-tooth wave voltage synchronized with the AC power frequency is constantly supplied to the plus terminal of analog IC 53. Resistor 49 and capacitor 50 are preliminary selected so as to obtain the relationship Ve+d>Vf, wherein Vf indicated the peak level of the saw-tooth wave voltage. The relationship between Ve+d and Vf is shown in FIG. 7(b). By this relationship, the output voltage of analog IC 53 is at the zero level. Thus the pulse transformer is not energized. Thyristors 21 and 22 are not triggered. Motor unit B is electrically separated from the AC power lines 13 and 14a by thyristors 21 and 22. Thus motor unit B is at a standstill.
Second, we assume that the foot controller is forced down slightly and slider 2 touches contact 3b. According to the change of resistance R between slider 2 and contact 4 (FIG. 2b), the voltage at connection point (a) is equal to (V-R·i), wherein V indicates the voltage level of line 19 and i indicates the constant current value which flows in FET 20. The voltage level at connection point (a) is shown in FIG. 2c. Variable resistor 38 is preliminarily adjusted such that the voltage level at connection point (a) exceeds the voltage level at connection point (b) when slider 2 touches 3b. The voltage level at connection point c1 is zero when motor unit B is at a standstill. When slider 2 touches contact 3b, the output voltage of analog IC 33a is at the zero level because the voltage level at connection point (a) exceeds the sum of the voltage levels at connection points (b) and c1. Capacitor 43 discharges through diode 42 and resistor 40, and the voltage level at connection point (e) falls gradually. Thus the sum of the voltage levels at connection points (b) and c1 falls gradually. This causes the time interval in which the voltage level at connection point (f) exceeds the sum of the voltage levels at connection points (b) and c1, as shown in FIG. 7, (b). During this time interval, the output voltage level of analog IC 53 increases to V, which energizes pulse transformer 61. Thyristors 21 and 22 are triggered by the output pulse of transformer 61. Thyristors 21 and 22 thus turn ON and maintain the ON state until the AC power voltage returns to zero level. Motor unit B is energized through thyristors 21 and 22. Rotation of armature 5 generates a voltage at connection point c1. The voltage at point c1 corresponds to motor speed. At the start of motor rotation, the sum of the voltage levels of connection points (b) and c1 is less than the voltage at connection point (a) because of low speed of the motor. This is shown as an interval T 1 in FIG. 6. In this interval T 1 capacitor 43 is still discharging and the voltage level at connection point (e) is falling. This causes the summed voltage level of connection points (e) and (d) to fall. Therefore the trigger phase of thyristors 21 and 22 leads, that is to say, the thyristors are triggered at a smaller phase angle relative to the AC supply, so that power is available to motor unit B for a larger portion of the time during each cycle of AC power. The energization time interval within a half wave of AC power is prolonged to speed up the motor. Speeding up the motor raises the voltage level at C1, by which the sum of the voltage levels at connection points (b) and c1 rises and then keeps constant, as shown by interval T 2 in FIG. 6. When the voltage at connection point c1 is constant (and also voltage level of point (e) is constant), the motor rotates with a constant speed. The sum voltage level Ve+d corresponding to connection points (e) and (d), as well as the ON, OFF condition of thyristors 21 and 22 are shown in FIG. 7. The sum voltage level Ve+d corresponding to connection points (e) and (d) falls in correspondance with the movement of slider 2 from contact 3a to 3b.
The motor speed signal is not present when thyristors 21 and 22 are turned ON. Therefore discharge of capacitor 43 is interrupted and the voltage level at connection point (e) is clamped during the turn-ON interval of thyristors 21 and 22 as shown in FIG. 6, (b). This interruption of discharge is obtained from the turn-ON operation of transistor 27, which is controlled by the cathode voltage of thyristors 21 and 22. Capacitor 32 discharges and transistor 47 turns ON when transistor 27 turns ON. Thus the output voltage of analog IC 33a falls to the zero level (interrupting the charging of capacitor 43), and a positive voltage V is supplied to the cathode of diode 42 to prevent discharging of capacitor 43.
Trigger pulses from pulse transformer 61 are not required during the time interval after turn-ON of thyristors 21, 22 and before the AC power voltage falls to zero level. Capacitor 50 discharges at the time when transistor 27 turns ON, by which the voltage of connection point (f) and output terminal of analog IC 53 fall to zero level to interrupt conduction of transistor 60. Thus energization of transformer 61 is prevented during the turn-ON of thyristors 21 and 22. As a result the actual voltage level at connection point (f) pulsates as shown by the dotted line in FIG. 7, (b) providing that slider 2 touches contact 3b.
Third, we assume that the foot controller is forced down deeply and slider 2 touches resistor 1. The voltage level at connection point (a) rises in correspondance with downward force on the foot controller, as shown in FIG. 2c, because slider 2 moves toward contact 4 by the downward force. This means that the motor speed indication signal exceeds the actual motor speed. Then the output voltage of analog IC 33a falls to zero level and capacitor 43 discharges. This condition corresponds to the signal level relationship as shown in interval T 1 in FIG. 6. At this time the sum Ve+d of the voltage levels corresponding to connection points (e) and (d) falls below the voltage level Vf at connection point (f), which causes the trigger phase of thyristors 21 and 22 to lead and thereby increases the time during which the thyristors are triggered. Thus the motor is accelerated and the voltage level at connection point c1 rises. Then the trigger phase of thyristors 21 and 22 lags and finally the motor will rotate at a balanced constant speed according to the position of slider 2. Release of the foot controller, i.e. movement of slider 2 toward contact 3b, decreases the voltage level at connection point (a). Then the voltage level at connection point c1 exceeds that of point (a), as shown in interval T 3 in FIG. 6. The output of analog IC 33a rises up to a positive level V and charges capacitor 43. The voltage level at connection point (e) rises. Therefore, the sum voltage level Ve+d corresponding to connection points (e) and (d) exceeds the voltage level Vf at connection point (f), by which the trigger phase of thyristors 21 and 22 lags. This causes deceleration of the motor, and the voltage level at connection point c1 falls. And, finally the motor will rotate at a balanced constant speed which corresponds to the new position of slider 2.
As described above, the voltage level at connection point (a) corresponds to the position of slider 2, i.e. the downward force on the foot controller. The trigger phase of thyristors 21 and 22 leads or lags in correspondance with the difference between the voltage levels at connection points (a) and c1. In other words, the trigger phase of the thyristors is automatically controlled so as to balance the actual motor speed with the motor indication speed. Since the voltage level at connection point c1 is proportional to actual motor speed, as shown in FIG. 2a, and since the trigger phase control is continued until the voltage at connection point (c) is equivalent to the voltage at connection point (a), the actual motor speed is proportional to the voltage level at connection point (a). Also the voltage at connection point (a) is proportional to the resistance between slider 2 and contact 4. Consequently, the relationship between downward force and motor speed as shown in FIG. 2d can be attained by adjusting the connection between slider 2 and the foot controller pedal.
Fourth, we assume that the load on the motor fluctuates. When the motor rotates at a constant speed and the load is constant, the voltage levels at connection points (a), c1 and (e) are constant (T 2 mode in FIG. 6). When the load on the motor is increased, at first the motor decelerates and the voltage level at connection point c1 falls. Therefore the voltage level at connecting point (a) exceeds the voltage at connecting point c1, as shown in interval T 1 in FIG. 6, and the trigger phase of thyristors 21 and 22 leads. Motor unit B receives increased energy in response to the increased load. Then the speed of the motor recovers. When the motor load is too heavy to recover to the proper speed, the voltage level at connection point (e) finally falls to zero to lead the trigger phase of thyristors 21 and 22 to the most advanced electric phase angle, at which almost the full AC power is supplied to motor unit B. This means that the largest possible torque is produced even if indicated motor speed set by the position of slider 2 is the predetermined lowest one. On the other hand, if the load on the motor were lightened, the speed would rise and the voltage level at connection point c1 would increase, as shown in interval T 3 in FIG. 6. Therefore the trigger phase of thyristors 21 and 22 would lag to decelerate the motor until it achieves a speed which corresponds to the voltage level at connection point (a).
The safety circuit, comprising transistor 69, resistor 70, capacitor 71 and diode 72, prevents undesirable rotation of motor when AC power is supplied. If the foot controller is released completely, slider 2 touches contact 3a, and AC power is applied, then capacitor 43 and capacitor 50 begin to charge up because the output of analog IC 33a rises to voltage level V. After capacitor 43 is fully charged, the sum of the voltage levels corresponding to corresponding to connection points (e) and (d) exceeds the voltage level at connection point (f); i.e. Ve+d>Vf, so that pulse transformer 61 is not energized. However, Vf may exceed Ve+d when capacitor 43 is charging because the time constant of the charging circuit for capacitor 43 is larger than that for capacitor 50, and the transformer may be energized to trigger thyristors 21 and 22 and thereby energize motor unit B. To prevent this, transistor 69 is biased to turn ON during a time interval which corresponds to the time constant of resistor 70 and capacitor 71. The voltage level at connection point (d) is kept at a positive level V when transistor 69 is turned ON. Thus Ve+d>Vf and motor unit B is not energized when AC power is applied. Capacitor 71 discharges quickly through diode 72 when AC power is removed. Therefore, transistor 69 can turn ON the next time AC power is applied.
Fifth, we assume that the first, second, third and fourth mode selector switches K, L, M and N are set at the first position to stop the sewing needle at its lowered halt position (contacts M-1, N-1, K-1 and L-1 are selected), that the sewing machine is to be operated in the sewing mode (reed switch 152 is closed), and that the foot controller is released and slider 2 comes back to contact 3a. When slider 2 touches contact 3a the trigger pulse generator circuit, comprising resistor 101, capacitor 102, and diode 103, generates a pulse of a predetermined width and supplies it to resistor 113 through diode 104. Then transistor 121 and thyristor 127 turn ON. This discharges capacitor 128. The discharge of capacitor 128 causes transistor 120 to turn ON, and it continues conducting until capacitor 128 is charged up to voltage level V. When transistor 120 conducts, connection points (k) and (j) are connected to line 19 through diods 129, transistor 120, diode 118, contact 3a and slider 2. Thyristor 166 is also triggered by the pulse from the trigger pulse generator circuit and turns ON. Therefore the voltage level at connection point (k) falls to the zero level through thyristor 166 and transistor 151, providing that motor speed is over a predetermined braking threshold level (intervals V and W shown in FIG. 10). By this, the cathode of Zener diode 132 falls to the zero level through diode 131. Thyristor 135 is not triggered and transistor 174 turns ON. Therefore resistor 176 is connected to connection point (a) instead of to resistor 1. Then the motor speed is controlled, so as to maintain a constant speed level, by the predetermined constant trigger phase command signal generator circuit including transistor 174 and resistor 176.
The predetermined braking threshold level is determined by adjustment of variable resistor 146 in the deceleration detector circuit. The predetermined braking threshold level is selected to be above the constant speed level which corresponds to the resistance of resistor 176 of the predetermined constant trigger phase command signal generator. Therefore, the output voltage of analog IC 147 falls to zero before motor speed falls to the constant speed level, and transistor 151 of the deceleration detector circuit turns OFF. The thyristor 166 of the brake command circuit remains ON through the fourth mode selector switch L and reed switch 153 and 152. Motor speed falls to the constant speed level (intervals x and y in FIGS. 10 and 12). Then the reed switch 153 is opened when sewing needle is at the lowered halt position, by which the thyristor 166 turns OFF and the voltage level at connection point (k) rises to voltage V. Therefore transistor 174 turns OFF and Zener diode 132 breaks down to trigger thyristor 135 and transistor 136. The voltage levels at connection point (a) and c1 fall to zero when transistor 174 turns OFF and thyristor 135 turns ON. Thus the output voltage level of analog IC 33a rises to level V, so as to charge capacitor 43 through resistor 39 and diode 41. However, the anode of diode 41 is connected to zero level line 18 through diode 178 and transistor 136. This prevents the charging of capacitor 43 (voltage clamp at connection point e). Therefore, electric current flows into field winding 6 of motor unit B, and thyristor 135 conducts to provide a dynamic brake force. Thus the motor stops quickly and accurately at the position which corresponds to the lowered halt position of the sewing needle.
Thereafter, transistor 120 turns OFF after the charging time constant of resistor 126 and diode 128, by which thyristor 135 and transistor 136 are deenergized to turn OFF at the electric phase angle N shown in FIG. 7, (a). The voltage level at connection point (e) rises as capacitor 43 is charged through diode 41. On the other hand, turning transistor 136 OFF causes capacitor 181 to charge, which in turn causes transistor 182 to turn ON during the time constant of capacitor 181 and resistor 180. Turning transistor 182 ON causes capacitor 71 to discharge, which turns transistor 69 ON. Therefore the positive voltage V of line 19 is supplied to the minus terminal of analog IC 53. Transistor 60 turns OFF. In short, the trigger signal for thyristors 21 and 22 is terminated and the motor comes to a standstill when transistor 120 is turned OFF.
The above description of stop control operation is similarly applicable to the raised halt position stop control for the thread take-up lever or the sewing needle, by setting the four mode selector switches M, N, K and L at the second position (contacts M-2, N-2, K-2 and L-2 are selected). In this case, position detection by reed switch 154 triggers shunt thyristor 135, and the motor stops at a predetermined position which corresponds to the raised halt position of the thread take-up lever or the sewing needle.
Sixth, we assume that the first, second, third and fourth mode selector switches M, N, K and L are changed-over to the first or second position when the sewing machine is at a standstill. The pulse generator circuit which includes resistor 109, capacitor 110, and diodes 111 and 112 generates a pulse a predetermined width and supplies it at resistor 113 when the selector switches are changed-over into the first position. Similarly, a pulse is supplied by the pulse generator circuit which includes resistor 105, capacitor 106, and diodes 107 and 108 when the selector switches are changed-over into the second position. After generation of the pulse, operation of the sewing needle stop control, as described previously during discussion of the fifth assumption, is obtained, and the sewing needle stops at the lowered halt position or the thread take-up lever stops at the raised halt position. This occurs without operation of the foot controller.
Seventh, we assume that the selector switches M, N, K and L are set at the third position, i.e., "one stitch sewing". Voltage of level V is supplied to the emitter of transistor 120 through contact K-3 of the third mode selector switch K and diode 119 of the start detection circuit. Forcing the foot controller down turns transistor 114 of the start detection circuit to turn ON. Thus a pulse of a predetermined width is generated at diode 117. The pulse turns transistor 121 ON, then transistor 120 turns ON. Voltage of level V is supplied to thyristor 155 of the first memory circuit through diode 129 and resistor 156. At this time the first reed switch 153 has been closed, because the thread take-up lever has been at the raised halt position. Therefore, thyristor 155 of the first memory circuit is triggered ON by the pulse from diode 117. Then transistor 171 of the one stitch sewing speed indication signal generator circuit turns ON to drive motor unit B at a predetermined speed which corresponds to the phase control voltage obtained from the combination of resistor 173 and variable resistor 177. Thyristor 155 and transistor 171 turn OFF when the sewing needle comes to the lowered halt position. At this time, the voltage at connection point (j) rises to level V and a pulse appears at resistor 113 through diode 165 from the change over pulse generator circuit including capacitor 162, diode 164 and resistor 163. The capacitor 128 discharges again in correspondance with the pulse from diode 165. At this time the second reed switch 154 has been closed. Then thyristor 166 of the second memory circuit and transistor 174 of the predetermined constant trigger phase command signal generator circuit turn ON. Therefore, motor unit B is energized by a phase control voltage from the combination of resistor 176 and variable resistor 177 during the movement of the sewing needle from the lowered halt position to the raised halt position.
The second reed switch 154 is opened when the thread takeup-lever (or sewing needle) comes to the raised halt position. Then thyristor 166 of the second memory circuit turns OFF at the time when transistor 151 turns OFF. Transistor 174 of the predetermined constant trigger phase command signal generator circuit turns OFF. Thus the motor stops and thyristors 21 and 22 are turned OFF, as described hereinbefore in the fifth assumption. Operation as described in this seventh assumption is based on the assumption that the foot controller has been released and slider 2 touches contact 3a before the sewing needle comes to the lowered halt position. If the foot controller is released after the sewing needle comes to the lowered halt position, the start of dynamic braking by thyristor 135 will be slightly delayed because transistor 121 turns ON again by the pulse from the pulse generator circuit which includes resistor 101, capacitor 102 and diode 103. If the foot controller is released after the thread take-up lever stops in the raised halt position and transistor 120 turns OFF, capacitor 128 will discharge in correspondance with the pulse from the pulse generator circuit. Therefore transistor 120 turns ON in a predetermined time interval and gate current will be supplied to thyristor 135 because thyristor 166 remains OFF. However, as described above, the sum voltage level Ve+d corresponding to connection points (e) and (d) exceeds the voltage Vf at connection point (f), so that thyristors 21 and 22 are not triggered. The motor remains at a standstill. Consequently, one stitch sewing is obtained completely whenever the foot controller is forced down or released.
Eighth, we assume that the sewing needle is jammed and the sewing machine stops before the needle comes to one of the predetermined halt positions. Release of the foot controller (slider 2 returns to contact 3a) energizes the pulse generator circuit including resistor 101, capacitor 102 and diode 103. A pulse appears at resistor 113 and transistor 120, thyristor 166 and transistor 174 turn ON. Therefore motor speed falls to the constant speed level which corresponds to the resistance of resistor 176. The voltage at connection point c1 falls to the zero level because the sewing needle is jammed and the motor stops. Thus the output of analog IC 33a falls to the zero level and capacitor 43 discharges through resistor 40 and diode 42. The voltage level at connection point (e) falls, by which the trigger phase of thyristors 21 and 22 leads so as to increase the power to motor unit B. The motor may be overheated and destroyed by excess current through thyristors 21 and 22 if the motor remains in the stopped state. However, the timer circuit, which includes transistors 120 and 121, thyristor 127, capacitor 128 and resistors 124, 125 and 126, interrupts power to motor unit B before overheating occurs. Transistor 120 turns OFF a predetermined time interval after the release of the foot controller, because the voltage across capacitor 128 rises when transistor 120 conducts and then turns transistor 120 OFF. At the same time thyristor 166 and transistor 174 turn OFF. The voltage level at connection point (a) falls to zero and the output voltage of analog IC 33a rises to level V, which causes the voltage at connection point (e) to rise so as to retard triggering of thyristors 21 and 22, and finally the trigger pulse to thyristors 21 and 22 disappears. Thus motor unit B is deenergized.
When thread is wound on a bobbin, the thread winding mechanism is operated and reed switch 152 is opened. Therefore reed switches 153 and 154 have no relation to the dynamic brake control of the motor. After the foot controller is released and slider 2 touches contact 3a, the shunt thyristor 135 is triggered when transistor 151 of the deceleration detector circuit turns OFF.
When the operator rotates the driving pulley with his hand after the sewing machine stops, armature 5 in motor unit B and reed switches 153 and 154 will be operated. However, the control circuit will not operate. Thus the driving pulley can be manually operated after the sewing machine stops. The operator can shift the sewing needle at any height.
The embodiment shown in FIG. 1 and described hereinbefore comprises, in addition to a one stitch sewing control circuit system, a dynamic braking system to stop the motor at a predetermined halt position and an automatic protection circuit system to prevent overheating of the motor when the sewing needle is jammed and stops before it arrives at a predetermined halt position.
The operation of the embodiment in relation to the one stitch sewing is summarized as follows. When the first, second, third and fourth mode selector switches M, N, K and L are set at the third position, i.e., one stitch sewing, and the foot controller is forced down by an operator, a pulse is generated by the start detection circuit including transistor 114, resistor 115 and capacitor 116. Thyristor 155 of the first memory circuit is triggered to turn ON by the pulse, by which transistor 171 of the one stitch sewing speed indication signal generator circuit turns ON. The one stitch sewing speed indication signal is supplied to analog IC 33a, which is a comparator circuit, and motor drive thyristors 21 and 22 are triggered to turn ON at a predetermined phase angle so as to energize motor unit B as discussed above. Thus the motor begins to rotate. When the first reed switch 153 is opened by the magnet, which rotates in synchronism with the sewing needle, the thyristor 155 turns OFF. This turns transistor 171 of the one stitch sewing speed indication signal generator circuit OFF, and then thyristor 166 of the second memory circuit turns ON. Thus transistor 174 of the predetermined constant phase command signal generator circuit is biased to turn ON. Then the constant trigger phase command signal generator circuit, including transistor 174 and resistor 176, supplies the constant trigger phase command signal to the analog IC 33a. Then motor unit B is energized to rotate at a lower speed. Thus motor speed decreases. Thereafter, the second reed switch 154 is opened by a magnet which rotates in synchronism with the sewing needle. Transistor 174 is then biased to turn OFF, and shunt thyristor 135 is triggered to turn ON. The motor then stops by the deenergization of the transistor 174 and the dynamic braking by the thyristor 135.
The first reed switch 153 has been described as being open at the lowered halt position of the sewing needle, but it may be opened before or after the lowered halt position of the sewing needle. This means that the change-over of the motor speed in one stitch sewing may be determined in accordance with the starting characteristics of the motor and/or the sewing machine as well as the dynamic braking characteristics. It is not necessary to keep motor speed at the first or second constant level within the one stitch sewing. The one stitch sewing indication signal and the predetermined constant phase, trigger command signal may simply indicate target speeds for accelerating and decelerating the motor within the one stitch sewing.
As described above, the motor is energized to accelerate quickly at start time and thereafter decelerated to stop at a predetermined halt position smoothly and correctly. Thus acceleration and deceleration are controlled within a one stitch sewing cycle.
The foregoing disclosure represents the preferred forms of the invention. It should be understood that various modifications and alternatives may be adopted and utilized by those skilled in the art without departing from the spirit and scope of the invention, which is to be construed in accordance with the claims appended hereto.
|
A motor control system for one stitch sewing control of a sewing machine is disclosed. Motor speed is controlled by controlling the trigger phase of motor drive thyristors. Two needle position detectors are employed to detect the arrival of the sewing needle at predetermined halt positions. A pair of motor speed indication signal generator circuits, a pair of memory circuits and a start pulse generator circuit are employed. When the one stitch sewing mode is selected and the foot controller is forced down, the first memory circuit memorizes the start of one stitch sewing and energizes the first motor speed indication signal generator circuit so as to drive the motor of the sewing machine at a predetermined sewing speed. When the first needle position detector detects the arrival of the sewing needle at the lowered halt position, it deenergizes the first memory circuit and the first motor speed indication signal generator circuit, and energizes the second memory circuit for energizing the second motor speed indication signal generator circuit so as to drive the motor at a predetermined lower sewing speed. When the second needle position detector detects the arrival of the sewing needle at the raised halt position, it deenergizes the second memory circuit and the second motor speed indication signal generator circuit. Deenergization of the second memory circuit causes a brake command signal which activates a brake means.
| 3
|
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is related to and comprises a continuation in part of the United States patent application of the same inventor, Ser. No. 10/008,545, filed on Nov. 13, 2001, which is a continuation in part of the U.S. patent application Ser. No. 09/559,682, filed on Apr. 27, 2000; said previous application being related to its provisional application having Serial No. 60/131,697, filed on Apr. 30, 1999, all of said applications being owned by the same inventor.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
BACKGROUND OF THE INVENTION
[0003] This invention relates primarily to the treatment of lymphedema, and the use of various instrumentation that can effectively lessen the painful and deleterious aspects of such disease as manifested in the body.
[0004] As is well known in the art, lymphedema is a collection of fluids within the tissue, usually extremities, such as one or both of the arms, one or both of the legs, and which is caused from various etiological causes. Lymphedema can be a primary illness that is congenital. This can either result from aplasia of the lymphatic system, which may occur as a result of a complete lack of development of the same, or can be caused by hypoplasia of the lymphatics, such as an underdevelopment of the lymphatic system. Furthermore, lymphedema can be caused, and result from inflammatory diseases. These include mostly bacteriological infections. The non-infectious inflammatory causes are due to a variety of impairments, such as malignancies where the lymphatics can be blocked by tumor cells, or the lymph nodes can be blocked by tumor cells. In addition, it can result from the surgical removal of various lymph nodes, and the surgical interruption of the normal performance of the lymphatics. Furthermore, such can come from radiation that causes sclerosis or scarring of the lymphatics. Furthermore, such can result from chronic venous diseases of long standing origin. In addition, lymphedema can come from severe local injury to a limb. Furthermore, it is usually the infectious element that accompanies such an injury that may result in the onset of lymphedema. Lymphedema can also originate from the blockage of lymphatics by various parasites. Finally, pathology in lymphatics can come from various systemic diseases including myxedema, renal disease, such as nephritis or nephrosis, with loss of protein materials, and can derive from various collagen diseases and fibrotic diseases. All of these diseases result in obstruction of the lymphatic flow and thus causes an accumulation of fluids in the effected limb or limbs. It is also known that cardiac failure can also cause the onset of this malady.
[0005] Until recent years, the lymphatic system's anatomy has only been demonstrated in its larger or more gross form. Millions of small lymphatic ducts have not been truly understood or demonstrated until the past several years, and only as a result of extensive research. The smaller lymphatics, which were cannulated under the magnification of the electron microscope, have been demonstrated as playing a role in the onset of this type of disease. Such had been predicted for a number of years, but it was not demonstrated until approximately two years ago. Now, the network of the lymphatic system is fairly well understood and known. The lymph system is actually inherent in all of the bodily organs, but the major part of the lymphatic system in the extremities is in the subcutaneous tissues. Such has been demonstrated.
[0006] The effects of lymphedema on the patient are well known. Patients generally are somewhat or significantly disabled according to the limb that is affected. Usually, with the onset of lymphedema, the patient either has one or two lower limbs that are very heavily affected, and manifest a heavy accumulation of such body fluids. As the disease progresses, it hampers the patient's ambulation and makes it very difficult for normal clothing to fit. Eventually, normal everyday activities become limited. If lymphedema effects the upper extremity, the hand is markedly affected, and the mobility of the hand, fingers and thumb, etc., are eventually also affected. In addition, these people, subject to lymphedema, are very susceptible to various other serious infections. A very slight portal of entry, such as a cut, pin stick, hangnail, or the like, or anything that allows the entrance of bacteria into the lymphatic system becomes a very serious cellulitic process. This can reach proportions of fever and chills, and even require hospitalization, and if uncontrolled can even cause septic shock and death. The reason for this is that the lymph fluid is a perfect media for bacteria to grow in and there is an abundance of such fluid in those subcutaneous tissues.
[0007] Lymphedema is commonly seen in either the upper or lower extremities of the body as mentioned above. This can be either individually, or isolated in its location, depending upon where the lymph nodes have been removed, or it can manifest itself in a variety of these extremities, after its onset. Some of the cases of lymphedema are normally due to chronic venous disease. However, the largest number of such cases have been caused by secondary reactions to radiation and radical surgery where either all of the lymph nodes were removed from a groin area, the pelvis, or from an axilla. There was no real algorithm of treatment until the late 1980's.
[0008] Currently, literature has become more proliferative on the problems associated with lymphedema. Studies, even by the inventor herein, have focused more attention to lymphedema, and have led to an extrapolation of some hypothesis as to its etiology at the level of the microscopic lymphatics.
[0009] There are a variety of treatments that are currently available for lymphedema, and most of them, relate to some type of wrapping or compression of the effected area, in an effort to reduce the accumulation of the fluids. Many of the processes have included various types of wraps, or pumps, for achieving a dissemination of the localized fluids.
[0010] For example, the Reid sleeve is one such instrument that has been used for the treatment of lymphedema. It is a sleeve type compression device, almost in the nature of a cast, but in this instance, formed of more flexible type of nylon or related materials. Then, a series of straps can be tightened around the sleeve, at the situs of the accumulated fluids, and tightened by means of any type of fastener associated with such straps, in order to apply compression at the site of treatment. Thus, the essence of the Reid sleeve is simply to provide a massive amount of physical pressure by tightening of a sleeve about the infected area.
[0011] The use of such compression bandaging has provided some beneficial results to the patient, and has achieved limb reduction, enhanced skin tone, and softer skin texture, but, the use of such a bandage does have the potentially harmful effects of functioning like a tourniquet upon the effected area, and unless the amount of pressure applied is significantly controlled, can have further detrimental effects in the nature of reducing blood circulation and flowage, which can be very harmful to the patient, if not properly supervised. Most of these sleeve type of devices, available in the art, may be initially applied by the medical practitioner, in the office, but once the patient takes it home, he/she will either be advised or have a tendency to apply such sleeves themselves, which can afford no regulation over the amount of pressure applied by such a compression sleeve, once installed.
[0012] It has also been suggested, recently, that some type of air compressive means or strap may extend, at a slight width, along the internal length of the Reid or related sleeves, and be pumped up to provide additional tightness to the device encompassing the limb. But, once again, such applications offer little or no control over the amount of pressure applied, or the benefits or harm that may result from their usage, particularly when applied by the patient alone.
[0013] Various United States patents have previously issued relating to technology available for treatment of accumulation of body fluids, or for other treatments. For example, in the U.S. Pat. No. 4,029,087, entitled “Extremity Compression Device,” there is shown, as can be seen in its FIG. 1, a wrap that applies compressive pressures against the patient's limb, forming interconnecting annuluses, as noted, and which are inflated. Generally, this particular compression device is for application to patients that are bedridden, for some time, and with the added pressure it is believed that assistance to blood flow may be enhanced, to reduce swellings associated with edema in the extremities.
[0014] The compressive sleeve to Hasty, shown in U.S. Pat. No. 4,091,804, shows a form of sleeve that is applied to the patient's limb, and subjects the same to compressive pressure, as a result of the injecting of compressive air into the various chambers, as noted, to provide compressive pressures against the patient's limb.
[0015] The patent to Annis, U.S. Pat. No. 4,207,876, shows a compression device with ventilated sleeve. This device may be applied, as for example, to the leg of a patient, to apply compressive pressures, during treatment. This device includes various openings to provide ventilation to the limb, during the application of this compression device, when used for treatment.
[0016] The patent to Kapp, et al, U.S. Pat. No. 4,256,094, shows an arterial pressure control system. This device utilizes a fluid pump for inflating a cuff, which functions, apparently, to provide arterial pressure, not too unlike that of the manual tourniquet.
[0017] The patent to Dillon, U.S. Pat. No. 4,269,175, discloses an apparatus that promotes the circulation of blood. This particular device, when applied, as for example, to the leg, and fluid pressure is injected into the same, as can be seen in its FIG. 1, is designed to enhance or provide intermittent external pressure pulses to the leg, to enhance blood flow, to and from the heart.
[0018] The patent to Villanueva, U.S. Pat. No. 4,374,518, shows an electronic device for pneumomassage to reduce lymphedema. This device includes the fabrication of an outer boot, that may fit, for example, to conform to the human foot and leg, and utilizes a compressor to provide for successive inflating and deflating of the boot, within a preselected cycle, in order to stimulate fluid flow.
[0019] The patent to Arkans, U.S. Pat. No. 4,396,010, shows a sequential compression device. This device, as with those as previously described, is a pressure generating device for applying compressive pressures from a compressor against the patient's limb, through the use of a flexible, prepressurizable sleeve that encloses the limb and apparently pulsates pressure to the sleeve, and on to the limb, to enhance fluid flow.
[0020] The patent to Mummert, U.S. Pat. No. 4,408,599, discloses another complex apparatus for pneumatically controlling a dynamic pressure wave device. This device includes a series of longitudinal chambers that are subject to pressure inflation or deflation, by a dynamic pressure generating device, which is highly controlled by means of electrically operated components.
[0021] The patent to Siemssen, et al, U.S. Pat. No. 5,179,941, shows a contractile sleeve element and compression sleeve made therefrom for the peristaltic treatment of extremities.
[0022] The patent to Cariapa, et al, U.S. Pat. No. 5,437,610 shows another complex device incorporating various compression units, and pump means, which functions as an extremity pump apparatus.
[0023] The patent to Tumey, et al, U.S. Pat. No. 5,443,440, shows another form of medical pumping apparatus, in this particular instance, for application to the foot, and which can be inflated, in order to apply pressure to the foot, during its treatment for various impairment.
[0024] The patent to Peeler, et al, U.S. Pat. No. 5,575,762, shows a gradient sequential compression system and method for reducing the occurrence of deep vane thrombosis. This is a complex apparatus, for treatment as a therapeutic medical device and method for improving the venous blood flow within the patient.
[0025] The patent to Cone, et al, U.S. Pat. No. 5,591,200, shows another method and apparatus for applying pressure to a body limb for treatment of edema. This device is similar to the Reid sleeve, as previously reviewed.
[0026] Finally, the patent to Tobler, et al, U.S. Pat. No. 5,626,556, discloses a hook and loop attachment on a compression sleeve. This particular device also is related to the Reid sleeve type of apparatus, as previously explained, and does provide for the application of air pressure, into the lateral annuluses, as shown; to provide an inflated pressure against the foot, as can be noted, for the treatment of the patient's leg, and perhaps other extremities.
SUMMARY OF THE INVENTION
[0027] This invention relates generally to a portable form of compressive garment that may be selectively applied to various extremities of the body to provide for treatment of lymphedema and related forms of edema.
[0028] The lymphatic system of the body is actually a part of the human closed hydraulic system of circulation within the anatomy, that provides for sustaining normal physical function of the body parts, provides the proper displacement and movement of the various fluids, separate and apart from the circulation of blood within the body. As can be seen in FIG. 1, the location and functionality of the heart, lungs, the arteries, veins, and the other circulatory and vascular system of the body is compatibly associated with the extracellular lymphatic space. These lymphatic channels provide for transportation of lymph fluids to lymph nodes that remove various materials such bacteria and debris. Finally, the lymph fluid is discharged into the veins by way of the thoracic duct. Thus, this portion of the vascular system combats disease, by carrying away the deleterious bacteria and other infections elements that can cause problems to the body. In this FIG. 1, blood flowing into the small vessels (arterioles) entering the capillaries at that level, delivers nutrition to the intracellar spaces by ultrafiltration. After depositing nutrients to the cells, the fluid traverses the extracellular space and is resorped in the venous end of the capillaries. However, only 90% enters the venous plexus and 10% flows into the lymphatics. The latter is profused through the lymph node basins (inguinal, axillary, intra abdominal and supraclavicular) and returned to the large veins at the left thoracic inlet via the thoracic duct. Thus, the fluid exchange that contributes to lymph formation originates at the microscopic level and is governed by Starlings laws of capillary function.
[0029] The subject matter of this current invention contemplates the formation of a compression garment that is selectively designed and manufactured to provide for application by the patient himself/herself. Once instructed, in proper placement it furnishes greater and more precise control, for treatment of the deleterious side effects manifested by and through lymphedema, as explained. In essence, the subject matter of this invention provides for the formation of an external compression device that may be applied to the arm, and embrace even part of the hand, or even extend upwardly into the region of the shoulder. Or, the sleeve may be especially designed for application to the leg, and extend down into the region of the ankle, and even embrace part of the foot, and extend upwardly towards the knee and thigh, depending upon the severity of the lymphedema being treated, and its location. Thirdly, the invention contemplates the formation of a further wrap, fabricated to the same principle as that of the previously identified sleeves, and which may embrace the upper thighs, and the lower abdomen, in order to provide the precise application of select pressure to the accumulation of body fluids, caused by lymphedema, manifested at these regions of the body. Adaptation for the thorax is also a possible option.
[0030] In essence, the appliance of this invention is formed as a flexible cloth, polymer, or related type of material, that has a series of grommets or seal points that form individual and smaller pressure chamber segments internally of the overall formed device. As grommets, placed 3 cm apart, provide for venting, from between the skin surface and the device, once installed.
[0031] In addition, there are one or more inflation or deflation valves, operatively associated with the internally formed compartments for the device, and in addition, the selective emplacement of the grommets, during formation of the device, furnish subsidiary chambers throughout the length of the formed device, so that multiple pressure points may be generated, within the inflated device, to apply multiple sites of pressure to the lymphedema that is subject to treatment. This strategic placement affects capillary pressures. The device is custom made, so that it may precisely fit not only upon the arm, leg, or the like, but has appendages that allow for the selective application of the device, for example, around the hand, under the thumb, so as to provide adequate coverage to all aspects of the limb subject to treatment, and afford a uniform application of pressure, through its various and multiple pressure points, to provide for a displacement of the edematous fluids, and their movement back into the circulatory system, in association with the adjacent lymphatic nodes, lymph vessels, and shifting of such fluids throughout the lymphatic channels, to reduce the undesired and frequently painful fluid accumulations.
[0032] In the formation of the device, at least a pair of layers of sturdy but flexible material, such as nylon, or other material that can be fabricated to provide for its inflatability, remain hermetically sealed, and be subject to significant pressures, while sustaining inflation, in order to function as an instrument for treatment of lymphedema, as previously explained. The precise location of the grommets, used to contiguously adhere the layers, at particular sites, but to allow for its inflatability, so as to form essentially three-dimensional diamond shaped pressure points. This allows increased venous flow by decreasing arteriolar hydrostatic pressure at these pressure points. These grommets, approximately three centimeters apart, more or less, afford a multiplicity of pressure points, upon the surface of the skin, thus reducing the lymphedema fluid, during usage. Obviously, other dimensions for placement of the seal points, or grommets, may be considered, depending upon the degree of lymphedema being treated, and it is likely that the grommets may be located approximately one inch apart, or as much as five inches apart, depending upon the degree of pressure required, to sustain a uniform pressure over the entire surface being treated.
[0033] In addition, there are various inflation or deflation valves that may be added to the device, to allow for its inflation, and there may be a single valve, or perhaps valves that may locate approximately two to four inches apart, to allow for isolated injection of air into the device, during its inflation, once placed on the limb. The patient himself/herself may actually apply the device, by wrapping it, as an example, about the arm, and the hand, and secure the same in the position by means of any type of straps, such as Velcro hook and pile type tab connections, that may extend along the marginal edge of the device, and cooperate with a velour surface applied externally to the device, to furnish securement. Or, a series of Velcro or other buckle straps may locate along the margins of the device, and allow for a strap fastener of the wrap, about the arm, leg, or the like, once installed.
[0034] Any type of a pressure applying and generating device may be used, for inflating the device, such as a bulb type hand pumping and fitting means, of the type that is available from Haikey-Roberts Company, of St. Petersburg, Fla., and which is shown in its U.S. Pat. Nos. 4,744,391 and No. 4,998,582. These hand pumps, that incorporate their own fittings, may be pumped for injecting pressurized air into an encapsulated space, in order to inflate the same, or its opposite end incorporates a fitting that may be inserted into the inflation-deflation valves, to allow for a deflating of the device, after its usage. Other bellows type air inflating device may be used. Normally, the amount of pressure that is applied in the device of this type, and which has been found effective, is in the range of 35-45 mmHg, more or less. Thus, the amount of pressure applied is not too great, when it is compared with the amount of pressure that exists in the normal vascular system of the body, where a blood pressure may extend between diastolic and systolic ranges between 70-80 mmHg and 110-120 mmHg. On the other hand, the amount of pressure applied into this device, by means of a pressurized air injecting means, such as the bulb as previously explained, may be between the ranges of 5-10 mmHg, and upwards of 20-25 mmHg, or even as high as 40-50 mmHg, depending upon the amount of treatment required, and the form and extent of edema that may be present due to the magnitude of the lymphedema that exists.
[0035] Various other types of valves may be included in the structure of this garment, within each segment of its formed multi-compartment wrap, so that each segment may be individually filled with air, under pressure, to the amounts as previously reviewed, necessary to treat the degree of lymphedema that has been generated within the limb at that contiguous location. For example, various types of shut-off valves, one-way check valves, and valves that may be manually opened, to provide for release of pressurized air, are readily available from a variety of sources. For example, Colder Products Company, of St. Paul, Minn. 55114, manufactures and markets a variety of various types of valves, check valves, release valves, and couplings, for use for the application and release of air, under pressure, to medical instruments. In addition, the Martin-Weston Company, of Largo, Fla. 33770, manufactures and markets inflation pumps that may be applied to the foregoing type valves, to allow for the injection of air under pressure into the segments of this garment, during its installation and usage. On the other hand, instead of utilizing a manual type of pump, there are many more expensive type of pumps, valves, seals, and the like, that are available from a variety of sources, such as the fill and drain closures that are available from a company such as Halkey-Roberts Corporation, of St. Petersburg, Fla. Furthermore, in order to determine the degree and amount of pressure applied into each segment of this garment, hand-held type of digital manometers may be used, and applied to the valves after or during the injection of air, to provide for an immediate digital readout of the amount of pressurized air that has been applied into each segment of the garment, so that more precise levels of pressure can be generated, at select locations along the length of the garment, as applied to a limb. Such hand-held manometers are available from Dwyer Instruments, Inc., of Michigan City, Ind. 46361, amongst other and a variety of sources.
[0036] In addition, in lieu of the use of a manometer, attached to the valves or to the segments of this wrap, it is just as likely that a form of pressure transducer may be utilized within each segment of the wrap, detect the amount of pressure generated therein, convert it to a charge, and transfer it to a readout, upon the surface of the segment, where the generated pressure may be readily observed. Such transducers may be obtained from Linton Instrumentation, of Diss, Norfolk, U.K., under Model No. SensoNor 840. For example, an LED readout that may display the quantity of pressure generated could be provided upon the surface of each segment, to let the physician and medical technician know the exact amount of pressure generated within each segment, during usage and application of the wrap. Also, if the patient utilizes the garment at home, through self service, this would provide a ready readout as to the amount of pressure pumped into each segment, during usage and application, so the patient may be quite precise in the amount of pressure developed within the wrap, in accordance with the specifications from the doctor, instructing regarding its usage. Furthermore, the pressure transducers may be incorporated into the inner surface of the wrap, or applied upon that surface of the wrap that is applied directly to the affected limb, so that an exact reading of the amount of pressure generated upon the surface of the limb subject to lymphedema, may be readily determined, upon usage of this particular garment.
[0037] Obviously, the type of material used as previously referred to in forming the multi-layer device, that exhibits the internal chambers that are fabricated to provide for the multipressure points from the device, when used, and may include those materials as previously described, while the internal surfaces of the liner may be treated, to make it hermetically sealable, or it may include an internal liner of a polymer, such as polyethylene, to assure that the device, during usage, will be pneumatically leak proof.
[0038] In addition, and in the case of the device as manufactured for use upon the arm, it may extend and wrap around the palm, leave clearance for the fingers and thumb. It may provide integral wrapping about the wrist, forearm, elbow, biceps, and even extend up into the region of the shoulder. Or, the device can be formed of a shorter dimension, depending upon the localized need for treatment. In addition, it may be formed for wrapping about the leg, the thigh, down to the ankle, and even about a portion or all of the foot, depending upon the severity of the lymphedema, and the type of treatment required. And, as previously explained, the device may be fabricated for wrapping about the lower abdomen, and have a connecting portion that may wrap about, individually, each of the upper associated thighs, to provide a localized treatment at that region of the body, which can frequently manifest lymphedema that requires treatment as such swelling may result from radical surgery that is done for cancers in the pelvic organs, such as the uterus, ovaries, rectum and prostate. Radiation of this region can also cause sclerosis of lymphatics resulting in edema.
[0039] It is, therefore, an object of this invention to provide an appliance for use for treatment of lymphedema that is light weight, very portable, washable, and easily applied, even by the patient alone.
[0040] Another object of this invention is to provide a lymphedema treating device that includes a series of perforations, at the region of grommets, or seals, which provides two beneficial results. One, which allows the access of air to the underlying and wrapped skin during usage of the device, but secondly, includes a series of seals, at these locations, which afford the generation of air pockets. This series of grommets produce a multitude of pressure points internally along the entire length and circumference of the applied sleeve rendering variable pressure on the capillary beds.
[0041] A further object of this invention is to provide a pressure garment that allows for its generated pressures, internally, during usage, to be precisely controlled, even by the patient during application and usage. LED pressure sensors provide this information.
[0042] Still another object of this invention is to provide a much less costly type of appliance, for treating lymphedema, than currently in use.
[0043] Still another object of this invention is to provide a pressure garment that incorporates at least two fail-safe features, one is in a valve or valves that allows filling only a certain pressure, and/or an appliance that fills the air chambers that only allows a maximum pressure of up to 45 mm of mercury, or slightly there above, and certainly below such level as could be harmful.
[0044] Still another object of this invention is to provide for a pressure garment for use for treating lymphedema that is easily and quickly applied to the effected limb.
[0045] Yet another object of this invention is to provide a pressure garment that is durable.
[0046] Still another object of this invention is to provide a device for treating lymphedema which is very compact, as during nonusage, and is very accommodatable for travel, when required.
[0047] Another object of this invention is to provide a very simple design that is safe in its application, installation, and usage.
[0048] Yet another object of this invention is to provide a pressure garment which when applied can aid towards decreasing post-operative edema and thus decrease post-operative disability and enhance the healing of a wound.
[0049] Another object of this invention is to provide a lymphedema treating device that may facilitate and be of help to the patient after orthopedic surgery, any surgery, or even during post-operative vascular surgery healing in the extremities.
[0050] Yet another object of this invention is to provide a somewhat flexible, inflatable edema treating device that will further act as a support that may even function somewhat as a cast to limit the amount of flexion of a limb, but yet, have sufficient flexibility to allow the limb to attain some movement, during usage.
[0051] Another object of this invention is to provide a garment for use for treating lymphedema that may be manifested, usually after surgery, in various limbs of the body, such as along the arms, in the lower reaches of the legs, at the thighs, or even in the vicinity of the abdomen, and unless treated, results in a buildup of significant accumulation of bodily fluids that are unsightly of appearance, but more specifically, detrimental to the continuing health or recovery rate of the patient. A body wrap may be beneficial in burn treatment also.
[0052] These and other objects may become more apparent to those skilled in the art upon reviewing the summary of this invention, and upon undertaking a study of the description of its preferred embodiment, in view of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] In referring to the drawings, FIG. 1 provides a schematic view of the human closed hydraulic system of circulation of both vascular and lymphatic fluids depicting the formation of lymphatic fluid in the extracellular space.
[0054] [0054]FIG. 2 provides a perspective view, both in the lateral view, and the medial view, of the compression garment of this invention applied about the lower arm and hand of the patient;
[0055] [0055]FIG. 3 is a plan view of the compression garment, during nonusage, as shown in FIG. 2;
[0056] [0056]FIG. 4 is a sectional view of the arm applied garment, taken along the line 4 - 4 of FIG. 2;
[0057] [0057]FIG. 5 is a view of a modified form of garment, that extends up to and onto the shoulder of the patient, from the vicinity of the wrist, for applying selective and controlled pressure along the length of the arm, to treat edema;
[0058] [0058]FIG. 6 is a view of the application of a modified garment to the thigh, leg, and ankle of the patient;
[0059] [0059]FIG. 7 is a view of a modified garment of the type that is applied at the vicinity of abdomen and upper thigh of the patient to provide edema treating pressure at these vicinities of the body;
[0060] [0060]FIG. 8 is a plan view, or open view, of the modified garment shown in FIG. 7;
[0061] [0061]FIG. 9 is a schematic view of the front face of the electronic controller that is used for regulating the quantity of pressure added to or removed from various segments of the sleeve, during its usage;
[0062] [0062]FIG. 10 provides a sectional view of the hand section of the sleeve, showing the various raised air pockets, the circuit lines leading to select of the air sections of the sleeve, which provide for a sensing as to where pressurized air must be added, or subtracted, in order to equalize the pressure of the sleeve upon the limb being treated;
[0063] [0063]FIG. 11 provides a sleeve pneumatic schematic;
[0064] [0064]FIG. 12 provides a further modification to the sleeve pneumatic schematic;
[0065] [0065]FIG. 13 provides a modification to the sleeve pneumatic schematic;
[0066] [0066]FIG. 14 provides a schematic of the electrical circuitry and the microprocessor controller and monitors for the compression garment of this invention; and
[0067] [0067]FIG. 15 is a further schematic of the circuitry used for the solenoid valves controlling the pneumatics for this compression garment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0068] In referring to the drawings, and in particular FIGS. 2 through 4, the compression garment G of this invention is readily disclosed. In this embodiment, it is applied to the forearm, about the wrist, and embraces part of the hand of the wearer or patient. The garment, as can be noted in FIG. 3, comprises and is formed of a flattened configuration, including upper and lower layers 1 and 2 of a fabric-like material, such as nylon, or any other hermetically sealable type of cloth, polymer, or flexible material, and which can be inflated to sustain pressures of air or other fluids to the amounts as previously summarized. As can be seen, the two layers of material are sealed together, by means of a series of grommets 3 throughout their extent, and which provide for segmented pockets, as at 4 , of air that provide for a generation of point pressures, to the treated arm, as previously explained. The object for forming these various air pockets, along the length of the compression garment, and as previously summarized, is to provide the application of a very controlled pressure, at spaced and isolated locations, to the edema effected limb. At the same time avoiding the application of tourniquet type pressure, throughout the extent of the limb to which the garment is applied, so as to not curtail or shut off the vascular functioning in the effected area. Thus, blood flow in subcutaneous and fluid migration, during he application of the device's controlled pressure, will cause accumulated fluids to continue their circulation, but reduce their accumulation, to attempt to place the affected limb back into its normal processing, normal appearance, and to avoid the deleterious and impairments that may be generated in the limbs, because of the accumulation of the edemic fluids.
[0069] The compression garment may be a continuous length of the material, and liners, forming the length of the garment, and be inflated between its various grommets to form the identified pressurized air pockets, or as shown in FIGS. 2 and 3. The garment may be segmented, between the various segments 5 through 8 , and be individually inflated, by means of their respective valves ( 10 ), as can be noted. These valves ( 10 ) are provided for both inflating of the garment, or its individual segments, or it can be used for discharging and deflation of air, for either greater proper control of the amount of pressure applied, or for removal of the garment, after treatment.
[0070] In addition, the various grommets 3 , as can be seen, have apertures, as at 11 , within their interior, so as to allow for any captured air, between the garment and the surface of the limb skin, to escape, and which would otherwise, or may, provide a variation in the amount of pressure desired, when inflating the garment during usage.
[0071] As can also be seen, various types of sensors, as at 9 , may be installed into the layers forming the surface of the garment, and be sensitive to the amount of pressure being added into the various segments, to provide a ready indication and readout of the amount of pressure applied, so the medical practitioner, or even the patient alone, can readily determine whether adequate and proper pressure levels have been reached, during treatment. Furthermore, various types of microchips, or LED indicators, may be associated with the sensors, and provide a digital, or either analog, readout of the amount of pressure generated within the garment, and its various segments, during usage and application.
[0072] In order to provide for the uniformity for the product, and to add to its appearance, it is likely that a covering sheet, such as one shown by way of example at 10 A, of the same or different material from which the segments of the wrap are formed, may overlap each of the valves 10 and sensors 9 , so as to form means for covering these elements, during usage of the wrap. One edge of the cover may include a hook and pile fastener type of connector, so that the cover may be secured in place, once installed, or pulled free, to expose the valve or sensor, accordingly. See FIG. 3.
[0073] Structural wise, the garment, being previously described as being fabricated of at least a pair of layers, will extend the length of the limb to which it is applied, and as shown in FIG. 2, in that embodiment, extends up to approximately the elbow of the wearer. At its opposite end, the garment may be designed and fabricated, to include sufficient length to override most of the hand, up to the position of the fingers, including a segment at its opposite width, as at 12 , which may embrace the palm of the hand, and cooperate with an appendage, as at 13 , that extends down across the hand, between the index finger and the thumb, and for connection to the portion 13 of the shown garment. Furthermore, the edges of the garment may include, as along the inner surface along one edge, a segment of hook or pile fastener, such as fabricated from Velcro, as can be seen at 14 , while the opposite edge, as at 15 , upon its undersurface, may include the other segment of Velcro, as at 16 , for securement with the defined edge 14 , and allow for the garment, when wrapped, to snugly embrace the limb of the wearer, during treatment. Obviously, other types of fasteners can be utilized, such as clasps, one or more buckles, or any other type of means for securement of the edges of the garment together when wrapped around the limb of the patient.
[0074] In addition, any type of pump means, such as a bellows device, or bulb (not shown), or the like, may be applied to the valves 10 , and facilitate the pumping of pressurized air into the garment, after installation, and in preparing it for treatment. Likewise, any type of release valve, incorporated into the structure of the valves 10 , and which may be manipulated, to allow for discharge of air, will be applied thereto, in order to allow the patient to deflate the garment, and remove it, after treatment. These types of valves are readily known in the art, and are available for this type of adoption, installation, and usage.
[0075] As can be seen in FIG. 5, the garment G 1 is modified, and will extend from the wrist of the patient, up to and over the shoulder, to allow treatment along the extent of the shown limb, as can be understood. In addition, as can be seen in FIG. 6, the Garment G 2 may be further modified, and extend from the thigh, all the way down to the ankle, and even wrap about the foot, and readily available for inflation, to function to treat edema, that may be caused at these locations. Or, the leg wrap may extend simply down the calf, and embrace the ankle, and foot, as an alternative. Furthermore, as can be seen in FIG. 7, the garment G 3 may be applied to the abdomen, waist, and upper thighs of the patient, for treatment of edema thereat. As noted in FIG. 8, this style of garment will have a waist embracing portion 17 , with the usual fasteners 18 , as previously explained, applied to either end, and in addition, will link by means of an appendage 19 to the upper thigh embracing components 20 and 21 , which also include their various fastening means 22 , about the upper leg of the patient. Nevertheless, and regardless what shape or configuration the garment undertakes, in its assembly and manufacture, it will include various upper and lower layers of material, that are hermetically sealed, and which include a series of grommets or other means for fastening of the layers of material together, to form those isolated pillows or segments to form pocketed pressurized air, for treatment of the affected limb, when applied. In addition, and while the terminology grommet has been used herein as means forming these pockets, obviously, these could be simply seal points, that connect the two layers of material together, regardless whether they include the apertures 11 therethrough, as previously explained for preferred embodiment.
[0076] As previously reviewed, the essence of this invention is to provide for a lightweight and washable type of garment, that can be applied to various affected limbs, even by the patient, himself/herself, to attain treatment, as required, or prescribed. It provides for controlled application of pressure, at various points along the treated area, in a manner that does not disrupt the desired and normal biological function of the vascular and lymph systems of the body, particularly at the treated area. In addition, the garment is relatively small, flexible, is very compact for folding, easy to take when traveling, so that treatment can be undertaken anywhere, and not just at the hospital, medical facility, or the doctor's office. It can be done at home, or even on a business trip, as necessary. The garment has sufficient flexion, so that the limb, to which it is applied, can still be used, or manipulated, even during treatment.
[0077] [0077]FIG. 9 discloses the electronic controller, or at least provides a schematic of its front face, showing how various pressures are detected, determined, and used to automatically adjust the amount of air pressure pumped into the various segments of the sleeve, during its operations. Advancements in electronic circuit miniaturization now make it possible to develop a device that can control these pressures, be battery or otherwise operated, they are light weight, add significant safety features and allow for an individual complete freedom to move about and continue in their normal daily routine or sleep in complete comfort. The electronic controller automatically monitors the pressure at each section of the sleeve and verifies that it is set correctly. If, in the case of an arm sleeve, the patient should bend the arm, the sleeve would increase pressure in that section, and the controller would automatically vent that section of the sleeve back to its set point. When the patient straightens the arm, the pressure would reduce and the miniature pump inside the controller would automatically increase the pressure to the original set point.
[0078] As can be noted in FIG. 10, there are circuit leads that have sensors that are responsive to the amount of pressure at the various segments of air pockets, and can determine when pressure is becoming excessive and thereby should be reduced, or when pressure is lightening, and therefore, air should be supplied and pumped to the pocket to add pressure at select locations. This controller has several additional significant uses when used in conjunction with this sleeve devise. One, the pressures can be adjusted periodically on a prescribed time table to dynamically work the skin surface. Secondly, the advance designs of the sleeve could incorporate twin bubble cell circuits in each section so that a constant alternating pressure in each cell circuit would result in a therapeutic massage of the afflicted area resulting in a potentially greater overall fluid reduction.
[0079] [0079]FIG. 11 discloses the lymphedema sleeve and the pneumatic schematic for the compression garment of this invention. As disclosed, the system is composed of a single DC powered air pump, as noted at pump 1 , and includes eight solenoid valves, as noted. Each of the four compression cells, of the preferred garment, is continuously connected by way of tubing to a dedicated pressure transducer, generally identified as PS- 1 through PS- 4 . The pump is connected to a manifold, which feeds each cell via a dedicated solenoid valve, as noted. Each compression cell is provided with a dedicated solenoid valve for venting its particular cell.
[0080] The system is capable of independently pressurizing and venting each compression cell. Variable pressure set points can be independently set for each cell. Fill rates will be impacted by set point pressure and the number of cells that are to be filled. The unit is capable of simultaneously pressurizing a cell(s) while venting another cell(s). Custom pressurization and massage can be implemented. The system will be able to quickly reduce pressure to ease bending the sleeve at the knee/elbow joint.
[0081] This system is capable of simultaneously performing in a desired operation, such as pressurization, static, or venting, on each of its separate compression cells.
[0082] Because of the necessity, in the event that the compression garment is designed incorporating four cells, of including eight solenoid valves within the structure, the cells and the garment will require a little more size, in order to accommodate such componentry.
[0083] On the other hand, the modification for the lymphedema sleeve pneumatic schematic as shown in FIG. 12 reduces the number of solenoid valves used. This system is composed of a single DC powered air pump and five solenoid valves. Each of the four compression cells is continuously connected via tubing to a dedicated pressure transducer. Each compression cell is provided with a dedicated solenoid valve for controlling the pneumatic access to the cell. A common manifold connects each cell control solenoid valve with the common port of a 3-way solenoid valve, as noted at SV- 5 . The normally open port of the 3-way valve is connected to the pump, and the normally closed port is connected to vent, as noted.
[0084] The system is capable of independently pressurizing or venting a specific compression cell. The unit will not be capable of simultaneously pressurizing a cell(s) while venting another cell(s). Variable pressure set points can be independently set for each cell. The fill rate will be impacted by set point pressure and the number of cells that are being filled. Custom pressurization and massage profiles are possible, but they will be limited by the inability to pressurize a cell while simultaneously venting another cell. The system will be able to reduce pressure to ease bending the sleeve at the knee/elbow joint, but the response time will be slower than the schematic as shown in FIG. 11.
[0085] The benefits of this particular system is that it is capable of performing any desired operation, i.e. pressurization, static, or vent, on each compression cell. The limitation of this particular system is that it can simultaneously fill or vent one or multiple cells. But, it can not do so at the same time. As a result, the system may have a desired state delayed until completion of the current cycle or state.
[0086] A further modification to the subject matter of this invention is shown in the system disclosed in the schematic of FIG. 13. This system is composed of a single DC powered air pump and four solenoid valves. Each of the four compression cells is continuously connected via tubing to a dedicated pressure transducer. Each compression cell is provided with a dedicated 3-position solenoid valve for controlling pneumatic access to the cell. The solenoid valve is comprised of two solenoids in three positions. The port position C is the common connection. Port A is a normally closed port that is connected to the common port C when the signal is applied to solenoid A. Port B is a normally closed port that is connected to the common port C when a signal is applied to solenoid B. Port D is the normally open port that is connected to port C when no signal is applied to solenoid A or B. Port C of the valve is capped. Port A is connected to the vent manifold. Port B is connected to the pump manifold. Each cell can be independently connected to the vent manifold, the pump manifold, or closed off.
[0087] This system is capable of independently pressurizing or venting a specific compression cell. Variable pressure set points can be independently set for each cell. Fill rate will be impacted by set point pressure and the number of cells that are being filled. Custom pressurization and massage profiles are possible. The system will be able to reduce pressure to ease bending the sleeve at the knee/elbow joint, and response time will be similar to the design option as set forth in FIG. 11.
[0088] This system is capable of performing any desired operation, such as pressurization, static, or vent, on each compression cell.
[0089] Electrical schematic for operation of the electrical-pneumatic and solenoid controlled valves for the compression garment of this invention is shown in FIG. 14. As noted, power of the system is capable of operation from a rechargeable battery source, or DC power, provided by a standard 120 VAC volt wall adapter. The control includes the battery charge circuitry and battery state monitoring circuitry. The monitoring circuitry includes an alarm output to the microprocessor controller.
[0090] The display, as noted, is a backlit LCD display that provides control setting and operating parameter information to the user. The keypad, as noted, is a sealed multi-switch keypad which provides operator interface with the unit. The alarm, as also noted, is a Pizeo-electric audio alarm that provides audio indication of controller faults. The faults will include the low battery, cell over pressured/under pressured, pump fault and pressure sensor fault
[0091] The pump is a DC powered pneumatic pump that provides pressurized air to the compression cells. The pump is controlled by a digital signal from the microprocessor, or CPU. The manufacturer of the CPU being Motorola, Inc. of Austin, Tex., Model No. 68HC16, or the manufacturer may be Microchip Technologies, Inc. of Chandler, Ariz., model No. PIC8F4320. The microprocessor sends a signal to a FET transistor that provides low side switch control of the pump motor.
[0092] The solenoid valves, generally identified at SV- 1 through SV- 8 , are used to control the pressurization and venting of the compression cells, for the garment. The valves are controlled by a digital signal from the microprocessor to a FET transistor that provides low side switch control of the valve solenoid. Solenoid valves are bio compensated to minimize the effects of switching transients.
[0093] The pressure sensors, as indicated at PS- 1 through PS- 4 , provide a temperature compensated DC signal to the controller microprocessor. The system includes a sensor for each compression cell. The sensors can be mounted on the sleeves or internal to the control unit.
[0094] The various FET transistors, and their association with the various valve solenoids, SV- 1 through SV- 8 , can be seen in FIG. 15. In addition, the operations of the pressure sensors PS- 1 through PS- 4 can also be seen from this figure.
[0095] In the system operation, a microprocessor controller monitors the inputs from the keypad, the battery charger and monitoring circuits and the cell pressure sensors.
[0096] The serial data output from the microprocessor is used to send data to the LCD driver that displays operator information on the LCD. The display is activated in response to an operator input on the keypad, and any alarm condition or system failure. The LCD and keypad are backlit in response to a signal from the “light” button on the keypad. The backlighting remains on for a timed period and automatically turns off when no input from the keypad has been detected for a specified period.
[0097] Depending on pressure set point and the measured pressure from the pressure sensors, the electrically actuated solenoid valves are used to connect a cell to the pressure or vent manifold. Valve control signals from the microprocessor are connected to the gate input of a specified FET transistor. The FET provides low side switch control of the solenoid valves.
[0098] Prior to connecting a cell to the pressure manifold, the pump motor is turned on. The pump is controlled by a signal from the microprocessor that is connected to a FET transistor. The FET provides for low side switch control of the pump motor.
[0099] The system is designed to operate from a rechargeable battery. Separate circuitry provides for controlling the battery charge sequence and monitoring of the battery status. In the event of a low voltage condition, an alarm output is provided to the microprocessor. The system is capable of operating with a charged battery or with a 120 v AC charger attached to the controller.
[0100] An audio alarm is provided to indicate an unrecoverable out of tolerance condition. The frequency and pulse length of the alarm tone are specific to individual alarm conditions, such as low battery voltage, over/under pressure, sensor failure, etc.
[0101] Variations or modifications to the subject matter of this invention may occur to those skilled in the art upon reviewing the disclosure made herein. Such variations, if within the spirit of the desired results to be obtained from usage of this development, are intended to be encompassed within the scope of this invention as defined. The description of the preferred embodiment as set forth herein is done so for illustrative purposes only.
|
A compression garment for selective application for treatment of lymphedema and related illnesses manifested at various locations of the body. The garment includes a pair or series of layers of hermetically sealed material, that can capture pressurized air, when applied therein, and is formed through the patterned sealing of the layers of the garment together, at select locations, to form air pockets that can selectively apply isolated points of pressure to the patient's affected area, without disrupting normal vascular and lymphatic functioning. The garment is design cut, for application to various segments of the body, and applies encompassing pressure over the entire affected area, and includes valves that can allow for the injection of measurable air, to the desired pressure points, or its deflation, after treatment.
| 8
|
This is a continuation of our allowed application Ser. No. 08/760,486 filed Dec. 5, 1996, now U.S. Pat. No. 5,767,880.
FIELD OF THE INVENTION
The present invention relates to so-called "continuous ink jet printers" of the type in which a stream of ink is emitted under pressure from a nozzle and, by the action of a piezoelectric oscillator, is broken up into droplets which can be selectively charged and then deflected in an electric field onto a substrate. Such printers are well known in the art.
Although such printers have been available for many years, problems arise still during the start-up of such a printer. Frequently, the stream of ink issuing from the nozzle is unstable at start-up and this can cause ink to impinge on components of the print head undesirably. In particular, ink impinging on the electrode used to charge the droplets can cause unstable conditions to persist and charging to be inaccurate with the result that droplets are not correctly placed on the substrate.
Also during start-up, there is a need to ensure that guard droplets and non-printable droplets pass correctly into the gutter which is provided for their collection. Additionally, when the printer is of the type in which uncharged droplets are "printed" and charged droplets are either guard drops or non-printable drops, when the printer is first switched on and the stream of ink starts to issue from the nozzle, it is desirable to avoid wastage of ink or the unnecessary application of ink to part of a substrate which will then not be to be used.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a print head for a continuous ink jet printer, the print head having ink supply means for supplying ink under pressure to a nozzle through which ink is emitted in use and broken up into droplets by the action of a piezoelectric oscillator, a charge electrode for applying electrostatic charge to selected droplets in use, a deflection electrode for deflecting the path of charged droplets, and a gutter for collecting droplets not required for printing, wherein the charge electrode or the gutter is movable in a direction transverse to the path of the droplets, the movement being controlled by the action of pressurised ink selectively supplied from the ink supply means to a hydraulic actuator or actuators coupled to the charge electrode or the gutter respectively.
Thus, during start-up, the charge electrode may be withdrawn from its normal operating position laterally to avoid being spattered by ink droplets. The gutter may be positioned so that all droplets issuing from the nozzle during the start-up phase, whether charged or not, pass into the gutter and do not pass to the underlying substrate.
Advantageously, the deflection electrode is mounted for movement with the charge electrode.
The invention also includes a print head constructed such that the charge electrode is moved laterally out of its normal operating position so that it is withdrawn from proximity to the stream of droplets. In a further construction according to the invention, the gutter is laterally moved at start-up so that all droplets issuing from the nozzle, whether charged or not, pass into the gutter.
BRIEF DESCRIPTION OF THE DRAWINGS
One example of a print-head according to the present invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 illustrates the print head in side view, partially cross-sectioned;
FIG. 2 is a partial view of the pressurised ink supply for the printer of FIG. 1; and,
FIG. 3 is a partial view of another pressurised ink supply for the printer of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The print head has an electronics sub-system 1 by means of which are controlled the piezoelectric oscillator in a droplet generator 2, and the application of appropriate voltages to charge electrodes 3 and deflection electrodes 4,4' and by means of which appropriate signals are given to valves 15,16 (not shown in FIG. 1, but see FIGS. 2 & 3) in the printer cabinet (not shown) controlling the flow of ink to the droplet generator 2.
The droplet generator 2 has a nozzle plate 5 with a plurality of closely spaced nozzles arranged in a row (normal to the plane of the drawing) and from which issue, in use, streams of ink 20 (the plane of which is thus normal to the plane of the figure) which, under the action of the piezoelectric oscillator, break up into individual droplets for printing purposes. The droplets pass individual charge electrodes 3 (seen end-on in the drawing), also arranged in a row in the same direction, where they are selectively charged and then passed between the pair of deflection electrodes 4, 4' which establish, in use, an electric field by means of which charged droplets are deflected from their straight-line path into a gutter 6. In the start-up position of the gutter 6 (not shown in the drawing) even uncharged droplets (which in the present case are used for printing) pass into the gutter.
In use ink is supplied from a supply means 14 to an ink chamber (not shown) within the drop generator 2 above the nozzle plate 5, via a feed line 7 and is also supplied to first 8 and second 9 hydraulic actuators, via lines 8" and 9", through the action of the appropriate valves mounted in the printer cabinet (not shown).
The first actuator 8, which is supported on a bracket 10, has a piston 8' which is arranged to bear against one end of a lever arm 11 at the other end of which is mounted the gutter 6. The second actuator 9 is also mounted on the bracket 10 and has a piston 9' which engages, via a pair of links 12, 12', a flexible support bracket 13 for the charge electrodes 3 and the deflection electrode 4.
By selectively operating the valves which control the supply of pressurised ink to the first and second actuators 8, 9 respectively, the gutter 6 can be withdrawn from the "catch-all" position into the position shown in the drawing which is an operating position in which only charged droplets are deflected into the gutter, non-charged droplets being allowed to pass onto the substrate for printing, and the charge electrodes 3 and deflection electrode 4 can be moved rightwards from the position shown in the drawing, to a position in which the charge electrodes 3 are closely adjacent the streams of droplets 20 and the deflection electrode 4 is in the appropriate position relative to the other deflection electrode 4'. This position is defined by an adjustable stop screw 15 which bears against an abutment 16 on the side of the nozzle plate 5.
The start/stop sequence described below uses four solenoid valves; jet, bleed, charge electrode actuator and gutter actuator, none of which are shown in the drawings.
The jet solenoid valve (aka the feed solenoid) is a two-way solenoid valve which is mounted in the print head and controls the flow of ink to the drop generator 2 through the feed line 7.
The bleed solenoid is a similar type of valve to the jet/feed solenoid valve and is also mounted in the print head and controls flow through a bleed line (not shown). When open, it allows a flow of ink through the bleed line from the drop generator 2 primarily to remove ingressed air during start up. During shut down it is also opened to cause a very quick jet shut off by de-pressurising the drop generator. This is helped by connecting the bleed to a vacuum source (not shown) which is used to draw ink from the gutter 6.
The charge electrode actuator valve is a three-port solenoid valve mounted in the ink cabinet. When activated ink is supplied to the actuator 9 so that the charge electrode 3 moves into the print position. When de-activated, the charge electrode 3 returns to its `safe`, jet start position (as shown in the drawing).
The gutter actuator valve is similar to the charge electrode actuator valve and is mounted in the cabinet. When activated, it causes ink to flow to the gutter actuator 8 which moves the gutter 6 into the print position (as shown). When deactivated the gutter 6 is in the "catch all" position needed for jet start up and shut down, rightwards of the position shown in the drawing.
The start up sequence is as follows:
With both the gutter and charge electrode actuator solenoid valves off (the gutter in the catch all position, the charge electrode in the jet start position) the feed pressure and gutter pumps start.
Following a jet start request, the jet solenoid valve opens. The jets start (which causes the pressure to drop). However, the actuators 8,9 require a certain pressure to operate so if the pressure drops below this value the sequence must wait until the pressure reaches this value.
After ten seconds, the bleed valve opens for ten seconds which causes another drop in the pressure. Again, the pressure control system can ignore this drop, so long as it is above the minimum pressure.
Once the bleed valve closes the pressure control system can establish the pressure required for the current operating parameters. Once the correct pressure is established the charge electrodes 3 are moved rightwards into the operating position by activating the charge electrode solenoid valve. At this point, modulation, phasing, jet velocity measurement and charging can start.
Once this has been completed the jets should be being deflected into the back of the gutter 6. At this stage it is safe to move the gutter to the print position shown, by activating the gutter actuator 8. At this stage printing can start.
This sequence is summarised in Appendix A.
The jet stop sequence begins with the gutter actuator 8 closing so that the gutter 6 returns to the catch all position. It is then safe to stop charging, phasing and modulation and move the charge electrodes 3 to the `safe` position by de-activating the charge electrode actuator 9. Like the jet start sequence, the jet stop sequence begins with setting the pressure. Once this has been established the bleed solenoid valve opens. After ten seconds, the jet solenoid valve closes shortly followed by the bleed solenoid valve.
As with the start sequence, the pressure control system need not try to maintain the generating pressure and pressure control faults should be ignored. After the jets have been turned off, the pumps should continue to run, to clear the gutter, before being turned off.
This sequence is summarised in Appendix B.
Although the preferred embodiment utilises the pressurised ink to actuate actuators 15,16 for both the charge electrode(s) 3 and the gutter 6, it should be understood that the pressurised ink can be used to operate either the charge electrode(s) 3 or the gutter 6 independently.
As shown in FIG. 2, a supply of pressurised ink in the supply means 14 is fed via a solenoid valve 15 to the line 9" to operate the charge electrode(s) 3 via the actuator 9. In FIG. 3, the pressurised ink from the supply means 14 is fed to via solenoid valve 16 to the line 8" to operate the gutter 6 via the actuator 8.
Appendix A
Start Up Sequence Summary
Jet On Requested (with pumps already running)
Charge electrode and gutter actuators off
Set feed pressure
Open jet solenoid valve
Wait 10 seconds
Open bleed solenoid valve
Wait 10 seconds
Close bleed solenoid valve
Set the correct pressure for current operating conditions
Turn on charge electrode actuator
Start modulating, charging and phasing
Set correct jet velocity, phase charge etc
Turn on gutter actuator
Turn on green beacon if all ok
Appendix B
Shut Down Sequence Summary
Jet Off Requested (from a printing state)
Turn off green beacon
Turn off gutter actuator
Stop charging and modulation
Turn off charge electrode actuator
Set pressure
Open bleed solenoid valve
Wait 10 seconds
Turn off jet solenoid valve
Wait 200 milliseconds
Turn off bleed solenoid valve
Wait 120 seconds
Turn off pumps
|
A print head for a continuous ink jet printer has a nozzle through which ink is emitted and broken up into droplets under the action of a piezoelectric oscillator. A charge electrode applies charge to selected droplets and a deflection electrode deflects the path of the charged droplets to cause printing on a substrate. A gutter collects droplets which are not required for printing. A charge electrode, together with one of the deflection electrodes is movable in a direction transverse to the path of the droplets selectively under the action of pressurized ink fed from an ink supply. Similarly, the gutter is movable in the same way by another actuator.
| 1
|
TECHNICAL FIELD
[0001] Embodiments described herein are generally directed to the field of semiconductor fabrication.
BACKGROUND
[0002] High dopant activation in source/drain or tip regions of a semiconductor device can significantly improve device performance, i.e., by reducing Rext. Pulsed-laser anneal processes can produce highly active “superactive” regions in a device by melt and rapid regrowth of the doped region. These regions, however, are susceptible to deactivation by subsequent thermal processes.
[0003] While pulsed-laser “melt” anneal processes for source-drain formation are not common in high-volume manufacturing, available literature generally describes a pulsed-laser “melt” anneal process as including pre-amorphizing implant in source/drain (such as a silicon implant), a source-drain implant (such as a phosphorous implant), followed by the pulsed-laser anneal process. The pulsed-laser anneal process is targeted to melt the amorphous material without melting the underlying substrate in which the boundaries of the source and drain are defined by the amorphizing implant conditions. The melt process produces super-activated regions having abrupt, box-like dopant profiles. Another common, closely related technique omits the pre-amorphizing implanting step and relies on fine control of the laser energy to control the depth of the super-active region. Depending on species and precise process parameters, raw activation levels of up to 100% can be achieved.
[0004] One key challenge in integrating such processes is retaining high activation levels through the remainder of the manufacturing process. Deactivation from subsequent thermal processes reduces net activation back towards equilibrium levels in the final product, thereby reducing the overall benefit of the melt-and-anneal process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Embodiments disclosed herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which:
[0006] FIGS. 1A-1H respectively depict process flows for exemplary embodiments of a pulsed-laser anneal process according to the subject matter disclosed herein;
[0007] FIG. 2A is a graph showing exemplary liquid-phase SIMS redistribution data for arsenic (As) concentration for an As-only system as a function of depth for different four laser anneal conditions;
[0008] FIG. 2B is a graph showing exemplary liquid-phase SIMS redistribution data for arsenic (As) concentration for an As—C system as a function of depth for different four laser anneal conditions; and
[0009] FIG. 3 is a graph showing exemplary liquid-phase SIMS redistribution data for carbon concentration for the As—C system as a function of depth for four different laser anneal conditions.
[0010] It will be appreciated that for simplicity and/or clarity of illustration, elements depicted in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. The scaling of the figures does not represent precise dimensions and/or dimensional ratios of the various elements depicted herein. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.
DETAILED DESCRIPTION
[0011] Embodiments of techniques described herein relate to semiconductor fabrication and, more particularly, to fabricating superactive deactivation-resistant semiconductor junctions. In the following description, numerous specific details are set forth to provide a thorough understanding of embodiments disclosed herein. One skilled in the relevant art will recognize, however, that the embodiments disclosed herein can be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the specification.
[0012] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. Additionally, the word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not to be construed as necessarily preferred or advantageous over other embodiments.
[0013] Various operations may be described as multiple discrete operations in turn and in a manner that is most helpful in understanding the claimed subject matter. The order of description, however, should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation. Operations described may be performed in a different order than the described embodiment. Various additional operations may be performed and/or described operations may be omitted in additional embodiments.
[0014] The subject matter disclosed herein relates to semiconductor fabrication and; more particularly, to fabricating superactive deactivation-resistant semiconductor junctions.
[0015] The subject matter disclosed herein relates to a method to create a superactive junction that is resistant to deactivation from subsequent thermal processes.
[0016] The subject matter disclosed herein utilizes a liquid-phase redistribution of a multicomponent system that improves resilience against deactivation. An exemplary embodiment of the subject matter disclosed herein involves a pulsed-laser anneal process in which the melted region contains both the donor species and one or more co-constituents.
[0017] There are at least eight variations of the pulsed-laser anneal process disclosed herein, which are respectively depicted in FIGS. 1A-1H . For the following exemplary embodiments, any or all implant processes may refer to a conventional beam line ion implantation, an angled implantation or a conformal-plasma implantation to address issues associated with nonplanar geometries. Additionally, one or more conventional annealing processes (e.g., furnace, RTP, or millisecond anneal) may be inserted into the flow. These particular anneals may serve purposes, such as defect reduction, partial regrowth, pre-activation, or dopant profile modification.
[0018] Because the subject matter disclosed herein is confined to a short and specific segment of an overall process flow, it expected that the techniques disclosed herein are be compatible with a wide variety of global process options. Implementation of the exemplary processes disclosed herein are be independent of the following parameters: (1) substrate type (e.g., compatible with BULK and SOI processes, and is independent of substrate orientation); (2) transistor architecture (e.g., compatible with planar and nonplanar architectures); (3) gate/gate oxide strategy (e.g. compatible with SiO 2 /poly and both gate-first/gate-last high-k/MG processes); and (4) pulsed-laser anneal integration scheme (e.g., compatible with ARC, absorber strategies).
[0019] FIG. 1A is a flow diagram 110 depicting a first exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein is an implant-only process. At 111 in FIG. 1A , a pre-amorphizing implant is performed. The order of the implants is not critical. At 112 , a source/drain implant is performed. At 113 , a co-constituent, such as carbon, is implanted. Other exemplary co-constituents include antimony (Sb), tin (Sn) and fluorine (F), and selection of a particular co-constituent to form a superactive region that is deactivation resistant depends on the particular active dopant species as well as the particular semiconductor. At 114 , a pulsed-laser anneal process is performed.
[0020] FIG. 1B is a flow diagram 120 depicting a second exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The second exemplary embodiment is similar to the first exemplary embodiment, but omits the pre-amorphizing implant, in which case the boundaries of the melted region are defined by fine control of the laser energy applied during the pulsed-laser anneal process. At 121 in FIG. 1B , a source/drain implant is performed. At 122 , a co-constituent, such as carbon, is implanted. At 123 , a pulsed-laser anneal process is performed.
[0021] FIG. 1C is a flow diagram 130 depicting a third exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The third exemplary embodiment utilizes an insitu-doped source-drain process in place of the source-drain implant process used in the first exemplary embodiment ( FIG. 1A ). In particular, at 131 in FIG. 1C , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu source-drain doping. The order of the insitu implants is not critical for the third exemplary embodiment. At 132 , a co-constituent, such as carbon, is implanted. At 133 , a pre-amorphizing implant is performed. At 134 , a pulsed-laser anneal process is performed.
[0022] FIG. 1D is a flow diagram 140 depicting a fourth exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The fourth exemplary embodiment is similar to the third exemplary embodiment, but omits the pre-amorphizing implant, in which case the boundaries of the melted region are defined by fine control of the laser energy applied during the pulsed-laser anneal process. At 141 in FIG. 1D , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu source-drain doping. The order of the insitu implants is not critical for the fourth exemplary embodiment. At 142 , a co-constituent, such as carbon, is implanted. At 143 , a pulsed-laser anneal process is performed.
[0023] FIG. 1E is a flow diagram 150 depicting a fifth exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The fifth exemplary embodiment utilizes an insitu-doped source-drain process in place of the source-drain implant process that is used in the third exemplary embodiment ( FIG. 1C ). At 151 in FIG. 1E , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu (non-donor) source-drain doping. The order of the insitu implants is not critical for the fifth exemplary embodiment. At 152 , a source/drain implant is performed. At 153 , a pre-amorphizing implant is performed. At 154 , a pulsed-laser anneal process is performed. FIG. 1F is a flow diagram 160 depicting a sixth exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The sixth exemplary embodiment is similar to the fifth exemplary embodiment, but omits the pre-amorphizing implant, in which case the boundaries of the melted region are defined by fine control of the laser energy applied during the pulsed-laser anneal process. At 161 , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu (non-donor) source-drain doping. The order of the insitu implants is not critical for the sixth exemplary embodiment. At 162 , a source/drain implant is performed. At 163 , a pulsed-laser anneal process is performed.
[0024] FIG. 1G is a flow diagram 170 depicting a seventh exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The seventh exemplary embodiment is similar to the third exemplary embodiment ( FIG. 1C ), but differs by having all implants replaced by insitu doping. At 171 , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu implant of donor and co-constituent source-drain doping. The order of the insitu implants is not critical for the seventh exemplary embodiment. At 172 , a pre-amorphizing implant is performed. It should be understood that in an alternative exemplary embodiment, the pre-amorphizing implant could be performed prior to the insitu implant of donor and co-constituent source-drain doping. At 173 , a pulsed-laser anneal process is performed.
[0025] FIG. 1H is a flow diagram 180 depicting an eighth exemplary embodiment of a pulsed-laser anneal process according to the subject matter disclosed herein. The eighth exemplary embodiment is similar to the seventh exemplary embodiment ( FIG. 1G ), but omits the pre-amorphizing implant, in which case the boundaries of the melted region are defined by fine control of the laser energy applied during the pulsed-laser anneal process. At 181 , a chemical vapor deposition (CVD) source/drain deposition, for example, is performed with insitu of donor and co-constituent source-drain doping. The order of the insitu implants is not critical for the eighth exemplary embodiment. At 182 , a pulsed-laser anneal process is performed. The effectiveness of the subject matter disclosed herein has been demonstrated on As-implanted blanket wafers with and without carbon as a co-constituent. The process flow for the As-only system included deep p-well implants and activation followed by a 12 keV 7×10 14 silicon pre-amorphizing implant, and a 10 keV 4.8×10 15 As implant. Process flow for the As—C system was the same and carbon was added by two successive implants at 4 keV 2 keV to achieve ˜1% total C concentration.
[0026] FIG. 2A is a graph showing exemplary liquid-phase SIMS redistribution data for arsenic (As) concentration for the As-only system as a function of depth for different four laser anneal conditions. The ordinate of FIG. 2A is As concentration measured as As atoms/cm 3 , and the abscissa of FIG. 2A is depth in Ångstroms. The four laser anneal conditions are (1) no anneal shown at 201 , pulsed-laser anneal using 500 mJ/cm 2 shown at 202 ; pulsed-laser anneal using 550 mJ/cm 2 shown at 203 ; and pulsed-laser anneal using 600 ml/cm 2 shown at 204 . FIG. 2B is a graph showing exemplary liquid-phase SIMS redistribution data for arsenic (As) concentration for the As—C system as a function of depth for different four laser anneal conditions. The ordinate of FIG. 2B is As concentration measured as As atoms/cm 3 , and the abscissa of FIG. 2B is depth in Ångstroms. The four laser anneal conditions are no anneal shown at 211 , pulsed-laser anneal using 500 mJ/cm 2 shown at 212 ; pulsed-laser anneal using 550 mJ/cm 2 shown at 213 ; and pulsed-laser anneal using 600 mJ/cm 2 shown at 214 . FIG. 3 is a graph showing exemplary liquid-phase SIMS redistribution data for carbon (C) concentration for the A-C system as a function of depth for four different laser anneal conditions. The ordinate of FIG. 3 is As concentration measured as C atoms/cm 3 , and the abscissa of FIG. 3 is depth in Ångstroms. Again, the four laser anneal conditions are no anneal shown at 301 , pulsed-laser anneal using 500 mJ/cm 2 shown at 302 ; pulsed-laser anneal using 550 mJ/cm 2 shown at 303 ; and pulsed-laser anneal 600 mJ/cm 2 shown at 304 . Table 1 shows the sheet resistance (Rs) and absolute active-carrier concentration after pulsed-laser anneal and a series of subsequent deactivating anneals (i.e., 700 C spike anneal plus 300 C one-hour furnace anneal).
[0000]
TABLE 1
Rs
[Active
(Ω/cm 2 )
Carrier]/cm 2
Enhancement
As
223.38
2.17 × 10 20
N/A
As + C
194.55
2.93 × 10 20
35%
[0027] Both the As-only system and the As+C system have a concentration of As of approximately 1.6×10 21 atoms/cm 3 and junction depth Xj (i.e., the depth at which the concentration of As drops below 1×10 19 atoms/cm 3 ) of approximately 30 nm. After annealing, the liquid-phase redistribution of As+C system according to the subject matter disclosed herein exhibits activation enhanced of about 35% over the As-only system.
[0028] These modifications can be made in light of the above detailed description. The terms used in the following claims should not be construed to limit the scope to the specific embodiments disclosed in the specification and the claims. Rather, the scope of the embodiments disclosed herein is to be determined by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
|
A pulsed-laser anneal technique includes performing an implant of a selected region of a semiconductor wafer. A co-constituent implant of the selected region is performed, and the pulsed-laser anneal of the selected region performed. A pre-amorphizing implant of the selected region can also be performed. In one embodiment, the implant of the selected region is performed as an insitu implant. In another embodiment, the co-constituent implant is performed as an insitu non-donor implant. In yet another embodiment, the implant and the co-constituent implant of the selected region are performed as an insitu donor and co-constituent implant.
| 7
|
FIELD OF THE INVENTION
[0001] This invention relates to an electronic device for increasing an extremely low DC voltage to a voltage suitable for operating other electronic devices. More particularly it relates to an electronic device usable for increasing the extremely low voltage generated by a transducer which converts heat energy of the flame of a pilot light of a gas equipment such as a gas fireplace and the like to an electrical power suitable for operating the electrical control of the gas supply to the gas equipment.
BACKGROUND OF THE INVENTION
[0002] The gas supply to the main burner of a gas equipment is controlled by an electrically operated solenoid valve. Such valve is commonly operated with a voltage supply of 6 to 9 volts DC in order to reduce the potential fire hazard for operating it in the explosive gas environment if it is operated with a higher voltage. The solenoid valve may be actuated with a manual switch or an electronic remote control device. The operating electrical power of the electronic remote control device, also is commonly in the range of 6 to 9 volts supplied by either a battery or by power obtained through a step-down voltage supply from an AC current source. Wiring of an AC source to the receiver of the remote control device is often difficult to make due to the installation location of the gas equipment particularly when the gas equipment is situated in a building having a finished wall construction. Battery may be used to provide the electrical power for operating the remote control receiver for ease in installation. However, the drawback of a battery supply is that the battery requires replacement from time to time as its power depletes, especially when its power would deplete in a much faster rate in a hot environment during the operation of the gas equipment. Moreover, users of the gas equipment are unwilling to perform such task of replacing the battery due to either the fear of might accidentally cause a fire hazard in the explosive gas environment or being unfamiliar with the gas equipment. More often the user would neglect to replace the battery so that the gas equipment becomes inherently inoperative.
SUMMARY OF THE INVENTION
[0003] It is the principal object of the present invention to provide an electronic device operable for increasing extremely low DC voltage to a voltage suitable for operating electronic devices.
[0004] It is an object of the present invention to provide a power source for operating the remote control switch of the solenoid valve a gas equipment by utilizing the heat energy of its pilot light.
[0005] It is another object of the present invention to provide a conversion device which is capable of converting heat energy of the pilot light burner of a gas equipment to electrical power in the magnitude suitable for operating electronic control devices of the gas equipment.
[0006] It is another object of the present invention to provide an electronic device for converting heat energy to a substantially constant electrical power source for operating the gas supply control solenoid valve of a gas equipment.
[0007] It is yet another object of the present invention to provide a heat to electrical power supply conversion device which is simple in construction and easy to incorporate in a natural gas equipment installation.
[0008] These and other objects are achieved by my invention. The structure and some of its' various modes of operation may be understood by reference to the drawings taken in conjunction with the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a schematic circuit diagram of the electrical circuit of the device according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] With reference to the drawing, the electronic device 10 of the present invention has an oscillation circuit having two MOSFET transistors 11 and 12 connected in tandem and coupled with a multi-winding transformer 13 which has four bifilar windings 14 , 15 , 16 and 17 . The four bifilar windings are wound on a core having a very high permeability so as to provide a good coupling between the windings. The numbers of windings in windings 14 and 15 are equal to one another and the numbers of windings of windings 16 and 17 are equal to one another and is much higher than those of windings 14 and 15 . The start of the winding 14 is connected to the end of the winding 16 at a first connection terminal 18 , and the end of the winding 14 is connected to the start of the winding 15 at a second connection terminal 19 , whereas the end of the winding 15 is connected to the start of the winding 17 at a third connection terminal 20 . The start of the windings 14 , 15 , 16 and 17 is indicated in the drawing with a dot. The source terminals 18 and 19 for the transistors 11 and 12 respectively are connected to one another. The source terminals 21 and 22 of the transistors 11 and 12 respectively are connected to a common terminal 23 . The drain terminal 24 of the transistor 11 is connected to the first connection terminal 18 and the drain terminal 25 of transistor 12 is connected to the connection terminal 20 . The gate terminal 26 of the transistor 11 is connected to the end of winding 17 through a resistor 27 while the gate terminal 28 is connected to the start of the winding 16 through a resistor 29 similar to resistor 27 . The head of transformer winding 16 is connected to the anode of a first Schottky diode 30 and the cathode of a second Schottky diode 31 through a capacitor 32 . Similarly, the end of transformer winding 17 is connected to the anode of a third Schottky diode 33 and the cathode of a four Schottky diode 34 through a capacitor 35 . The parallel diode circuit provides a full wave rectification to the voltage outputted from the oscillation circuit.
[0011] The above oscillation circuit is operable by an extremely low DC voltage as low as about 0.15 volt which is too low to operate common transistors. The extremely low voltage is inputted to connection terminal 19 and common terminal 23 . Due to the extremely low voltage, the oscillator circuit initially would not be actuated by the low voltage; in order to initiate the operation of the oscillation circuit, a short circuit operation is made by a momentary switch 38 connected across the source terminal 21 and drain terminal 24 of the transistor 11 . When the momentary switch 38 is closed and then opened, the output first voltage across the drain to common terminals of the transistor 11 will be at least double of that of the extremely low input DC voltage; and this first voltage will induce a much higher first secondary voltage across the winding 16 by the transformer action due to the much higher number of windings of winding 16 relative to the winding 14 . This first secondary voltage will be applied to the gate terminal 28 through resistor 29 to present an increased voltage to turn on the transistor 12 so that the transistor 12 begins to conduct. The conduction of current through the transistor 12 will continue until the current saturates the core of the transformer 13 at which point the transistor 12 will turn off. The termination of conduction of the transistor 12 will generate a second secondary voltage across the winding 17 by the transformer action due the much higher number of windings of the winding 17 relative to the winding 15 . The second secondary voltage will be applied inherently to the transistor 11 to turn the later on. In this manner, the transistors 11 and 12 are turned on and off with one transistor turning on while the other transistor turning off, in a continuous cycle. The combination of diodes 30 and 31 and capacitor 32 forms a first doubling circuit to provide a voltage doubling function to the first secondary voltage across the winding 13 , while the combination of diodes 33 and 34 and capacitor 35 provides a second voltage doubling circuit to provide a voltage doubling function to the second secondary voltage across the winding 17 . The two doubling circuits also provide a full wave rectification to the combined first secondary voltage and second secondary voltage appearing at terminals 26 and 37 . This combined high voltage is further smoothed by the capacitor 38 connected across the terminals 26 and 37 . The high voltage has sufficient current and a high efficiency. It is also very economical to build as it does not require a special winding for the high voltage output. The feedback windings 16 and 17 are used in the dual purposes to provide a full load current.
[0012] The smooth output voltage across the terminals 26 and 37 to a stabilization circuit including FET transistor 39 and a zener diode 40 connected in series across the output terminals. A potentiometer 41 is connected between the gate of transistor 39 and the anode of the zener diode 40 . The potentiometer 41 may be adjusted to vary the amount of current flowing through the drain terminal to the source terminal of the FET transistor 39 into the zener diode 40 while the output voltage is maintained substantially constant.
[0013] It would be appreciated by those skilled in the art that alternatively P-channel MOSFET transistor may be used instead of the N-channel MOSFET transistor by changing the polarity and connection of the diodes and the junction FET transistor.
[0014] The above circuit device is suitable for increasing the extra low DC voltage obtained from a thermopile heated by the pilot light flame of a gas equipment. Such extra low DC voltage is not suitable for operating the electrical control of the gas supply to the main burner of a gas equipment. With the device of the present invention, the extra low voltage is increased to the suitable voltage for operating the gas control solenoid valve and the remote control circuit of the gas supply to the main burner.
[0015] While the preferred embodiment of the invention has been disclosed, it should be appreciated that the invention is susceptible of modification without departing from the scope of the following claims.
|
A device for increasing an extreme low voltage from a heat to electrical voltage thermopile is shown. The device has an oscillator including two MOSFET transistors coupled to a transformer having four bifilar windings wound on a core having a high permeability. The two transistors operate alternately to generate an intermediate voltage which is increased in magnitude by a voltage doubling and rectifying circuit to obtain the substantially constant operating output voltage. The output voltage is further maintain constant by a current control cirucit including an adjustable potentiometer adjustable to vary the current.
| 7
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to implantable power sources, and more particularly to a bio-implantable electrochemical cell system for providing high power for active implantable medical devices.
[0003] 2. Description of the Prior Art
[0004] Implantable power sources for cardiac pacemakers, defibrillators, implantable diffusion pumps, neurostimulators and other active implantable medical devices have contributed to the health of millions of patients during the past few decades. During this same period, there have been increasing pressures to reduce healthcare costs by reducing hospital and in-patient stays without compromising the quality of patient care. The result has been an increase in the numbers of out-patients who rely on active implantable medical devices to maintain and/or improve their health.
[0005] An active implantable medical device is defined as any active device which is intended to be totally or partially introduced, surgically or medically, into the human body or by medical intervention into a natural orifice, and which is intended to remain after the procedure.
[0006] For example, a cardiac pacemaker is an active implantable medical device that uses a steady electrical pulse to regulate the beating of the human heart. The first cardiac pacemaker was invented by John Hopps in 1950, but this device was far too large to be implanted inside the human body. The first implantable cardiac pacemaker and corrosion-free lithium battery was invented by Wilson Greatbatch in the late 1950's (U.S. Pat. No. 3,057,356 issued Oct. 9, 1962).
[0007] The cardiac pacemaker is implanted in the chest cavity, near the heart, and is used to correct slow ventricular rate (bradycardia), high ventricular rate (atrial fibrillation or flutter), and arrhythmia. Patients having these heart pacing abnormalities have a defective sinoatrial node and are unable to maintain a regular heartbeat. Modern cardiac pacemakers control both the ventricles and the atria of the heart, by timing the contraction of the atria to proceed that of the ventricles, thereby improving the pumping efficiency of the heart. These devices are particularly useful for patients suffering from congestive heart failure.
[0008] All cardiac pacemakers require a source of electrical power to function. Most cardiac pacemakers use implantable lithium batteries that are implanted with the pacemaker; however, they have the disadvantage of requiring an additional surgery every 24 months to replace the battery. The power requirements of the cardiac pacemaker are typically in the microampere range.
[0009] By contrast, the coronary stent is an example of a passive implantable medical device. A coronary stent consists of metal wires, usually stainless steel, nitinol or other metal alloy, that is used to remove blockage of coronary arteries. The stent is wrapped around a deflated balloon and surgically advanced to the site of the coronary artery blockage. The balloon is then inflated and the stent expands, pressing the blockage tissue against the wall of the artery and restoring the blood flow to the heart. In this procedure, called balloon angioplasty, there is no power source required for insertion of the coronary stent.
[0010] Another example of an active implantable medical device is the implantable drug infusion pump, which delivers therapeutic plasma levels of an active drug to a target organ or body compartment for prolonged periods of time. There exist both programmable and non-programmable drug infusion pumps. In the former the bulk drug flow is generated by direct mechanical action powered by a battery, while in the latter the flow is generated by a fluorocarbon propellant. The pump is surgically implanted in a subcutaneous pocket and connects to a dedicated catheter that has been placed in the appropriate compartment. Constant or variable rates of infusion are possible over long periods of time with minimal human intervention; however, in the case of programmable drug infusion pumps, the battery must eventually be replaced. The power requirements of the implantable drug infusion pump are typically in the milliampere range.
[0011] An example of an implantable drug infusion pump is the implantable insulin pump used to deliver insulin into patients with diabetes, in order to maintain their blood sugar, or glucose, at a constant level.
[0012] Most active implantable medical devices have been powered primarily by lithium/iodine or lithium/carbon monoflouride batteries. Lithium/iodine batteries are typically used to generate currents in the microampere range, while lithium/carbon monoflouride batteries can generate currents in the milliampere range. During the last few decades, the size of active implantable medical devices and the power consumption of their complementary metal-oxide semiconductor (CMOS) electronic circuits have been continually reduced. At the same time, the size and weight of the power sources for these devices have not been proportionally reduced, primarily due to the difficulty of miniaturizing the case and seal of the power source. At the same time, the case and seal are necessary for a battery since the lithium anode will oxidize in a humid environment, and the alkakine electrolyte of zinc-silver oxide batteries is highly corrosive.
[0013] As mentioned above, another difficulty with batteries as a power source for active implantable medical devices is the requirement of periodic recharging or replacement. This is particularly difficult in situations where the battery is contained within the implanted device, because surgery is required to remove and replace the battery. The alternative of having the power source located outside the body is equally problematic, since the point where the power leads enter the body is also subject to infection. Any situation in which an invasive procedure is used can lead to infection and other more serious medical complications.
[0014] The power requirements of different implantable devices vary from microamperes for cardiac pacemakers to milliamperes for drug infusion pumps and neurostimulators to amperes for cardiac defibrillators. These increasing power requirements lead directly to an increasing size and weight in power source that makes implanting of the latter impossible.
[0015] In addition to the above-discussed existing active implantable medical devices, the nascent fields of nanotechnology and nanomedicine are focused on developing and deploying implantable, molecular-scale machines and devices for the prevention and treatment of disease in the human body. For example, the most elemental nanomedical devices will be used to diagnose illness by monitoring the internal chemistry of the body. Currently under development by many researchers are mobile nanorobots, equipped with wireless transmitters, that might circulate in the blood and lymph systems and send out warnings when chemical imbalances occur or worsen. Similarly, fixed nanomachines may be implanted in the nervous system to monitor pulse, brain wave activity, and other neurological functions.
[0016] A more advanced use of nanotechnology in medicine might be the use of implanted, molecular-sized devices to dispense drugs or hormones at the cellular level. Ultimately artificial antibodies, artificial red and white blood cells, and antiviral nanorobots might be developed and deployed.
[0017] The most advanced nanomedicine might involve the use of nanorobots as miniature surgeons. The active implanted devices might repair damaged cells; or get inside of cells to replace or assist damaged intracellular structures. At the extreme, nanomachines might replicate themselves or correct genetic deficiencies by altering or replacing DNA molecules.
[0018] Most of these new nanotechnology devices will be active implantable devices that will require a miniature, implantable power source that does not need to be recharged or otherwise maintained.
[0019] Accordingly, there is a need for a bio-implantable electrochemical cell that derives its power from blood or other body fluids, has no mechanical or moving parts, has no hazardous electrolytes requiring a sealed case, is biologically compatible, and does not require external recharging or replenishment.
SUMMARY OF THE INVENTION
[0020] The present invention is directed to a bio-implantable electrochemical cell system for providing high power for active implantable medical devices. The electrochemical cell of the present invention provides an order of magnitude improvement in power density (1,000 to 10,000 μW cm −2 ) over existing glucose/oxygen fuel cells, with a total output power of 1,000 to 10,000 μW. The output of the present invention is sufficient to power many conventional active implantable medical devices, including cardiac pacemakers, neurostimulators, and drug infusion pumps.
[0021] In a first embodiment of the present invention, the electrochemical cell includes a novel electrode structure consisting of immobilized anode and cathode enzymes deposited on nanostructured high-surface-area gold electrodes. The anode enzyme may comprise immobilized glucose oxidase and the cathode enzyme may comprise immobilized laccase. Glucose is oxidized in a half-reaction at the surface of the anode electrode by the glucose oxidase to form gluconolactone, plus two hydrogen ions (protons) and two electrons. Oxygen plus four hydrogen ions and four electrons are reduced in a half-reaction at the surface of the cathode electrode by the laccase to form two water molecules. The coupled glucose oxidation-oxygen reduction half-reactions provide an efficient, stable, and self-generating current source.
[0022] The nanostructured high-surface-area gold electrodes are formed on silicon or aluminum substrates to form the anode and cathode. In the first embodiment of the present invention, the electrodes are fabricated using a conventional template process in which the pores of an anodized alumina template are filled with gold by electrodeposition. The alumina template is formed by sputtering or evaporating a thin seed layer of gold followed by a layer of aluminum on a silicon, glass or aluminum substrate. The aluminum substrate is then electro-polished to remove surface defects and anodized which generates the pores and converts the aluminum to alumina. The size of the alumina template pores is controlled by adjusting the anodizing parameters, including the solution composition, operating temperature, and applied voltage.
[0023] After the pores have been formed and widened by the anodizing process, gold nanowires are formed in each of the pores by conventional electrodeposition. As mentioned above, the precise number and size of the pores, and therefore the precise number of nanowires that are fabricated depends on the careful control of the anodizing parameters. Once the pores have been filled with gold via the electrodeposition process, the anodized alumina template is chemically dissolved, leaving an array of nanostructured gold electrodes bonded to the silicon, aluminum or glass substrate.
[0024] The above template process results in an electrode having typical dimensions of 4 μM 2 and containing an array of approximately 1600 gold nanowires, with the exact number determined by the parameters of the anodizing process. In the first preferred embodiment fabricated according to the present invention, the estimated active reacting surface of each electrode is approximately 680 cm 2 compared to a flat surface area of 0.78 cm 2 .
[0025] After the anodized alumina template is chemically dissolved, the gold nanowires and adjacent surface anode and cathode electrodes are coated with immobilized glucose oxidase and immobilized laccase, respectively, using a conventional Langmuir-Blodgett lift-off process. Using this process, one or more thin layers of immobilized enzyme are deposited onto the nanowires and adjacent surface of each electrode, resulting in the precise construction of enzyme architectures with control at the molecular level. In the present invention, the enzyme activity of both the glucose oxidase and laccase are improved using a pyrroloquinoline quinone (PQQ) mediated glucose oxidase system for the anode, with a tree-derived laccase for oxygen reduction at the cathode.
[0026] In the first embodiment of the present invention, a single electrochemical cell is formed from an anode and a cathode fitted in a bio-compatible housing with a porous membrane. The porous membrane excludes macromolecules and other constituents of the plasma from the interior of the fuel cell, while being permeable to glucose, oxygen, water and ions. The glucose and water molecules are therefore able to flow into the interior of the fuel cell to react with the immobilized enzymes of the anode and cathode, respectively. The anode and cathode are separated by an insulator of, for example, silicon dioxide, thereby allowing the electrons to accumulate on the cathode and positive charges to accumulate on the anode.
[0027] The amount of steady-state current generated by the electrochemical cell of the present invention is a function of the steady-state reaction rates of the oxidation and reduction processes. The reaction rates, in turn, depend primarily on the total reactive surface area of the anode and cathodes and the concentration of glucose and oxygen inside the cell. In the preferred embodiment, the total available power generated by the electrochemical cell ranges from 1000 μW to 10,000 μW.
[0028] In a second embodiment of the present invention, the novel electrode structure of the electrochemical cell consists of immobilized enzyme on nanostructured high-surface-area carbon nanotube electrodes. The nanostructured high-surface-area carbon nanotube electrodes are also formed on silicon or aluminum substrates to form the anode and cathode. The electrodes are fabricated using the above anodized alumina template process, but in this case the carbon nanotubes are formed inside the pores by chemical vapor deposition.
[0029] In accordance with the second embodiment of the present invention, the alumina template is again formed by sputtering or evaporating a thin seed layer of gold followed by a layer of aluminum on a silicon, glass or aluminum substrate. The aluminum substrate is then electro-polished to remove surface defects and anodized which generates the pores and converts the aluminum to alumina. As discussed in connection with the first embodiment of the present invention, the size of the alumina template pores is controlled by adjusting the anodizing parameters, including the solution composition, operating temperature, and applied voltage.
[0030] After the pores have been formed and widened by the anodizing process, a thin catalyst layer of nickel, iron, or cobalt is formed in each of the pores by electrodeposition. As mentioned above, the precise number and size of the pores, and therefore the precise number of carbon nanotubes that are fabricated depends on the careful control of the anodizing parameters. Once the pores have been filled with the catalyst, carbon nanotubes are grown in each pore, again using chemical vapor deposition. After the carbon nanotubes have been formed, the anodized alumina template is chemically dissolved, leaving an array of carbon nanotubes bonded to the silicon, aluminum or glass substrate.
[0031] The above template process results in an electrode having typical dimensions of 4 μM 2 and containing an array of approximately 1600 carbon nanotubes, with the exact number determined by the parameters of the anodizing process as previously described. In the second preferred embodiment fabricated according to the present invention, the estimated active reacting surface of each electrode is again approximately 680 cm 2 compared to a flat surface area of 0.78 cm 2 , with the advantage of the superior tensile strength, conductivity, chemical inertness and biocompatibility of carbon.
[0032] After the anodized alumina template is chemically dissolved, the carbon nanotubes and adjacent surface anode and cathode electrodes are coated with immobilized glucose oxidase and immobilized laccase, respectively, using a conventional Langmuir-Blodgett lift-off process as described in connection with the first embodiment of the present invention.
[0033] A single electrochemical cell is then fabricated from an anode and a cathode fitted in a bio-compatible housing with a porous membrane. The amount of steady-state current generated by the electrochemical cell of the second embodiment of the present invention is again a function of the steady-state reaction rates of the oxidation and reduction processes. The reaction rates, in turn, depend primarily on the total reactive surface area of the anode and cathodes and the concentration of glucose and oxygen inside the cell, both of which are the same as for the gold nanowire-based electrodes of the first embodiment described herein.
[0034] A third embodiment of the present invention is similar to the first embodiment, except that the novel electrode structure consists of immobilized enzyme on nanostructured high-surface-area titanium electrodes instead of gold electrodes. The above-described electrodeposition process is used to form the titanium nanowires in a manner identical to the method used to form the gold nanowires. All of the electrical and operational properties of the third embodiment of the present invention are similar to those of the first embodiment of the present invention.
[0035] In a fourth embodiment of the present invention, the nanowires or carbon nanotubes of the first, second and third embodiments, along with the adjacent surface anode and cathode electrodes are coated with spherical biocolloidal substrates containing immobilized glucose oxidase and immobilized laccase, respectively, using a modified Langmuir-Blodgett lift-off process. Using this process, one or more thin layers of biocolloidal substrates are deposited onto the nanowires or carbon nanotubes and adjacent surface of each electrode, resulting in the precise construction of an enzyme architecture with control at the molecular level, while increasing the reactive surface area by one to two orders of magnitude over the first, second, or third embodiments.
[0036] As stated above in connection with the first embodiment of the present invention, the reaction rates determine the amount of power generated by the fuel cell. These rates depend primarily on the total reactive surface area of the anode and cathodes and the concentration of glucose and oxygen inside the cell. In the fourth embodiment of the present invention, the reactive surface area and the total available power generated by the electrochemical cell are both increased by one to two orders of magnitude.
[0037] The first, second, third, or fourth embodiments of the present invention may also include two or more electrochemical cells connected in series to generate higher voltages.
[0038] The first, second, third, or fourth embodiments of the present invention may further include two or more electrochemical cells connected in a series-parallel configuration for generating higher voltages and currents.
[0039] Further features and advantages of the present invention will be appreciated by a review of the following detailed description of the preferred embodiments taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The present invention may be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein like numerals denote like elements and in which:
[0041] FIG. 1A is a first configuration of a single electrochemical cell 100 constructed in accordance with the principles of the present invention;
[0042] FIG. 1B is a second configuration of a single electrochemical cell 150 constructed in accordance with the principles of the present invention;
[0043] FIGS. 2A and 2B show the steps of a process 200 for fabricating arrays of gold or titanium nanostructured rods 106 , 108 , 156 , and 158 , using electrodeposition in accordance with the present invention;
[0044] FIGS. 3A and 3B show the steps of a process 300 for fabricating arrays of carbon nanotubes 106 , 108 , 156 , and 158 , using chemical vapor deposition in accordance with the present invention;
[0045] FIG. 4 shows the steps of a first process 400 for forming the immobilized enzyme layers of the anode and cathode, in accordance with the first, second, and third embodiments of the present invention;
[0046] FIGS. 5A-5C show the steps of a second process 500 for forming immobilized enzyme layers, comprising biocolloidal substrates containing silica nanoparticles, of the anode and cathode, in accordance with the fourth embodiment of the present invention;
[0047] FIG. 6 is a functional schematic 600 showing the glucose oxidation and oxygen reduction reactions of electrochemical cell 100 of the present invention;
[0048] FIG. 7 is a functional schematic 700 of three electrochemical cells connected in series to provide an increased output voltage;
[0049] FIG. 8 is a functional schematic 800 of six electrochemical cells connected in series parallel to provide an increased output voltage and current; and
[0050] FIG. 9 is a functional schematic 900 of a complete bio-chip system with integrated power source, communicate module, sensor array, CPU control module, simulation array.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] The following exemplary discussion focuses on a bio-implantable electrochemical cell system for providing high power for active implantable medical devices. The apparatus of the present invention provides an order of magnitude improvement in power density (1,000 to 10,000 μW cm −2 ) over existing glucose/oxygen fuel cells, with a total output power of 1,000 to 10,000 μW.
[0052] Referring to FIG. 1A , a first configuration of a single electrochemical cell 100 constructed in accordance with the principles of the present invention, is shown. Electrochemical cell 100 comprises an anode 102 and a cathode 104 , both including arrays of nanostructured rods 106 and 108 in their respective interior portions. Immobile enzyme layers 110 and 112 are deposited on the interior surfaces of anode 102 and cathode 104 , respectively, including on the arrays of nanostructured rods 106 and 108 . Immobile enzyme layer 110 comprises glucose oxidase and is deposited on the interior surface and nanostructured rods of anode 102 . Immobile enzyme layer 112 comprises laccase and is deposited on the interior surface and nanostructured rods of cathode 104 .
[0053] In the preferred embodiments of the present invention, the dimensions of anode 102 and cathode 104 are four microns by four microns. The dimensions of each rod of nanostructured arrays 106 and 108 are two microns in height with a diameter of 500 angstroms, with each rod being composed of gold, titanium, or carbon nanotube. The thickness of the deposited immobilized enzyme layers is approximately 200 angstroms, or less.
[0054] Continuing with FIG. 1A , anode 102 and cathode 104 are positioned within a housing 114 in a side-by-side configuration, separated by an electrically insulating material 116 such as silicon dioxide. Housing 114 is constructed from an inert bio-compatible material such as teflon, and includes a porous membrane 118 on a side opposite anode 102 and cathode 104 . Porous membrane 118 is designed to allow glucose and oxygen molecules to enter the interior of electrochemical cell 100 , and to exclude all other macromolecules.
[0055] Referring now to FIG. 1B , a second configuration of a single electrochemical cell 150 , is shown. Electrochemical cell 150 also comprises an anode 152 and a cathode 154 , both including arrays of nanostructured rods 156 and 158 in their respective interior portions. As with electrochemical cell 100 , an immobile enzyme layer 160 comprising glucose oxidase is deposited on the interior surface and nanostructured rods 156 of anode 152 , and an immobile enzyme layer 162 comprising laccase is deposited on the interior surface and nanostructured rods 158 of cathode 154 . The dimensions of anode 152 and cathode 154 , along with nanostructured rods 156 and 158 , are substantially similar to those of anode 102 and cathode 104 of electrochemical cell 100 , discussed above.
[0056] In the configuration of electrochemical cell 150 , anode 152 and cathode 154 are positioned within opposite ends of a housing 164 . Housing 164 is constructed of an inert bio-compatible material such as teflon, and includes porous membranes 166 and 168 on two of its sides, opposite to each other and adjacent to anode 152 and cathode 154 . Porous membranes 166 and 168 are designed to allow glucose and oxygen molecules to enter the interior of electrochemical cell 150 , and to exclude all other macromolecules. The configuration of two porous membranes provides for an improved flow of glucose and oxygen across the arrays of nanostructured rods 156 and 158 , compared to housing 114 of electrochemical cell 100 .
[0057] Continuing with FIGS. 2A and 2B , an electrodeposition process 200 for fabricating arrays of gold or titanium nanostructured rods 106 , 108 , 156 , and 158 will now be disclosed. As shown in FIGS. 2A and 2B , process 200 begins with a step 202 of evaporating or sputtering a ten nanometer thick seed layer 252 of gold on a silicon substrate 250 . Process 200 continues with a step 204 of evaporating or sputtering a two micron thick layer 254 of aluminum onto gold seed layer 252 .
[0058] After layer 254 of aluminum is evaporated or sputtered onto gold seed layer 252 , electrodeposition process 200 continues with steps 206 - 210 . In step 206 , a top surface 255 of aluminum layer 254 is electropolished with perchloric-ethanol and H 3 PO 4 -butanol to remove any surface defects. In step 208 , aluminum layer 254 is anodized using H 2 SO 4 , H 3 PO 4 , mixed H 2 SO 4 /H 3 PO 4 , and oxalic acid. Anodizing step 208 converts aluminum layer 254 to porous alumina, whereby approximately 1,600 pores are produced during step 208 . In step 210 , the pores of alumina layer 254 are widened to an average approximate diameter of 500 angstroms using 0.2 M of H 3 PO 4 which completes the anodizing process.
[0059] Continuing now with FIGS. 2A and 2B , electrodeposition process 200 continues with a step 212 of electrodepositing gold or titanium into the pores of alumina layer 254 . Process 200 continues with a step 214 of dissolving alumina layer 254 by chemical etching, leaving the approximately 1,600 gold or titanium nanostructured rods attached to silicon substrate 250 . As mentioned above, each nanostructured rod is approximately two microns in height and 500 angstroms in diameter.
[0060] Referring now to FIGS. 3A and 3B , a chemical vapor deposition process 300 for fabricating arrays of carbon nanotube rods 106 , 108 , 156 , and 158 will now be disclosed. As shown in FIGS. 3A and 3B , process 300 begins with a step 302 of evaporating or sputtering a ten nanometer thick seed layer 352 of gold on a silicon substrate 350 . Process 300 continues with a step 304 of evaporating or sputtering a two micron thick layer 354 of aluminum onto gold seed layer 352 .
[0061] After layer 354 of aluminum is evaporated or sputtered onto gold seed layer 352 , a chemical vapor deposition process 300 continues with steps 306 - 310 . In step 306 , a top surface 355 of aluminum layer 354 is electropolished with perchloricethanol and H 3 PO 4 -butanol to remove any surface defects. In step 308 , aluminum layer 354 is anodized using H 2 SO 4 , H 3 PO 4 , mixed H 2 SO 4 /H 3 PO 4 , and oxalic acid. Anodizing step 308 converts aluminum layer 354 to porous alumina, whereby approximately 1,600 pores are produced during step 308 . In step 310 , the pores of alumina layer 354 are widened to an average approximate diameter of 500 angstroms using 0.2 M of H 3 PO 4 which completes the anodizing process.
[0062] Continuing now with FIGS. 3A and 3B , chemical vapor deposition process 300 continues with a step 312 of a catalyst layer of iron (Fe), cobalt (Co), or nickel (Ni) into the pores of alumina layer 354 , followed by a step 314 of growing carbon nanotubes at 700° C. Process 300 continues with a step 316 of dissolving alumina later 354 by chemical etching, leaving the approximately 1,600 carbon nanotubes attached to silicon substrate 350 . As mentioned above, each carbon nanotube is approximately two microns in height and 500 angstroms in diameter.
[0063] Continuing with FIG. 4 , the steps of a first process 400 for forming and depositing immobilized enzyme layers 110 , 112 , 160 , and 162 on anodes 102 and 152 , and cathodes 104 and 154 , in accordance with the first, second, and third embodiments of the present invention, are now disclosed. Process 400 is based on a conventional Langmuir-Blodgett process (See: Langmuir-Blodgett Films, edited by G. Roberts, Plenum, New York, 1990) for depositing monolayer organic films on a solid substrate that provides: (1) precise control of the monolayer thickness; (2) homogeneous deposition of the monolayer over large areas; and (3) the ability to build multi-layer structures with varying layer composition. An additional advantage of the Langmuir-Blodgett technique is that monolayers can be deposited on almost any type of substrate.
[0064] The Langmuir-Blodgett technique uses the surface free energy and surface tension properties of a liquid at the gas/liquid interface. In the particular case of a polar liquid such as water, there are strong intermolecular interactions and thus high surface tension. Any factor which decreases the strength of these interactions, especially the presence of surface active agents (surfactants), will lower the surface tension of the liquid.
[0065] Surfactants are amphiphilic molecules that consist of a hydrophilic (water soluble) and a hydrophobic (water insoluble) part. The hydrophilic part usually consists of a polar group and the hydrophobic part consists of hydrocarbon or fluorocarbon chains. The hydrocarbon or fluorocarbon chain has to be long enough to form an insoluble monolayer; otherwise, the amphiphiles on the water surface tend to form water soluble micelles that prevent build up of a monolayer. However, if the chain is too long the amphiphile tends to crystallize on the water surface, which again prevents the build up of a monolayer. Fortunately, a wide range of amphiphiles exist which lower the surface tension of water, and the amphiphilic nature of the molecules dictates the orientation of the molecules at the air/water interface.
[0066] When a solution of an amphipile in a water soluble solvent is placed on a water surface, the solution spreads rapidly to cover the available area. As the solvent evaporates, a monolayer is formed on the surface of the water. When the available area for the monolayer is large, the distance between adjacent amphiphilic molecules is large and their interactions are weak. This is referred to as the “gas phase” and in this phase the monolayer has very little effect on the surface tension of the water.
[0067] However, if the available surface area of the monolayer is reduced by a barrier system, the amphiphilic molecules begin to exert a repulsive force on each other and the monolayer transitions from the gas to a “liquid phase.” If the area is reduced further, the monolayer will eventually transition from the liquid to a “solid phase” in which the Langmuir-Blodgett technique is carried out. In the solid phase, the surface pressure is sufficiently high to ensure that the attraction between the monolayer molecules is high enough so that the monolayer does not fall apart during transfer to the solid substrate. This also ensures the build up of homogeneous multi-layers.
[0068] Note that the phase behavior of a specific amphiphile is determined by its physical and chemical properties, including temperature, the length of the hydrocarbon chain, and the magnitude of other cohesive and repulsive forces existing between the polar groups.
[0069] Referring again to FIG. 4 , process 400 begins with a step 402 of depositing a solution containing one of immobile enzymes 110 , 112 (glucose oxidase) or 160 , 162 (laccase) on the surface of water contained in a teflon trough (not shown). The surface area of the water of controlled to maintain the monolayer in the solid phase by a pair of sweeping movable barriers (not shown) made of a hydrophilic material such as Delrin. Process 400 continues with a step 404 of successively dipping and withdrawing anodes 102 and 152 , and cathodes 104 and 154 up and down through the enzyme monolayer while simultaneously maintaining a constant surface pressure by a computer-controlled feedback system. Since gold, titanium and carbon are hydrophobic, the first enzyme monolayer is deposited by lowering the anode or cathode into the water through the monolayer. As shown in FIG. 4 , the first enzyme monolayer is adsorbed with the hydrocarbon chains toward the surface of anodes 102 and 152 , and cathodes 104 and 154 in the down direction. Subsequent layers are formed by deposits in both the up and down directions, and in this way multi-layered structures of immobile enzymes 110 , 112 , 160 , or 162 are produced.
[0070] FIGS. 5A-5C show the exemplary steps of a second process 500 for forming and depositing immobilized enzyme layers 110 , 112 , 160 , or 162 containing latex or other biocolloidal substrates and silica nanoparticles, on the surfaces and nanostructured rods of anodes 102 and 152 , and cathodes 104 and 154 . Process 500 begins with steps 502 - 528 of forming biocolloidal substrates containing silica nanoparticles and immobilized enzymes 110 , 112 (glucose oxidase) or 160 , 162 (laccase), using a modified layer-by-layer assembly process (See: M. Fang, P. Grant, M. McShane, G. Sukhorukov, V. Golub, Y. Lvov, Langmuir, 2002, v. 18, 6338-6344. “Magnetic Bio/Nanoreactor with Multilayer Shells of Glucose Oxidase and Inorganic Nanoparticles”). Steps 502 - 528 involve the stepwise growth of organized layers of oppositely charged polyelectrolytes, silica, and immobilized enzyme layers on biocolloidal substrates; for example, on latex spheres or carbon buckyballs, by alternately processing the substrates in polycation (positively charged) and polyanion (negatively charged) solutions. The inclusion of the silica layers yields a higher substrate surface area, resulting in greater enzyme adsorption and thereby increasing the catalytic activity of the immobilized enzyme. The deposition mechanisms in this process are electrostatic attraction, van der Waal forces, and capillary forces.
[0071] Continuing with FIG. 5A , steps 502 - 514 describing the formation of biocolloidal substrates containing organized layers of silica nanoparticles and glucose oxidase, are now described. Beginning with step 502 , a first polycationic solution is added to a suspension of biocolloidal substrates until adsorption saturation. Biocolloidal substrates may comprise latex spheres or carbon buckyballs. In step 504 , a polyanionic solution is added to the suspension of biocolloidal substrates until adsorption saturation. Steps 502 and 504 are performed twice. In step 506 , a second polycationic solution is added to the suspension of biocolloidal substrates until adsorption saturation. In step 508 , silica nanoparticles are added to the suspension of biocolloidal substrates until adsorption saturation. Steps 506 and 508 are performed one to four times. In step 510 , a third polycationic solution is added to the suspension of biocolloidal substrates until adsorption saturation. In step 512 , a polyanionic solution containing glucose oxidase is added to the suspension of biocolloidal substrates until adsorption saturation occurs. Steps 510 - 512 are performed once or twice. After each of steps 502 - 512 , in a step 514 the coated biocolloidal substrates are separated from the unabsorbed species by centrifugation and the supernatant containing the unabsorbed species is removed. At this stage, the biocolloidal substrates are coated with up to four layers of silica nanoparticles and one or two layers of immobilized glucose oxidase with the following shell architectures:
{PEI/PSS} 2 +{PEI/silica} 0-4 +{PEI/GO x } 1-2 .
where PEI is polyethyleneimine, PSS is polystyrenesulfonate.
[0072] Referring to FIG. 5B , steps 516 - 528 are now used to describe the formation of biocolloidal substrates containing organized layers of silica nanoparticles and laccase. In this case, the differences are the reversals of the polycationic and polyanionic solutions, and the substitution of laccase in place of glucose oxidase.
[0073] Beginning with step 516 , a first polyanionic solution is added to a suspension of biocolloidal substrates until adsorption saturation. In step 518 , a polycationic solution is added to the suspension of biocolloidal substrates until adsorption saturation. Steps 516 and 518 are performed twice. In step 520 , a second polyanionic solution is added to the suspension of biocolloidal substrates until adsorption saturation. In step 522 , silica nanoparticles are added to the suspension of biocolloidal substrates until adsorption saturation. Steps 520 and 522 are performed one to four times. In a step 524 , a third polyanionic solution is added to the suspension of biocolloidal substrates until adsorption saturation. In step 526 , a polycationic solution containing laccase is added to the suspension of biocolloidal substrates until adsorption saturation occurs. Steps 524 and 526 are performed one or two times. After each of steps 516 - 526 , in a step 528 the biocolloidal substrates are separated from the unabsorbed species by centrifugation and the supernatant containing the unabsorbed species is removed. At this stage, the biocolloidal substrates are coated with up to four layers of silica nanoparticles and one or two layers of immobilized laccase with the following shell architectures:
{PSS/PEI} 2 +{PSS/silica} 0-4 +{PSS/laccase} 12 .
[0074] Referring now to FIG. 5C , process 500 continues with a step 530 of depositing a solution, containing the biocolloidal substrates coated with silica nanoparticles and one of immobile enzymes 110 , 112 or 160 , 162 , on the surface of water contained in a teflon trough (not shown). The surface area of the water of controlled to maintain the monolayer in the solid phase by a pair of sweeping movable barriers (not shown) made of a hydrophilic material such as Delrin. Process 500 continues with a step 532 of successively dipping and withdrawing anodes 102 and 152 , and cathodes 104 and 154 up and down through the biocolloidal substrate monolayer while simultaneously maintaining a constant surface pressure by a computer-controlled feedback system. As discussed in connection with FIG. 4 and process 400 , since gold, titanium and carbon are hydrophobic, the first biocolloidal substrate monolayer is deposited by lowering the anode or cathode into the water through the monolayer.
[0075] Referring now to FIG. 6 , the glucose oxidation and oxygen reduction reactions of electrochemical cells 100 and 150 of the present invention, are now disclosed. A unit cell of this bio-fuel cell consists of two compartments 602 and 604 . Individual compartment is made up of a porous membrane top layer 606 , bio-compatible material coated side-walls 608 , and a nanowire-based bottom layer 610 on a heavily-doped silicon substrate 612 . A heavily-doped silicon substrate also has a number of pores 614 with a few hundred nanometer-size diameter. The nanowire-based cathode electrodes 616 and anode electrodes 618 are coated with glucose oxidase (GOx) enzymes 620 and laccase enzymes 622 , respectively. Individual substrate 612 and 624 plays a role of conducting paths for electrons from nanowire-based cathodes 616 and anodes 610 to outside world 626 and 628 , respectively. The back-side of substrates containing nanowire-based cathode 616 and anode 610 compartments are bonded together having an insulator layer 630 in between so glucose is diffused into the cell from both the top-porous membrane and the bottom-porous membrane. GOx-catalyzed oxidation of glucose at the anode is coupled with laccase-catalyzed oxygen reduction at the cathode in a miniature, non-compartmentalized system.
[0076] In electrochemical cells 100 and 150 , glucose is oxidized by glucose oxidase (GO x ) in a half-reaction at anode 610 or 152 , respectively. Simultaneously, oxygen is reduced by laccase in a half-reaction at cathode 616 or 154 , respectively. The following are the combined half-reactions:
Glucose→gluconolactone+2H + +2e − : cathode O 2 +4H + +4e − →2H 2 O: anode
[0077] More specifically, glucose oxidase catalyzes the oxidation of each molecule of β-D-glucose to D-gluconic acid and hydrogen peroxide. Since glucose oxidase is highly specific for β-D-glucose, it does not act on α-D-glucose; however, as a result of the consumption of β-D-glucose, α-D-glucose is converted into the β-form by mutarotation. The two electrons that are released by each glucose molecule from the nanowire-based cathode generating gluconolactone are used to perform electrical work through an external circuit.
[0078] Once the two electrons released by glucose oxidation with each glucose molecule have performed electrical work, laccase catalyzes the reduction of an oxygen molecule, four hydrogen nuclei and four electrons to form two water molecules. Laccase is a copper-containing phenyloxidase that requires a pH of 5.0 for optimal activity and stability; however, the pH of the human body is normally 7.2-7.4 so an effective system that operates at neutral pH is needed. This is accomplished in the present invention by using a pyrroloquinoline quinone (PQQ) mediated glucose oxidase system with tree-derived laccase.
[0079] A related issue is eliminating the need for membrane-separated anode and cathode compartments. In the present invention, this need is eliminated through effective coupling of the immobilized enzymes to the anode and cathode, so that very little glucose reacts at the cathode, and very little oxygen reacts at the anode.
[0080] Continuing with FIGS. 7 and 8 , functional schematics of three electrochemical cells connected in series 700 to provide an increase output voltage, and six electrochemical cells connected in series-parallel 800 , are disclosed. As exemplified in FIG. 7 , any number of cells may be connected in series to generate sufficient voltage to power active implanted medical devices. Similarly, as exemplified in FIG. 8 , any number of cells may be connected in series-parallel to provide for the generation of sufficient voltage and current to power any type of active implantable medical device.
[0081] Referring now to FIG. 9 , a functional schematic of an integrated implantable medical device 900 will now be discussed. Device 900 is an example of the type of single-chip, programmable devices that are possible using the electrochemical cell of the present invention, and may comprise a substrate 902 on which are fabricated a power source 904 , a sensor array 906 , a CPU/control module 908 , a stimulation array 910 , and a communication module 912 .
[0082] For example, in one embodiment, device 900 may be programmed to function as a rate-adaptive cardiac pacemaker, in which sensor array 906 is configured to measure one or more parameters related to the physiologically correct value of the cardiac stimulation frequency. Such measured parameters may, for example, relate respiration with circulation activity to determine the physiologically correct stimulation frequency. CPU/control module 908 is programmed to establish the physiologically correct rate of the stimulation pulses, depending on the measured physiological parameters. Stimulation array 910 is then configured to generate stimulation pulses to the heart. Communication module 912 is configured to store and output calibration and control parameters to a receiver located external to the body.
[0083] Because device 900 includes electrochemical power source 904 and communication module 912 integrated on a common substrate 902 , the device may be much smaller than existing implantable devices. In addition, since power source 904 does not require recharging, device 900 may be implanted essentially permanently.
[0084] The foregoing description includes what are at present considered to be preferred embodiments of the present invention. However, it will be readily apparent to those skilled in the art that various changes and modifications may be made to the embodiments without departing from the spirit and scope of the invention. For example, the exact dimensions of the electrochemical cell, the nanowires, or the carbon nanotubes may be changed. Alternatively, the precise dimensions, quantity, and composition of the biocolloidal substrates that are affixed to the anode and cathode may vary. Accordingly, it is intended that such changes and modifications fall within the spirit and scope of the invention, and that the present invention be limited only by the following claims.
|
A bio-implantable electrochemical cell system for active implantable medical devices. In one embodiment, the fuel cell includes an electrode structure consisting of immobilized anode and cathode enzymes deposited on nanostructured high-surface-area metal nanowires or carbon nanotube electrodes. The anode enzyme comprises immobilized glucose oxidase and the cathode enzyme comprises immobilized laccase. Glucose is oxidized at the surface of the anode and oxygen is reduced at the surface of the cathode. The coupled glucose oxidation-oxygen reduction reactions provide a self-generating current source. In another embodiment, the nanowires or carbon nanotubes, along with the adjacent surface anode and cathode electrodes, are coated with immobilized glucose oxidase and immobilized laccase containing biocolloidal substrates, respectively. This results in the precise construction of an enzyme architecture with control at the molecular level, while increasing the reactive surface area and corresponding output power by at least two orders of magnitude.
| 7
|
FIELD OF THE INVENTION
The present invention relates to the field of preventing or reducing incidence or severity of an allergic immune response, and compositions for preventing or reducing incidence or severity of an allergic immune response.
BACKGROUND TO THE INVENTION
Allergic reactions are generally immune reactions that are initiated by IgE-dependent stimulation of tissue mast cells and related effector molecules (e.g., basophils). Binding events between cell surface bound IgE molecules and antigen results in rapid release of biological response modifiers which bring about increased vascular permeability, vasodilation, smooth muscle contraction and local inflammation. This sequence of events is termed immediate hypersensitivity and begins rapidly, usually within minutes of exposure in a sensitised individual. In its most severe systemic form, anaphylaxis, such immediate hypersensitivity can bring about asphyxiation, produce cardiovascular collapse, and even result in death. Individuals that are prone to strong immediate hypersensitivity responses are referred to as “atopic”. Clinical manifestations of allergy or atopy include hay fever (rhinitis), asthma, urticaria (hives), skin irritation (e.g., eczema such as chronic eczema), anaphylaxis, and related conditions.
The prevalence of atopy has increased in the developed world since the beginning of the 20 th century when allergy prevalence was estimated to be less than 0.1% in Europe, UK and US (Schadewaldt H, 1980, Geschichte der Allergies in vier Dustri-Verlag; as cited by Matthias Wjst, 2009 , Allergy, Asthma & Clinical Immunology. 5:8). About 30-40% of the world population is now affected by one or more allergic conditions. Asthma, rhinitis, and eczema are now prevalent in developed countries, with allergic disorders being the most common chronic diseases among children in developed countries. For example, more than 25% of infants in Australia today present with eczema, more than 20% of one-year olds are food-sensitised, more than 25% of children have asthma, and more than 40% of adults have a history of allergic rhinitis (Pawnkar R, Walter Canonica G, Holgate S T, Lockey R F, 2001, World Allergy Organization (WAO) White Book on Allergy). Allergies also affect about 20% of all individuals in the United States. Atopy is predicted to increase to about 26 of the Australian population by 2050.
Although childhood asthma often improves during childhood, asthma and rhinitis persist throughout adulthood, with substantial increase in asthma associated mortality for those aged more than 60 years (Martin P E et al., 2011 , J. Allergy Clin. Immunol. 127:1473-1479).
There is a significant economic burden associated with allergic conditions. For example, in 2007 the associated economic cost in Australia was estimated to be $9.4 billion with an additional $21.3 billion from lost wellbeing (e.g., disability and premature death). In the UK, the total annual expenditure for atopic eczema has been estimated at £465 million ( 521 m). In Germany, the total average costs for an atopic eczema patient have been estimated to be about 4400. In the US, the direct and indirect costs of asthma to the US economy were projected to have reached US$20.7 billion in 2010, and the direct cost of treating childhood asthma alone exceeds US$1,100 per patient per annum. The cost of treating incidence of eczema alone in patients aged 0 to 5 years is approximately US$360 per patient per annum with an annual cost of over $400,000 in Australia, 5 million in Western Europe and US$3 million in the US.
Several studies have documented temporal changes in allergy patterns in developed countries, from a prevalence of allergic asthma and hay fever in children (Mullins R J, 2007 , Med J Aust. 186: 618-621) toward increasing eczema and food allergies during the last 10 years. In this second wave of the allergy epidemic, 10% of children have some form of food allergy (Osborne N J et al., 2011 , J. Clin. Immunol. 127:668-676; Prescott S and Allen K J, 2011 , Pediatr. Allergy Immunol. 22:155-160). This changing epidemiology for allergic disorders remains largely unexplained.
As illustrated in panel (A) of FIG. 1 hereof, infants who have moderate to severe eczema are at higher risk of developing food allergies and/or allergic asthma later in life e.g., during childhood, and a significant proportion of these individuals will have atopic or respiratory allergies as adults. This is the so-called “atopic march” or “allergic march” (Martin P E et al., 2011 , J. Allergy Clin. Immunol. 127:1473-1479). The current generation with food allergies appear to present with symptoms earlier in life than previous generations having respiratory allergies, and appear less likely to outgrow their allergy during early adulthood (Prescott S and Allen K J, 2011 , Pediatr. Allergy Immunol. 22:155-160).
The so-called “hygiene hypothesis” attributes the increase in atopy in developed countries to an increase in the use of antibiotics to treat microbial infections in infancy and/or childhood (Strachan D P, 1989 , BMJ, 299:1259-1260; Strachan D P, Harkins L S, Golding J, 1997 , Clin. Exp. Allergy. 27:151-155; Renz H and Herz U, 2002 , Eur. Respir. J. 19:158-171). According to the hygiene hypothesis, changes in the biodiversity of the microbial environment, human microbiome, and reduced exposure to microbes that regulate the host immune system cause childhood allergy leading to the atopic march e.g., because antibiotics reduce the incidence of microorganisms that are beneficial for a balanced immune system development in addition to reducing the incidence of pathogens (Guarner F et al., 2006 , Nat. clin. Pract. Gastroenterol. Hepatol. 3: 275-284).
Selection of an appropriate T-cell population occurs during the early stages of immune responses in naive unsensitised hosts such as neonates and new borns and infants having an undeveloped immune system. If selection favours priming the host immune system toward the induction of allergen-specific TH1 cells, then IgG and IgA responses may ensue. TH1 cells seem to play a role in defense against various microbial antigens including bacterial, viral and fungal infections, and uncontrolled TH1 responses are involved in organ-specific autoimmunity e.g., in rheumatoid arthritis, multiple sclerosis, thyroiditis, Crohn's disease, systemic lupus erythematosus, experimental autoimmune uveoretinitis (Dubey et al., 1991 , Eur. Cytokine Network, 2:147-152), experimental autoimmune encephalitis (EAE) (Beraud et al., 1991 , Cell Immunol. 133:379-389), insulin-dependent diabetes mellitus (Hahn et al., 1987 , Eur. J Immunol. 18:2037-2042), contact dermatitis (Kapsenberg et al., Immunol Today, 12:392-395), and in some chronic inflammatory disorders. The principal inflammatory cytokine produced by TH1 cells is IFN-γ (See, for example, Romragnani, ed, TH1 and TH2 Cells in Health and Disease. Chem. Immunol., Karger, Basel, 63, pp. 158-170 and 187-203 (1996)).
On the other hand, the emergence of TH2 cells can lead to IgE production and eosinophilia and ultimately atopic disease. See e.g., WO2005/030249. Allergy, asthma, eczema, psoriasis, allergic rhinitis, hay fever and atopic dermatitis are each associated with a profound immunological deregulation characterized by over production of TH2 cells (Romragnani, supra; van der Heijden et al., 1991 ; J Invest Derm. 97:389-394; Walker et al., 1992 , Am. Rev. Resp. Dis. 148:109-115; and Renz H and Herz U, 2002, supra), and uncontrolled TH2 type responses are responsible for triggering allergic disorders against environmental allergens and chemical allergens. TH2 type responses are also preferentially induced in certain primary immune deficiencies such as hyper-IgE syndrome (Del Prete et al., 1989 , J. Clin. Invest. 84:1830-1835) and Omenn's syndrome (Schandene et al., 1993 , Eur. J. Immunol. 23:56-60).
TH2 effector functions may be negatively regulated by TH1 cells. The hygiene hypothesis suggests that a reduced frequency of microbial infections, less severe infection, and prevention of infection e.g., by frequent use of antibiotics may prevent maturation of TH1 immunity, and give rise to allergen-specific TH-2 immune responses following subsequent exposure to allergens (Renz H and Herz U, 2002, supra).
There is currently no cure, and only limited treatment, for severe atopy. Treatment options are generally restricted to use of steroids, anti-histamines, immune modulation drugs and administration of adrenalin. At best these treatment regimens provide temporary relief and are generally not suitable for sustained use. Accordingly, there remains an unmet need in the art for compositions and methods for prevention of allergic disorders.
H. pylori is a gastric bacterial pathogen that chronically infects more than half of the world's human population. Infection with H. pylori is usually acquired early in childhood and, if left untreated, can last for a life time with the majority of infected individuals remaining asymptomatic. On the other hand, H. pylori infection is the main cause of peptic ulcer disease, which is manifested in more than 10% of infected subjects (Kuipers et al., 1995 . Aliment Pharmacol Ther, 9 Suppl 2: 59-69). H. pylori infection is also associated with an increased risk of non-cardiac gastric adenocarcinoma which is one of the most frequently lethal malignancies, and with gastric mucosa-associated lymphoid tissue (MALT) lymphoma (Suerbaum & Michetti, 2002 , N Engl J Med, 347: 1175-1186; Atherton (2006), Annu Rev Pathol. 1:63-96), as well as chronic urticaria (hives).
Epidemiological population studies suggest that prevalence of live H. pylori in the gastric mucosa is inversely-proportional to the incidence of allergy in developed countries. See e.g., Zevit et al., (2011), Helicobacter, 17: 30-35; Shiotani et al., (2008), BMJ, 320: 412-7; Chen & Blaser (2007), Arch Intern Med, 167: 281-7; McCune et al., (2003), Eur J Gastroenterol Hepatol, 15: 637-40; Reibman et al., (2008), PLoS ONE, 3: e4060; Konturek et al., (2008), Med Sci Monit, 14:CR453-8. However, a number of other studies have suggested that the correlation between falling H. pylori infection rates and raising allergy rates might not be correct. See, e.g., Zevit et al., (2011) supra; Raj et al. (2009), J Infect Dis, 199:914-5. These conflicting reports suggest uncertainty as to whether or not reduced colonization of the gastric mucosa by H. pylori is directly involved in the atopic march.
SUMMARY OF THE INVENTION
1. General
In work leading to the present invention, the inventors sought to identify and/or prepare composition(s) for improving tolerance of the immune system of a mammalian subject to allergy e.g., by preventing or delaying the development of atopy or the atopic march in a subject. In particular, the inventors sought to identify and/or prepare composition(s) capable of preventing or reducing severity or incidence of allergic immune response(s) to an allergen in a mammalian subject, or capable of preventing or attenuating severity of allergic disease such as airway hyper-responsiveness in a mammalian subject following exposure of the subject to an allergen. The inventors also sought to identify and/or prepare composition(s) capable of preventing or interrupting or limiting the atopic march and progression of an allergic disease such as eczema in children e.g., neonates and juveniles to food allergy and/or severe asthma later in life for example during adolescence and/or adulthood.
The inventors reasoned that an optimally-balanced immune system develops in the early post-natal period and, as a consequence, administration of a medicament to prevent the atopic march in a subject and development of allergy in adolescents and adults is optimally deliverable to neonates or during early childhood.
As exemplified herein, the present inventors have shown that an oral composition comprising inactivated and/or killed H. pylori administered to neonates or adults in a murine model of allergy reduced the incidence or severity of an allergic response to antigenic challenge e.g., as determined by measurement of airway or lung resistance. Thus, administration of an inactivated and/or killed H. pylori e.g., wherein the inactivated H pylori does not have the same capacity of a live H. pylori to colonize the mucosa of a mammal to which it is administered or wherein the inactivated or killed H. pylori is incapable of colonizing the mucosa of a mammal to which it is administered, or a H. pylori cell lysate, appears to interrupt or slow or arrest or prevent atopic march or further atopic march in the subject e.g., by delaying or preventing or interrupting or slowing the onset of one or more allergic conditions such as allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, or airway hyper-responsiveness or hyper-reactivity, food allergy, asthma etc.
The present invention therefore provides for a general reduction in hyper-responsiveness of an individual to one or more allergens thereby delaying or preventing or interrupting or slowing the onset of one or more allergic conditions. The reduced hypersensitivity may be demonstrated by reduced sensitivity of a subject to a specific allergen e.g., an accepted model allergen of hypersensitivity e.g., ovalbumin and/or ragweed administered as a challenge to murine animals e.g., BALB/c or C57/BL/6 or SJL/J mice, in an aerosolized form or by gavage. See e.g., Renz et al., J. Allergy Clin. Immunol. 89:1127-1138 (1992); Renz et al., J. Immunol. 151:1907-1917 (1993); Saloga et al., J. Clin. Invest. 91:133-140 (1993); Larsen et al., J. Clin. Invest. 89:747-752 (1992); Oshiba et al., J. Clin, Invest. 97: 1938-1408 (1996).
For example, by administering inactivated and/or killed H. pylori e.g., isolated inactivated and/or killed H. pylori , to a subject that is asymptomatic for eczema, or asymptomatic for allergy e.g., characterized by rhinitis or wheezing or airway resistance or restriction or airway hyper-responsiveness, or asymptomatic for asthma, a subsequent onset of eczema and/or allergy and/or asthma may be prevented. In one specific example, inactivated and/or killed H. pylori is administered to a juvenile subject such as a neonate or infant to prevent eczema in the infant or a subsequent onset of allergy or asthma in later life e.g., in adolescence or adulthood. In another example, inactivated and/or or killed H. pylori e.g., isolated inactivated and/or killed H. pylori , is administered to an adolescent or adult subject to prevent eczema in the subject or a subsequent onset of allergy or asthma, such as in later life. This is in a background in which allergic eczema, allergy or asthma is inducible at any stage of life by exposure of a subject to one or more challenge allergens, including one or more environmental allergens e.g., pollen allergen, dust mite allergen, animal allergen, chemical allergen etc.
Alternatively, by administering inactivated and/or killed H. pylori e.g., isolated inactivated and/or killed H. pylori , to a subject that has suffered previously from one or more incidences of allergic eczema, allergy e.g., characterized by rhinitis or wheezing or airway resistance or restriction, or asthma, a subsequent attack may be prevented or the severity of a subsequent attack may be reduced. In one specific example, inactivated and/or killed H. pylori e.g., isolated inactivated and/or killed H. pylori is administered to a juvenile subject that has suffered from allergic eczema to prevent a subsequent attack or reduce severity of a subsequent attack, optionally to prevent or slow further atopic march in the subject. In another example, inactivated and/or killed H. pylori e.g., isolated inactivated and/or killed H. pylori is administered to an adolescent or adult subject that has suffered previously from allergic eczema and/or allergy and/or asthma, to prevent a subsequent attack or reduce severity of a subsequent attack, optionally to prevent or slow further atopic march in the subject.
In an epidemiological context, the administration of inactivated and/or killed H. pylori e.g., isolated inactivated and/or killed H. pylori to a subject reduces the incidence of allergic immune responses in the population, and especially reduces the incidence of allergic immune responses in adolescent and/or adult members of the population treated when they were juveniles.
The demonstration that inactivated and/or killed H. pylori bacteria protect subjects in a mouse model of allergic airway disease provides the significant advantage of avoiding health risks associated with the use of live H. pylori cells, such as induction of peptic ulcers and/or gastric cancer. In other words, inactivated and/or killed H. pylori or a lysate of H. pylori offers a safe and controlled approach for positively-influencing the developing immune system, and preventing or reducing an allergic response to an allergen. Similarly, inactivated and/or killed H. pylori or a lysate of H. pylori offers a safe and controlled approach to delaying or preventing the atopic march by targeting events in early in life e.g., in children such as neonates and/or juveniles.
The present invention thus provides for administration, for example repeated administration, of inactivated and/or killed H. pylori bacteria and/or a lysate thereof e.g., to children or infants such as at 0 to 5 years of age, to thereby promote balanced immune development for reducing the severity or incidence of allergy e.g., as allergic eczema and/or a life-long food allergy and/or allergic asthma. The inactivated and/or killed H. pylori bacteria and/or a lysate thereof is also useful for modulating the immune system of a mammalian subject and/or for improving the immune system's tolerance to allergy.
As disclosed herein, the inactivated and/or killed H. pylori bacteria and/or a lysate thereof are formulated and/or used as a food ingredient or a food product such as medical food e.g., diary or non-dairy and/or dietary supplement(s) and/or as tablet(s) and/or as capsules. Such formulations are preferably mucosal compositions for improving immune system's tolerance to allergens and/or preventing or reducing allergy symptoms for example in adults and/or adolescents. The formulations are preferably for repeated administration, e.g., daily, to children and/or infants, e.g., aged 0 to 5 years, suffering from eczema and/or food allergy or susceptible to development of eczema or food allergy. In this respect, a subject may be susceptible to development of allergy at 0-5 years or 0-4 years or 0-3 year or 0-2 years or 0.5-5 years or 0.5-4 years or 0.5-3 years or 0.5-2 years or 0.5-1 years or 1-2 years or 1-3 years or 1-4 years or 1-5 years or 2-3 years or 2-4 years or 2-5 years or 3-4 years or 3-5 years of age. For example, to prevent or limit the atopic march in a subject, such as progression to food allergy and/or allergic asthma later in life, the subject is administered a plurality of doses of a formulation comprising the inactivated H. pylori or cell extract or lysate thereof, wherein the first does is administered at a time infra where the subject is susceptible to development of allergy. For example, the subject may be taking antibiotic therapy or prescribed antibiotic therapy, especially in the case of an infant or child that is susceptible to development of allergy.
Without being bound by theory or specific mode of action, the inventors postulated that the inactivated and/or killed H. pylori of the present invention retain and/or form a cell structure scaffold and/or a conglomerate or aggregate of cell structure scaffold. Without being bound by theory or specific mode of action, the inventors also postulated that this scaffold and/or conglomerate or aggregate may be important for facilitating immune modulation in a subject towards a balanced immune response to an allergen e.g., balanced Th1/Th2 immune response in a subject and/or to interrupt or slow or arrest or prevent atopic march or further atopic march in the subject e.g., by delaying or preventing or interrupting or slowing the onset of one or more allergic conditions described herein.
SPECIFIC EXAMPLES OF THE INVENTION
The scope of the invention will be apparent from the claims as filed with the application that follow the examples. The claims as filed with the application are hereby incorporated into the description. The scope of the invention will also be apparent from the following description of specific embodiments and/or detailed description of preferred embodiments.
Accordingly, in one example, the invention provides a composition comprising an H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is inactivated e.g., by virtue of having reduced capacity to colonize the mucosa of a mammal relative to a live H. pylori cell such as a live H. pylori cell having the same genotype as the inactivated cell, or by virtue of being incapable of colonizing the mucosa of said mammal, and preferably wherein the H. pylori is killed e.g., by heat treatment.
In some embodiments, the composition of the present invention consists essentially of an H. pylori cell and/or a cell lysate thereof together with a pharmaceutically acceptable carrier, wherein said H. pylori cell is inactivated e.g., by virtue of having reduced capacity to colonize the mucosa of a mammal relative to a live H. pylori cell for example having the same genotype as the inactivated cell, or by virtue of being incapable of colonizing the mucosa of said mammal, and preferably wherein the H. pylori is killed e.g., by heat treatment.
It will be appreciated by those skilled in the art that any H. pylori strain is used; however, in some examples the H. pylori strain is cagA minus (cagA − ). In some examples, the H. pylori strain is cagA − and is also positive for the toxigenic s1 and m1 alleles of the vacA gene.
In some examples, the present invention provides strains of H. pylori having the characteristics of a strain selected from the group consisting of OND737, as deposited in the National Measurement Institute under Accession No. V09/009101; OND738, as deposited in the National Measurement Institute under Accession No. V09/009102; OND739, as deposited in the National Measurement Institute under Accession No. V09/009103; OND248, as deposited in the National Measurement Institute under Accession No. V10/014059; OND256 as deposited in the National Measurement Institute under Accession No. V10/014060; OND740, as deposited in the National Measurement Institute under Accession No. V09/009104; OND79, as deposited in the National Measurement Institute under Accession No. V13/023374, and/or OND86, as deposited in the National Measurement Institute under Accession No. V14/013016, or a passaged strain, a mutant or a derivative thereof.
In some examples, the H. pylori strain of the present invention has been passaged through an animal host such as a human host. For example, the H. pylori strain of the present invention is derived from the H. pylori strain OND79 after passage of the OND79 strain in a human subject e.g., following infection and/or colonization of the gastric mucosa of a human subject with H. pylori OND79 strain. In one such example, the H. pylori strain of the present invention is OND86.
While the H. pylori strain used in the present invention is typically a non-genetically modified bacterium, in some examples the H. pylori strain is genetically modified to comprise one or more nucleic acid molecule(s) encoding at least one heterologous antigen or a functional fragment thereof.
In some examples the nucleic acid molecule resides extra-chromosomally on, for example, a plasmid vector such as a shuttle vector. Preferably, the plasmid vector would comprise (a) a nucleic acid sequence encoding the heterologous antigen and (b) a control or regulatory sequence operatively linked thereto which is capable of controlling the expression of the nucleic acid when the vector is transformed into a H. pylori strain. In other examples, the nucleic acid molecule inserts into the H. pylori chromosome upon transformation into the H. pylori.
Suitable antigens will be known to the person skilled in the art. Preferably the antigen is an environmental antigen, and may be used either singly or as a combination of two or more such antigens.
In some examples, the composition of the present invention will comprise an adjuvant. The adjuvant may be any adjuvant known in the art; however, preferably, the adjuvant is selected from the group consisting of alum, petiussis toxin, lacto fucopentaose III, phosphopolymer, complete Freund's adjuvant, monophosphoryl lipid A, 3-de-O-acylated monophosphoryl lipid A (3D-MPL), aluminium salt, CpG-containing oligonucleotides, immunostimulatory DNA sequences, saponin, MONTANIDE® 1SA 720, SAF, ISCOM.S, MF-59®, SBAS-3, SBAS-4, Detox, RC-529, aminoalkyl glucosaminide 4-phosphate, and LbeiF4A or combinations thereof. Alternatively, in other examples, the mucosal composition of the present invention does not comprise an adjuvant and/or is administered in the absence of an adjuvant.
The invention is useful in preventing and/or treating allergy in a mammal at risk of developing an allergy or having an allergy. In some examples, the allergy is selected from the group consisting of contact dermatitis, chronic inflammatory disorders, allergic atopic disorders, allergic asthma, atopic dermatitis, hyper-IgE syndrome, Omenn's syndrome, psoriasis, hay fever, allergic rhinitis, urticaria, eczema and food allergies.
Accordingly, in a further example the present invention provides a composition for use in preventing or treating allergy in a mammal comprising an H. pylori cell such as an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal. Optionally, the cell lysate is a whole cell lysate (WCL) of the inactivated H. pylori cell.
In a further example, the present invention provides a composition comprising an H. pylori cell such as an isolated H. pylori cell, or a cell lysate thereof or combination thereof and a pharmaceutically acceptable carrier, wherein said H. pylori cell is inactivated e.g., by virtue of having reduced capacity to colonize the mucosa of a mammal relative to a live H. pylori cell for example having the same genotype as the inactivated cell or by virtue of being incapable of colonizing the mucosa of a mammal. Preferably, the composition is for mucosal delivery. Optionally, the cell lysate is a whole cell lysate (WCL) of the inactivated H. pylori cell.
In another example, the present invention provides a composition comprising inactivated and/or killed H. pylori cells, such as isolated inactivated and/or killed H. pylori cells, or a cell lysate thereof, wherein said composition is formulated to be administered mucosally to a subject for interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in the subject. For example, the cell lysate is a WCL. In one such example, interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in the subject comprises delaying or preventing or interrupting or slowing the onset of one or more allergic conditions in the subject.
For example, an allergic condition may comprise allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma. Preferably, an allergic condition comprises airway resistance or airway hyperresponsiveness or hyperreactivity in response to an allergen and wherein the composition is for reducing said airway resistance. Alternatively, or in addition, an allergic condition comprises lung inflammation in response to an allergen and wherein the composition is for reducing said lung inflammation e.g., as characterized by a reduced level of cell infiltrate in lung. Alternatively, or in addition, an allergic condition is characterized by an elevated serum level of allergen-specific IgE antibody and/or an elevated level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or an elevated level of cell infiltrate in lung. For example, the composition reduces a serum level of allergen-specific IgE antibody and/or a level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or a level of cell infiltrate in lung relative to a level thereof in a subject exposed to an allergen and not administered said composition. Alternatively, the composition prevents or delays an increase in a serum level of allergen-specific IgE antibody and/or prevents or delays an increase in a level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or prevents or delays an increase in a level of cell infiltrate in lung in a subject exposed to an allergen.
Preferably, the composition as described according to any example hereof comprises H pylori cells or strains which have reduced capability in colonizing the mucosa of a subject relative to live H pylori cells or strains or are incapable of colonizing the mucosa of a subject. Alternatively, or in addition, the composition according to any example described hereof comprises H pylori cells or strains which are inactivated e.g., by irradiation such as gamma irradiation and/or ultraviolet irradiation and/or heat treatment and/or chemical means and/or by exposure to acid and/or by exposure to a base and/or by physical means such as pressure and/or by lyophilisation and/or by freeze-thawing. Alternatively, or in addition, the composition according to any example hereof comprises H. pylori cells or strains which are killed e.g., by heat treatment such that the cells are rendered irreversibly metabolically inactive. In another example, the composition according to any example hereof comprises H pylori cells or strains that have been subjected to a process for inactivating H. pylori cells and a process for killing the H. pylori cells. In one particular example, the inactivated H. pylori cells or strains described according to any example hereof are killed.
Alternatively, or in addition, the composition described according to any example hereof comprises a lysate e.g., WCL of H. pylori cells wherein the cells have been subjected to a process for inactivating H. pylori cells and/or a process for killing the H. pylori cells.
For example, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to irradiation such as gamma irradiation and/or ultraviolet irradiation and/or by exposure to visible light such as wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm e.g., 405 nm violet light. In one example, inactivated H. pylori as described according to any example hereof is prepared by a process comprising exposing live H. pylori cells or strains to ultraviolet C (UVC) irradiation such as wavelength in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or to ultraviolet B (UVB) irradiation such as wavelength in a range from about 280 nm to about 315 nm and/or to ultraviolet A (UVA) irradiation such as wavelength in a range from about 315 nm to about 400 nm. Preferably, the live H. pylori is exposed to UVC light in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or the live H. pylori is exposed to about 405 nm violet light.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to one or more chemical agents such as formaldehyde and/or β-propiolactone and/or ethyleneimine and/or binary ethyleneimine and/or thimerosal and/or polyethyleneimine functionalized zinc oxide nanoparticles, or derivatives thereof. For example, live H. pylori cells or strains may be inactivated by exposure to formaldehyde at a concentration from about 0.01% to about 1% (w/w) or from about 0.01% to about 0.1% (w/w) or between about 0.025% and about 0.1% (w/w).
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to heat treatment such as at temperatures in the range between about 40° C. to about 70° C. or more. Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to one or more acid(s) or to a low pH environment such as pH 3.0 or lower and/or to one or more base(s) or to high pH environment such as pH 9.0 or higher.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to one or more reducing agent(s) such as sodium bisulfite and/or one or more oxidative agents such as hydrogen peroxide.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to bile salts.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by mutagenesis of live H pylori cells or strains.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by lyophilizing or freeze-drying live H. pylori cells or strains. Alternatively, or in addition, inactivated H pylori as described according to any example hereof is prepared by performing one or cycles of freezing and thawing live H. pylori cells or strains.
For example, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to heat treatment such as by exposure to temperature of about 60° C. or more for at least about 60 seconds, preferably at a temperature of about 60° C. or about 70° C. or about 80° C. or about 90° C. or about 100° C. or about 110° C. or about 120° C. or about 130° C. or about 140° C. or about 150° C., said temperature exposure being for a period of at least 2 minutes or at least 3 minutes or at least 4 minutes or at least 5 minutes or at least 6 minutes or at least 7 minutes or at least 8 minutes or at least 9 minutes or at least 10 minutes or at least 20 minutes or at least 30 minutes or at least 40 minutes or at least 50 minutes or at least 1 hour or at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours or at least 7 hours or at least 8 hours or at least 9 hours or at least 10 hours or at least 11 hours or at least 12 hours or at least 13 hours or at least 14 hours or at least 15 hours or at least 16 hours or at least 17 hours or at least 18 hours or at least 19 hours or at least 20 hours or at least 21 hours or at least 22 hours or at least 23 hours or at least 1 day or at least 2 days or at least 3 days or at least 5 days or at least 5 days or at least 6 days or at least 7 days. In one preferred example, live and/or inactivated H. pylori is killed by exposure to a single such elevated temperature or by exposure to at least two different elevated temperatures such as by exposure to a first temperature of about 70° C. followed exposure to a second temperature of about 90° C. or about 95° C. In one such preferred example, the live and/or inactivated H pylori is killed by exposure to temperature of about 70° C. for about 10 minutes followed by exposure to temperature of about 90° C. or about 95° C. for about 5 minutes.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to elevated temperatures in the presence of steam and elevated pressure, such as by autoclaving live and/or inactivated H. pylori cells or strains. For example, live and/or inactivated H. pylori is killed by autoclaving the bacterial cells or strains for about 15 minutes at about 121° C. and about 15 psi, or for about 3 minutes at about at 132° C. and about 30 psi.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to one or more bactericidal agent(s). For example, live and/or inactivated H. pylori can be subjected to treatment with one or more antibiotics selected from rifampin, amoxicillin, clarithromycin, rifamycin, rifaximin, the rifamycin derivative 3′-hydroxy-5′-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin syn. KRM-1648 and/or the rifamycin derivative 3′-hydroxy-5′-(4-propyl-1-piperazinyl)benzoxazinorifamycin syn. KRM-1657.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to irradiation such as gamma irradiation and/or ultraviolet irradiation and/or by exposure to visible light such as wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm. For example, killed H. pylori is prepared by a process comprising exposing live and/or inactivated H. pylori cells or strains to ultraviolet C (UVC) irradiation such as wavelength in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or to ultraviolet B (UVB) irradiation such as wavelength in a range from about 280 nm to about 315 nm and/or to ultraviolet A (UVA) irradiation such as wavelength in a range from about 315 nm to about 400 nm. Preferably, the live and/or inactivated H. pylori is exposed to UVC light in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or the live and/or inactivated H. pylori is exposed to about 405 nm violet light.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by sonication e.g., at ultrasonic frequencies such as about 20 kHz or more.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by mutagenesis of live and/or inactivated H. pylori cells or strains.
Preferably, the killed H. pylori as described according to any example hereof is prepared by first by exposing live H. pylori cells or strains to irradiation such as gamma irradiation and/or ultraviolet irradiation such as UVC light and/or by exposure to visible light such as wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm, to thereby inactivate H. pylori and then exposing the inactivated H. pylori cells or strains to heat treatment as described according to any example hereof to thereby kill the inactivated H. pylori or render the inactivated H. pylori irreversibly metabolically inactive.
For example, the inactivated H. pylori is exposed to temperature of about 60° C. or more for at least about 60 seconds, preferably at a temperature of about 60° C. or about 70° C. or about 80° C. or about 90° C. or about 100° C. or about 110° C. or about 120° C. or about 130° C. or about 140° C. or about 150° C., said temperature exposure being for a period of at least 2 minutes or at least 3 minutes or at least 4 minutes or at least 5 minutes or at least 6 minutes or at least 7 minutes or at least 8 minutes or at least 9 minutes or at least 10 minutes or at least 20 minutes or at least 30 minutes or at least 40 minutes or at least 50 minutes or at least 1 hour or at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours or at least 7 hours or at least 8 hours or at least 9 hours or at least 10 hours or at least 11 hours or at least 12 hours or at least 13 hours or at least 14 hours or at least 15 hours or at least 16 hours or at least 17 hours or at least 18 hours or at least 19 hours or at least 20 hours or at least 21 hours or at least 22 hours or at least 23 hours or at least 1 day or at least 2 days or at least 3 days or at least 5 days or at least 5 days or at least 6 days or at least 7 days. In one such example, the inactivated H. pylori is exposed to a single such elevated temperature or to at least two different elevated temperatures such as by exposure to a first temperature of about 70° C. e.g., for about 10 minutes, followed by exposure to a second temperature of about 90° C. or about 95° C. e.g., for about 5 minutes.
In one preferred example, the killed H. pylori as described according to any example hereof is prepared by first by exposing live H. pylori cells or strains to ultraviolet irradiation such as UVC light e.g., at about as 257.3 nm to thereby inactivate H. pylori and then exposing the inactivated H. pylori cells or strains to heat treatment as described according to any example hereof to thereby kill the inactivated H. pylori or render the inactivated H. pylori irreversibly metabolically inactive.
Accordingly, in one preferred example, the composition according to any example hereof comprises H. pylori that has been subjected to a process for inactivating H. pylori by irradiation and a process for the killing the inactivated H. pylori by heat treatment.
Alternatively, or in addition, H. pylori as described according to any example hereof is inactivated and/or killed by exposing live or inactivated H. pylori to anaerobic conditions e.g., by changing the atmosphere in which H. pylori is cultured from microaerobic to anaerobic environment for example to mimic the in vivo atmospheric conditions during the washout of H. pylori from the stomach to the lower gut (e.g., small and/or large intestine). For example, live (such as freshly grown) H. pylori is inactivated by exposing (e.g., by growing or incubating) the bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 72 hours or at least about 96 hours or at least about 120 hours. In one such example, the live H. pylori cells are inactivated by exposing the cells to anaerobic conditions and by heat treatment of the cells.
In another example, live or inactivated H. pylori as described according to any example hereof is killed by exposing (e.g., by incubation) the live or inactivated bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 73 hours or at least about 96 hours or at least about 120 hours.
In one preferred example, the composition according to any example hereof comprises H. pylori that has been subjected to a process for inactivating H. pylori by exposing (e.g., by growing or incubating) the bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 73 hours or at least about 96 hours or at least about 120 hours, and a process for the killing the inactivated H. pylori by heat treatment of the cells.
In a further example, the composition according to any example described hereof comprises a pharmaceutically acceptable carrier. In one preferred example, the composition does not include an adjuvant.
In a further example, the composition according to any example described hereof is an oral formulation formulated for ingestion. Alternatively, the composition according to any example described hereof is formulated for inhalation. For example, the composition according to any example described hereof is formulated as a foodstuff or dietary supplement. In one such example, the composition comprises or formulated as an infant formula and/or a protein supplement. In one example, the composition is a dairy food product or a non-dairy food product. In one example, the composition is formulated as a tablet e.g., for ingestion. Alternatively, the composition is in a powder form e.g., for ingestion and/or inhalation. Alternatively, the composition is in liquid form. In one example, the composition does not include an adjuvant.
In one example, the composition according to any example described hereof is formulated for administration (e.g., by consumption) to infants, such as to infants who do not have developed lymphoid structures. For example, the composition according to any example described hereof is formulated for administration to infants aged between 0 to about 5 years, or between 0 to about 4 years, or between 0 to about 3 years, or between 0 to about 2 years, or between 0 to about 1 year. In one example the composition according to any example described hereof is formulated for administration (e.g., by consumption) to infants aged between 0 to about 2 years. In another example, the composition is formulated for administration to infants of an age between about 4 months and about 12 months or between about 4 months and about 18 months or about 4 months and about 24 months. In another example, the composition is formulated for administration (e.g., by consumption) to infants less than about 6 months of age.
In another example, the composition according to any example described hereof is formulated for administration (e.g., by consumption) to children older than about 5 years of age and/or to adolescents and/or to adults.
In another example, the composition according to any example described hereof is formulated for repeated administration, or is administered repeatedly, for example, once per week, or twice per week, or three times per week, or 4 times per week, or 5 times per week, or 6 times per week, or 7 times per week, or more than 7 times per week, or more than twice per day.
In one example, the composition according to any example described hereof is formulated or administered as a multi-dosage unit composition. For example, each dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells. In one example, the composition according to any example described hereof is formulated for administration daily, or is administered daily, wherein a daily dosage of said composition comprises an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each daily dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells.
In one example, the composition according to any example described hereof is formulated for administration, or is administered, over a period of at least about 2 weeks or at least about 4 weeks or at least about 6 weeks or at least about 8 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months, or at least about one year or more than one year. Preferably, the composition according to any example described hereof is formulated for administration, or is administered, over a period of at least about 13 weeks or at least about 3 months.
In one example, the composition according to any example described hereof is formulated for administration, or is administered, in absence of an adjuvant and/or wherein said composition does not comprise an adjuvant.
In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes a balanced development of an immune system in a juvenile subject. In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes acquisition of adaptive immunity and/or innate immunity in a subject. In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes or enhances CD1d receptor activation and/or CD4-negative and CD8-negative natural killer (NK) cells in a subject.
In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes or enhances γδ T-cell activation. In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes or enhances mucosal immunity involving immune recognition and presentation to antigen-presenting cells (APCs). In another example, the composition or a dosage (e.g., daily dosage) of the composition according to any example described hereof promotes a balanced Th1/Th2 immune response to one or more allergens.
In another example, the composition according to any example described hereof comprises an amount of killed H. pylori cells and/or inactivated H. pylori cells and/or a cell lysate of said killed or inactivated cells.
The present invention clearly extends to the manufacture of a composition for use in preventing or treating allergy in a mammal, said manufacture comprising use of an isolated H. pylori cell, a cell lysate thereof, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal.
In one example, the present invention relates to use of an H. pylori cell such as an isolated H. pylori cell, and/or a cell lysate thereof or a combination thereof, wherein said H. pylori cell is inactivated or killed in the preparation of a composition for preventing or treating allergy in a mammal e.g., wherein the inactivated H. pylori cell does not have the same capacity of a live H. pylori cell having the same genotype to colonize the mucosa of a mammal to which it is administered or wherein the inactivated or killed H. pylori is incapable of colonizing the mucosa of a mammal to which it is administered. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated or killed H. pylori cell.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in the subject. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or H. pylori.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the onset of one or more allergic conditions in the subject. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H pylori.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the onset of one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H. pylori cell.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the onset of airway resistance in response to an allergen. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H. pylori.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the onset of lung inflammation in response to an allergen. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H. pylori.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the cell infiltration into lung e.g., in response to an antigen. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H. pylori.
In another example, the present invention relates to use of an inactivated and/or killed H. pylori , such as an isolated and inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof in the preparation of a composition according to any example described hereof for delaying or preventing or interrupting or slowing the onset of an allergic condition characterized by an elevated serum level of allergen-specific IgE antibody and/or an elevated level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or an elevated level of cell infiltrate in lung. Optionally, wherein the cell lysate is a whole cell lysate (WCL) of the inactivated and/or killed H. pylori.
Preferably, in the use according to any example described hereof, the composition is formulated for administration in absence of an adjuvant and does not include an adjuvant.
In one example, in the use according to any example described hereof, the composition is formulated for administration (e.g., by consumption) to infants, such as to infants who do not have developed lymphoid structures and/or infants aged 0 to about 5 years. For example, wherein the infants are aged between 0 to about 5 years, or between 0 to about 4 years, or between 0 to about 3 years, or between 0 to about 2 years, or between 0 to about 1 year. In one example, the infants are aged between 0 to about 2 years. In another example, the infants are aged between about 4 months and about 12 months or between about 4 months and about 18 months or about 4 months and about 24 months. In another example, the infants are less than about 6 months of age.
In one example, in the use according to any example described hereof example, the composition is formulated for administration (e.g., by consumption) to a child older than about 5 years of age and/or to adolescents and/or to adults.
In one example, in the use according to any example described hereof example, the composition is formulated for repeated administration, for example, once per week, or twice per week, or three times per week, or 4 times per week, or 5 times per week, or 6 times per week, or 7 times per week, or more than 7 times per week, or more than twice per day. In one such example, the composition is formulated as a multi-dosage unit composition. For example, each dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells.
In one such example, the composition is formulated for administration daily, wherein a daily dosage of said composition comprises an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each daily dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells.
In one example, in the use according to any example described hereof example, the dosage e.g., daily dosage of the composition is to be administrated to a subject (e.g., by consumption) over a period of at least about 2 weeks or at least about 4 weeks or at least about 6 weeks or at least about 8 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months, or at least about one year or more than one year, preferably over a period of at least about 13 weeks or at least about 3 months.
In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes a balanced development of an immune system in a juvenile subject. In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes acquisition of adaptive immunity and/or innate immunity in a subject. In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes or enhances CD1d receptor activation and/or CD4-negative and CD8-negative natural killer (NK) cells in a subject. In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes or enhances γδ T-cell activation. In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes or enhances mucosal immunity involving immune recognition and presentation to antigen-presenting cells (APCs). In one example, in the use according to any example described hereof, the composition or a dosage (e.g., daily dosage) of the composition promotes a balanced Th1/Th2 immune response to one or more allergens.
In one example, in the use according to any example described hereof, the composition comprises an amount of killed H. pylori cells and/or inactivated H. pylori cells and/or a cell lysate of said killed or inactivated cells.
The present invention also clearly extends to use of the composition according to any example described hereof or to use of isolated H. pylori cell, a cell lysate thereof, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal.
In one example, the present invention provides use of the composition as described according to any example hereof in preventing or treating allergy in a subject.
In another example, the present invention provides use of the composition according to any example described hereof in interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in a subject.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing the onset of one or more allergic conditions in a subject.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing the onset of one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing the onset of airway resistance in response to an allergen.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing the onset of lung inflammation in response to an allergen.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing cell infiltration into lung.
In another example, the present invention provides use of the composition according to any example described hereof in delaying or preventing or interrupting or slowing the onset of an allergic condition characterized by an elevated serum level of allergen-specific IgE antibody and/or an elevated level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or an elevated level of cell infiltrate in lung.
In another example, the present invention provides use of a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, in preventing or attenuating allergic airway hyper-responsiveness in lungs of a subject following exposure of the subject to an allergen. Preferably, wherein said use comprises use of a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides use of a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, in preventing or attenuating allergic airway hyper-responsiveness in lungs of a subject following exposure of the subject to an allergen. Preferably, wherein said use comprises use of a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides use of a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, in preventing or alleviating airway resistance in lungs of an asthmatic subject following exposure of said subject to an allergen. Preferably, wherein said use comprises use of a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides use of a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, in preventing an allergic immune response to an allergen in a subject or reducing severity or incidence of an allergic immune response to an allergen in a subject. Preferably, wherein said use comprises use of a therapeutically effective amount of killed and/or inactivated H. pylori cells.
Preferably, in the use according to any example described hereof, the H. pylori or the lysate or the composition is used in absence of an adjuvant.
In yet another example, the present invention provides a method of preventing allergy in a mammal at risk of developing said allergy comprising the step of administering to said mammal an effective amount of a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal, wherein said composition, upon administration, provides protective immunity against said allergy.
Accordingly in one example, the present invention provides a method of treating or preventing allergy in a mammalian subject, said method comprising administering the composition according to any example described hereof to a subject in need thereof.
In another example, the present invention provides a method of preventing or attenuating allergic airway hyper-responsiveness in lungs of a subject following exposure of the subject to an allergen, said method comprising administering to the subject a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, sufficient to prevent airway hyper-responsiveness in a subject following exposure of said subject to an allergen. Preferably, wherein said method comprises administering a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides a method of preventing or alleviating airway resistance in an asthmatic subject, said method comprising administering to a subject in need thereof a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof, sufficient to prevent airway hyper-responsiveness in lungs of the subject following exposure of said subject to an allergen. Preferably, wherein said method comprises administering a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides a method of preventing an allergic immune response to an allergen in a subject or reducing severity or incidence of an allergic immune response to an allergen in a subject, said method comprising administering to a subject in need thereof a therapeutically effective amount of killed and/or inactivated H. pylori cells, or a cell lysate thereof or a combination thereof. Preferably, wherein said method comprises administering of a therapeutically effective amount of killed and/or inactivated H. pylori cells.
In another example, the present invention provides a method of interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in a subject, the method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing the onset of one or more allergic conditions in a subject, said method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing the onset of one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma in a subject, the method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing the onset of airway resistance in response to an allergen in a subject, the method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing the onset of lung inflammation in response to an allergen in a subject, the method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing cell infiltration into lung of a subject in response to an allergen, the method comprising administering the composition according to any example described hereof to the subject.
In another example, the present invention provides a method of delaying or preventing or interrupting or slowing the onset of an allergic condition in a subject, wherein said condition is characterized by an elevated serum level of allergen-specific IgE antibody and/or an elevated level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or an elevated level of cell infiltrate in lung of the subject, and wherein the method comprising administering the composition according to any example described hereof to the subject.
Preferably, in the method described according to any example hereof, the H. pylori or the lysate or the composition is administered in absence of an adjuvant, and wherein the composition does not comprise an adjuvant.
In one example of the method according to any example described hereof, the composition or the inactivated or killed H. pylori cells and/or the lysate thereof is administered to the subject by the oral route (i.e., for ingestion by the subject) and/or by inhumation.
In one example of the method according to any described hereof, the composition or the inactivated or killed H. pylori cells and/or the lysate thereof is administered (e.g., by consumption) to infants, such as infants who do not have developed lymphoid structures and/or wherein the infant is aged 0 to about 5 years. For example, the infants are aged between 0 to about 5 years, or between 0 to about 4 years, or between 0 to about 3 years, or between 0 to about 2 years, or between 0 to about 1 year. In one example, the infants are aged between 0 to about 2 years. In another example, the infants are in the age between about 4 months and about 12 months or between about 4 months and about 18 months or about 4 months and about 24 months. In another example, the infants are less than about 6 months of age.
In another example, in the method according to any example described hereof the composition or the inactivated or killed H. pylori cells and/or the lysate thereof is administered (e.g., by consumption) to a children older than about 5 years of age and/or to adolescents and/or to adults.
In another example, the method according to any example described hereof comprises repeated administration of the composition or the inactivated or killed H. pylori cells and/or the lysate thereof to the subject. In one example, the composition or the inactivated or killed H. pylori cells and/or the lysate thereof is administered to the subject once per week, or twice per week, or three times per week, or 4 times per week, or 5 times per week, or 6 times per week, or 7 times per week, or more than 7 times per week, or more than twice per day.
In one such example, the method according to any example described hereof comprises administering a dosage of the composition comprising an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells. In one such example, the method according of the present invention according to any described hereof, comprises administering a daily dosage of the composition, wherein the wherein the daily dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof in a range corresponding to between about 10 2 cells to about 10 14 cells, or about 10 3 cells to about 10 13 cells, or about 10 4 cells to about 10 13 cells, or about 10 5 cells to about 10 13 cells, or about 10 6 cells to about 10 13 cells, or about 10 6 cells to about 10 12 cells, or about 10 7 cells to about 10 11 cells, or about 10 8 cells to about 10 10 cells, or about 10 9 cells to about 10 10 cells. For example, each daily dosage of the composition comprises an amount of the H. pylori bacteria or a lysate thereof corresponding to about 10 8 cells, or about 10 9 cells, or about 10 10 cells.
In another example, the method according to any example described hereof comprises administering a daily dosage of the H. pylori or the lysate or composition over a period of over a period of at least about 2 weeks or at least about 4 weeks or at least about 6 weeks or at least about 8 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months, or at least about one year or more than one year, preferably over a period of at least about 13 weeks or at least about 3 months
In another example of the method according of the present invention according to any example described hereof the administration or the H. pylori or the lysate or composition promotes development of a balanced development of an immune system in a juvenile subject.
In another example of the method according to any example described hereof the administration or the H. pylori or the lysate or composition promotes acquisition of adaptive immunity in a subject.
In another example of the method according to any described hereof, the administration or the H. pylori or the lysate or composition promotes acquisition of adaptive immunity in a subject.
In another example of the method according to any described hereof, the administration or the H. pylori or the lysate or composition promotes or enhances CD1d receptor activation and/or CD4-negative and CD8-negative natural killer (NK) cells.
In another example of the method according to any described hereof, the administration or the H. pylori or the lysate or composition promotes or enhances γδ T-cell activation.
In another example of the method according of the present invention according to any described hereof, the administration or the H. pylori or the lysate or composition promotes or enhances mucosal immunity involving immune recognition and presentation to antigen-presenting cells (APCs).
In another example of the method according to any example hereof, the administration or the H. pylori or the lysate or composition promotes a balanced Th1/Th2 immune response to one or more allergens.
In another example of the method according to any described hereof, the subject is asymptomatic for eczema, or asymptomatic for allergy, or asymptomatic for asthma, and wherein said method prevents a subsequent onset of eczema and/or allergy and/or asthma in the subject e.g., following exposure of the subject to an allergen. In one such example, the method comprises administering an isolated and inactivated H. pylori to a juvenile subject to prevent eczema in the infant or a subsequent onset of allergy or asthma in later life. Alternatively, the method comprises administering the isolated and inactivated H. pylori to an adolescent or adult subject to prevent eczema in the subject or a subsequent onset of allergy or asthma in later life in the subject. However, a subsequent onset of eczema and/or allergy and/or asthma may be induced in an untreated subject to whom the H. pylori or the composition has not been administered by exposure of the untreated subject to an allergen. For example, the allergen is an environmental allergen, pollen allergen, dust mite allergen, animal allergen, or chemical allergen.
In another example of the method according to any described hereof, the subject has suffered previously from one or more incidences of allergic eczema, allergy, or asthma, and wherein said method prevents a subsequent attack or reduces severity of a subsequent attack in the subject. In one such example, the method comprises administering the inactivated and/or killed H. pylori , such as isolated inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof, to an adolescent or adult subject that has suffered previously from allergic eczema and/or allergy and/or asthma, to thereby prevent a subsequent attack or reduce severity of a subsequent attack, optionally to prevent or slow further atopic march in the subject. Alternatively, the method comprises administering the inactivated and/or killed H. pylori such as isolated inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof, to an adolescent or adult subject that has suffered previously from allergic eczema and/or allergy and/or asthma, to thereby prevent a subsequent attack or reduce severity of a subsequent attack, optionally to prevent or slow further atopic march in the subject. However, a subsequent attack of eczema and/or allergy and/or asthma may be inducible in an untreated subject to whom the H. pylori or the composition has not been administered by exposure of the untreated subject to an allergen. For example, the allergen is an environmental allergen, pollen allergen, dust mite allergen, animal allergen, or chemical allergen.
In another example of the method according to any described hereof, administration of an inactivated and/or killed H. pylori , such as isolated inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof, to a subject reduces the incidence of allergic immune responses in a population of subjects.
In another example of the method according to any described hereof, administration of an inactivated and/or killed H. pylori , such as isolated inactivated and/or killed H. pylori , or a cell lysate thereof or a combination thereof, to a subject reduces the incidence of allergic immune responses in adolescent and/or adult members of the population treated when they were juveniles.
In some embodiments, the mammal is a naive mammal. Thus, in a further example, the present invention provides a method of preventing allergy in an immunologically naive mammal at risk of developing said allergy, said method comprising the step of: (i) identifying a mammal at risk of developing an allergy; (ii) administering to said mammal a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal and (iii) allowing sufficient time to elapse to enable energy to develop.
In a further example, the present invention provides a method of treating allergy in a mammal comprising the step of administering to said mammal an effective amount of a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal, wherein said composition, upon administration, provides protective immunity against said allergy.
The mammal or subject includes a dog, a cat, a livestock animal, a primate or a horse. In some embodiment, the mammal or subject is a human subject. Preferably, the human subject is below the age of about 5. More preferably, the human subject is below the age of 2 years.
In one example, the present invention provides a kit for treating and/or preventing allergy in a mammal comprising (i) a composition according to any example hereof and (ii) instructions for use in a method according to any one of examples hereof.
The present invention also clearly extends to a kit for treating and/or preventing allergy in a subject, said kit comprising (i) the inactivated and/or killed H. pylori or the lysate or the composition as described according to any example hereof, and optionally (ii) instructions for use in a method or use according to any one of examples hereof. For example, the kit is for use in preventing or attenuating allergic airway hyper-responsiveness in lungs of a subject following exposure of the subject, such as an asthmatic subject, to an allergen. Alternatively, or in addition, the kit is for use in preventing or alleviating airway resistance or airway hyper-responsiveness in lungs of an asthmatic subject following exposure of said subject to an allergen. Alternatively, or in addition, the kit is for use in preventing an allergic immune response to an allergen in a subject or reducing severity or incidence of an allergic immune response to an allergen in a subject. Alternatively, or in addition, the kit is for use in interrupting or slowing or arresting or preventing an atopic march or progression of an atopic march in a subject. Alternatively, or in addition, the kit is for use in delaying or preventing or interrupting or slowing the onset of one or more allergic conditions in a subject, for example wherein the one or more condition(s) is/are characterized by an elevated serum level of allergen-specific IgE antibody and/or an elevated level of one or more inflammatory cytokines in bronchioalveolar lavage (BAL) and/or an elevated level of cell infiltrate in lung of the subject. Alternatively, or in addition, the kit is for use in delaying or preventing or interrupting or slowing the onset of one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma in a subject. Alternatively, or in addition, the kit is for delaying or preventing or interrupting or slowing the onset of airway resistance and/or lung inflammation response to an allergen in a subject. Alternatively, or in addition, the kit is for delaying or preventing or interrupting or slowing cell infiltration into lung of a subject in response to an allergen.
In a further example, the present invention provides a method of generating a H. pylori strain that is able to provide protective immunity against allergy comprising the steps of:
(a) providing an isolated H. pylori cell that is;
(i) incapable of colonizing the mucosa of a mammal and/or (ii) cagA minus (cagA) and optionally positive for the toxigenic s1 and m1 alleles of the vacA gene;
(b) optionally passaging said H. pylori cell through an animal host; and (c) optionally inactivating or killing said H. pylori cell.
Unless the context requires otherwise or specifically stated to the contrary, integers, steps, or elements of the invention recited herein as singular integers, steps or elements clearly encompass both singular and plural forms of the recited integers, steps or elements.
As used herein the term “derived from” shall be taken to indicate that a specified integer may be obtained from a particular source albeit not necessarily directly from that source.
Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated step or element or integer or group of steps or elements or integers but not the exclusion of any other step or element or integer or group of elements or integers.
Throughout this specification, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group of compositions of matter shall be taken to encompass one and a plurality (i.e. one or more) of those steps, compositions of matter, groups of steps or group of compositions of matter. Accordingly, as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. For example, a reference to “a bacterium” includes a plurality of such bacteria, and a reference to “an allergen” is a reference to one or more allergens.
Each example described herein is to be applied mutatis mutandis to each and every other example unless specifically stated otherwise.
Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features.
The present invention is not to be limited in scope by the specific examples described herein, which are intended for the purpose of exemplification only. Functionally-equivalent products, compositions and methods are clearly within the scope of the invention, as described herein.
All publications, patents and patent applications cited herein, whether supra or infra, are hereby incorporated by reference in their entirety. However, publications mentioned herein are cited for the purpose of describing and disclosing the protocols, reagents and vectors which are reported in the publications and which might be used in connection with the invention. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 , panel A, shows the “allergic (or atopic) march” which refers to the typical progression of allergic diseases that often begin early in life and illustrates the relative prevalence of clinical symptoms and manifestations of allergic diseases according to age of individuals. The allergic diseases include atopic dermatitis (eczema), food allergy, allergic rhinitis (hay fever) and asthma. In general, no clinical symptoms are detectable at birth. A majority of children with eczema will progress to develop food allergies and/or allergic asthma, and a significant proportion of these individuals will have atopic or respiratory allergies as adults. Also, asthmatic wheezing may already be observed during early infancy and although the majority of early wheezers turn out to be transiently symptomatic, in some children wheezing may persist throughout school age and adolescence.
FIG. 1 , panel B, shows the gradient or relative distribution of H. pylori in the gastrointestinal tract. H. pylori bacterial is a mammalian gut commensal organism that may be present in the gut alongside many other bacteria. H pylori is generally acquired by the oral route and colonized the gut, and may be asymptomatic in over 80% if humans, although persistent colonization of the stomach is associated with higher risk of peptic ulcers, gastric cancers and other disorders such as chronic urticarial (hives). H. pylori is continuously shed in large amounts from the stomach into the lower intestines where it may be taken up by the Peyer's patches and may modulate the immune system via the Peyer's patches to establish persistent gastric infection (Gerirtz A T and Sitaraman S V, 2007 , Gastroenterology 133: 1044-1045; Nagi S et al., 2007 , Proc Natl Acad Sci USA 109: 8971-8976; Watanabe N et al., 2008 , Gastroenterology 134: 642-643). Active colonization by H. pylori may modulate the host immune system towards immune tolerance of H. pylori to allow persistent colonization, and is associated with reduce risk of allergic conditions in the host (Amedei A et al., 2010 , J Asthma Allergy. 3:139-147; Kosunen T U et al., 2002 , Clin Exp Allergy. 32:373-378; Chen and Blaster M J, 2007 , Arch Intern Med. 167:821-827).
FIG. 1 , panel C, shows an acute allergic asthma model using an OVA sensitization/challenge in which untreated H. pylori (marked “live Hp”) and treated H. pylori i.e., inactivated and/or killed H. pylori (marked “killed Hp”) are each administered to a mouse model of allergy and challenged at the time points indicated.
FIG. 2 shows replication efficacy of live untreated H. pylori OND86 control cells (marked “live”) and treated H. pylori i.e., inactivated and/or killed H. pylori following treatment by UV-C irradiation (marked “UV”) and optionally heat treatment (marked “UV+HEAT”) or following incubation for 48 hours under anaerobic conditions (marked “O 2 Restriction”) and optionally heat treatment (marked “O 2 Restriction+HEAT”). Replication efficacy of live and treated cells are determined by cells count i.e., colony forming units (CFU) measured on CBA plates after incubation of live and treated H. pylori i.e., inactivated and/or killed H. pylori for 3 days at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 . Results obtained from two independent experiments are shown (marked “Repeat 1” and “Repeat 2”).
FIG. 3 shows percentage of urease activity in treated i.e., inactivated and/or killed H pylori following heat treatment (marked “Heat”), UV-C irradiation (marked “UV”) and optionally heat treatment (marked “UV+HEAT”) or following oxygen starvation (marked “O 2 Res”) and optionally heat treatment (marked “O 2 Res+HEAT”) relative to urease activity in untreated live H. pylori cells (marked “Live”).
FIG. 4 shows membrane redox potential ratio of live H pylori cells (marked “Live”) or H. pylori exposed to treatment by oxygen starvation (marked “O2r” or “O2R”) UV-C irradiation (marked “UV”) before and after heat treatment (marked “heat”).
FIG. 5 shows that untreated H pylori (marked “live H. pylori ”) and treated H. pylori i.e., inactivated and/or killed H pylori (marked “killed H. pylori ”) each improve outcomes of allergic asthma in the OVA model of allergic airways disease.
FIG. 6 shows that untreated H. pylori (marked “Hp”) and treated H. pylori i.e., inactivated and/or killed H. pylori (marked “killed”) each reduce total cell counts (panel A) and eosinophilia (panel B) in the OVA model of allergic airways disease.
FIG. 7 shows a decreased OVA-specific IgE (panel A) and OVA-specific IgG (panel B) response in mice infected with either untreated H. pylori (marked “Hp”) and treated H. pylori i.e., inactivated and/or killed H pylori (marked “killed”) in the allergic asthma model.
FIG. 8 shows that IL-13 is reduced in the lungs of mice infected with either untreated H pylori (marked “live H pylori ”) and treated H pylori i.e., inactivated and/or killed H. pylori (marked “killed”) in the allergic asthma model.
FIG. 9 shows the decreased number (panel A) and function (panel B) of OVA-specific CD8 T cells in H. pylori infected mice (marked “live H. pylori ”) compared to control mice (marked “naive”) after OVA/alum challenge.
FIG. 10 shows decreased antigen-specific IgG in H. pylori -infected mice (marked “live H. pylori ”) compared to control mice (marked “naive”), after primary (panel A) and secondary (panel B) OVA/alum challenge.
FIG. 11 shows the reduced responsiveness of CD4 (panel A) and CD8 T (panel B) cells from H. pylori infected mice (marked “live H. pylori ”) compared to control mice (marked “naive”) in response to a non-specific stimulus.
FIG. 12 shows that H. pylori colonisation improves outcomes of allergic airways disease in the neonatal allergic asthma model. Panel A shows that airway resistance increased in allergic adult mice not infected with live H. pylori , whereas mice challenged with live H. pylori from day 5 exhibited comparable airway resistance to that of non-allergic mice. Panel B shows that H. pylori colonization prevents cellular infiltration in the lungs after allergen challenge and that the total cell count was similar to non-allergic control mice.
FIG. 13 shows that untreated H. pylori (marked “live H. pylori ” in the x-axes) and treated H. pylori i.e., inactivated and/or killed H. pylori (marked “killed” in the x-axes) each improve immunological outcomes in the neonatal allergic asthma model. Panel A shows that administration of either treated or live H. pylori effectively reduced cellular infiltration in the lungs of H. pylori treated mice. Panel B shows that administration of either treated H. pylori or live H. pylori also reduced allergic allergen-specific IgE antibodies in H. pylori treated subjects. Panels C and D demonstrate that administration of treated (or live) H. pylori was successful in reducing production of cytokine mediators and biological markers of asthma and allergic respiratory disease, IL-5 and IL-13, in the lungs.
FIG. 14 shows that untreated H. pylori (marked “live Hp”) and treated H. pylori i.e., inactivated and/or killed H. pylori (marked “killed Hp”) are each effective in reducing allergic airway response to an allergen in adult and in neonatal mice. Panel A, shows results of airway hyperresponsiveness (AHR) of lung tissue in response to increasing doses of metacholine (MCh) challenge in adult mice infected with untreated H. pylori and treated H. pylori i.e., inactivated and/or killed H. pylori . Allergic adult mice controls which did not receive H. pylori i.e., were uninfected, sensitised and challenged were marked “Positive” and untreated healthy adult mice controls which did not receive H. pylori i.e., were uninfected and were only sensitised were marked “Negative”. Panel B, shows results of airway hyperresponsiveness (AHR) of lung tissue in response to increasing doses of metacholine (MCh) challenge in neonatal mice infected with untreated H. pylori . Panel C, shows results of airway hyperresponsiveness (AHR) of lung tissue in response to increasing doses of metacholine (MCh) challenge in neonatal mice infected with untreated H. pylori and with treated H. pylori i.e., inactivated and/or killed H. pylori . In panels A and B, allergic adult neonatal mice controls which did not receive H. pylori i.e., were uninfected, sensitised and challenged were marked “Positive”, and untreated healthy neonatal mice controls which did not receive H. pylori i.e., were uninfected and were only sensitised were marked “Negative”. The results shown in panels A, B and C represent three independent experiments.
FIG. 15 shows results of colonization efficacy of untreated H. pylori (marked “live”) and treated H. pylori i.e., inactivated and/or killed H. pylori (marked “treated”) in allergic subjects in the adult allergic asthma model.
FIG. 16 shows results of colonization efficacy in mice of inactivated and/or killed H. pylori produced by treatment of live OND79 H. pylori cells with UV-C irradiation (marked “OND79 UV”) and optionally heat treatment (marked “OND79 UV+HEAT”) or by oxygen starvation (marked “OND79 O2R”) and optionally heat treatment (marked “OND79 O2R+HEAT”). Colonization efficacy is shown as the number of colony forming unity (CFU) detected in stomach of infected mice.
FIG. 17 shows that UV treated i.e., inactivated and/or killed H. pylori OND79 (marked “OND79”) and H. pylori J99 (marked “J99”) strains of different origins were effective in reducing allergen (OVA)-specific IgE (Panel A) and IgG (Panel B) antibodies in neonatal allergic asthma mouse model. Control mice were uninfected, sensitised and challenged (positive control i.e., untreated allergic mice; marked “Pos”) or only sensitised (negative control i.e., untreated healthy mice; marked “Neg”). Titres of OVA-specific antibodies were measured in mice serum diluted 1:60, and expressed as the individual and average absorbance at OD405 nm.
FIG. 18 shows randomly amplified polymorphic DNA (RAPD) analysis of a single colony isolate of H. pylori OND79 and single colony isolates six clinical isolates of a derivative H. pylori obtained from a gastric biopsy sample following passaging of H. pylori OND79 in a human host. The six clinical isolates of the derivative H. pylori were labelled “#1157 clone 1”, “#1157 clone 9”, “#86198 clone 1”, “#86198 clone 9”, “#45156 clone 1” and “#45156 clone 9”. Genetic fingerprinting was performed as described by Akopyanz et al., (1992) Nucleic Acids Research, 20:5137-5142 using the primer “1254” set forth in SEQ ID NO: 3 and having the sequence 5′-CCG CAG CCA A-3′ (Panel A), or the primer “1281” set forth in SEQ ID NO: 4 and having the sequence 5′-AAC GCG CAA C-3′ (Panel B). In each of Panel A or Panel B: lane M, 1 kilo base (kb) DNA ladder marker (New England Biolabs Inc., Ipswich, Mass., US); lane 1, OND79 (parent strain); lane 2, #1157 clone 1; lane 3, #1157 clone 9; lane 4, #86198 clone 1; lane 5, #86198 clone 9; lane 6, #45156 clone 1; lane 7, #45156 clone 9. Genetic fingerprinting was identical for the parent input strain OND 79 and for each clinical isolate of the human-passaged derivative strain.
FIG. 19 shows results of infection and colonization efficacy in mice of six clinical isolates of H. pylori obtained after passaging H. pylori OND79 in a human host. Infection and colonization efficacy of the clinical isolates is shown as the number of colony forming unity (CFU) detected in stomach of infected mice. The six H. pylori clinical isolates are labelled “#1157 clone 1”, “#1157 clone 9”, “#86198 clone 1”, “#86198 clone 9”, “#45156 clone 1” and “#45156 clone 9”. The H. pylori clinical isolate #1157 clone 9 corresponds to H. pylori OND86 strain deposited under NMI Accession No. V14/013016.
FIG. 20 shows efficacy of six clinical isolates of H. pylori obtained after passaging H. pylori OND79 in a human host, to induce specific anti- H. pylori IgG antibody response 2 weeks after oral administration of the isolates in the C57BL/6 mouse model. Antibody response titres are expressed as the OD value measured at 405 nm. The six H. pylori clinical isolates are labelled “#1157 clone 1”, “#1157 clone 9”, “#86198 clone 1”, “#86198 clone 9”, “#45156 clone 1” and “#45156 clone 9”. The H. pylori clinical isolate #1157 clone 9 corresponds to H. pylori OND86 strain deposited under NMI Accession No. V14/013016.
FIG. 21 shows safety and tolerability study in allergic adult subjects including a dose escalation assessment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
1. H. pylori
The present invention provides for compositions comprising inactivated and/or killed H. pylori or a cell lysate thereof.
In one example, the H. pylori is an inactivated H. pylori . The term “inactivated H. pylori ” shall be taken to mean a cell or strain of H. pylori which does not have the same capacity of a live H. pylori bacterium having the same genotype to induce gastric ulcer or other pathology such as a malignancy and/or does not have the same colonization capability of a live bacterium H. pylori bacterium having the same genotype and/or does not have a functional or intact genome of a live H. pylori bacterium having the same genotype. For example, an inactivated H. pylori may not have an intact genome yet retain a functional transcriptome and/or translational machinery such that it retains at least portion of the metabolic activity of the corresponding live H. pylori . Thus, it is preferred that an inactivated H. pylori retains partial or full metabolic activity of a corresponding live H. pylori . By “live H. pylori ” in this context is meant H. pylori that has not been treated as described according to any example hereof so as to render it inactive and/or killed.
Notwithstanding that an inactivated H. pylori may transiently associate with the gastric mucosa of a mammal, it is preferred that such inactivated bacteria are incapable of colonizing the gastric mucosa of a mammal so as to establish chronic or persistent infection of the gastric mucosa. For example, inactivated H. pylori may have an impaired ability to induce one or more H. pylori -associated pathogenic effects including, but not limited to, formation of peptic ulcers, gastric cancers such as non-cardiac gastric adenocarcinoma or MALT lymphoma, and other disorders such as chronic urticarial (hives) that is normally associated with persistent H. pylori colonization of the mucosa.
Preferably, an inactivated H. pylori retains the cell structure of live H. pylori . For example, an inactivated H. pylori retains the structural integrity of the bacterial cell wall and/or cell membrane of live H. pylori such that it may not be disrupted or lysed.
Alternatively, or in addition, the inactivated H. pylori retains an ability of a live H. pylori to be taken up by the Peyer's patches in the lower intestine of a mammal. For example, the inactivated H. pylori may retain the immunogenicity and/or antigenicity and/or receptor-ligand interaction of a corresponding live H. pylori having replicative and colonizing functionalities.
Alternatively, or in addition, an inactivated H. pylori undergoes one or more metabolic changes e.g., enhanced lipopolysaccharide synthesis and surface presentation thereof and/or enhanced degradation of cellular proteins and/or reduced urease production during and/or following their inactivation.
In another example, the H. pylori is a killed H. pylori . The term “killed H pylori ” shall be taken to mean a cell or strain of H. pylori , which is irreversibly metabolically inactive. For example, a killed H. pylori is incapable of inducing gastric ulcer or other pathology such as a malignancy and/or is incapable of colonizing the gastric mucosa of a mammal and/or does not have a functional or intact genome of a live H. pylori bacterium having the same genotype. Thus it is preferred that a killed H. pylori does not retain a functional transcriptome and/or translational machinery.
Preferably, a killed H. pylori retains the cell structure of an a live H. pylori . For example, a killed H. pylori retains the structural integrity of the bacterial cell wall and/or cell membrane of an inactivated or live H. pylori such that it may not be disrupted or lysed.
Alternatively, or in addition, a killed H. pylori retains the ability of a live H. pylori to be taken up by the Peyer's patches in the lower intestine of a mammal. For example, the killed H. pylori may retain the immunogenicity and/or antigenicity and/or receptor-ligand interaction of a corresponding live H. pylori having replicative and colonizing functionalities.
In another example, the present invention employs H. pylori that has been subjected to a process for inactivating the bacterium and a process for killing H. pylori . For example, killing of cells captures the benefits of the inactivated cells to the immune system following their administration whilst ensuring added safety of the organism for human use.
In the present context, a “cell lysate” is a preparation made from inactive and/or killed H. pylori cells as described according to any example hereof in which the inactive and/or killed H. pylori cells have been disrupted such that the cellular components of the bacteria are disaggregated or liberated from the bacterial cell.
Persons skilled in the art are aware of means for producing bacterial cell lysates. For example, H. pylori cells are pelleted and then resuspended in, for example, Dulbecco's phosphate buffered saline (PBS; 10 mM phosphate, 0.14 M NaCl, pH 7.4) and subjected to sonication on ice with a W-375 sonication Ultrasonic processor (Heat Systems-Ultrasonics, Inc., Farmingdale, N.Y.) at 50% duty cycle with pulse and strength setting 5 for three 1 min sessions. If required, insoluble material and unbroken bacterial cells can then be removed by centrifugation. Alternatively, H pylori cells are pelleted and then resuspended in a lysis buffer containing 25 mM Tris, pH 7.5, 1 mM MgCl 2 , 1 mM aminopolycarboxylic acid (EGTA), 150 mM NaCl, 1% v/v nonyl phenoxypolyethoxyl ethanol (e.g., Tergitol-type NP-40 from Sigma-Aldrich Inc.,) and 1% v/v protease and/or phosphatase inhibitor(s). The whole cell lysate is collected e.g., using a cell scraper and centrifuged at 1,200 g, 4° C. for 15 min. Alternatively, H. pylori cells are collected by centrifugation and resuspended in PBS and then lysed by passage through a French press (SLM Instrument Inc., Urbana, Ill.) at 20,000 LB/in. Again, if required, the bacterial lysate are centrifuged at 102,000×g for 10 minutes to remove bacterial debris and/or filtered through a 0.45 μM membrane (Nalgene, Rochester, N.Y.). Another method of producing cell lysate of H. pylori involves one or more cycles of freezing and thawing of bacterial pellets e.g., in the presence of lysozyme. A particular example of a H. pylori cell lysate is the soluble fraction of a sonicated culture of the inactivated H. pylori , e.g., obtained after filtration. Alternatively or in addition, H. pylori cells are fragmented using a high-pressure homogenizer (e.g., Avestin model EmulsiFlexC5). Optionally, the cell lysate is further treated using formalin. In one example, the whole cell lysate (WCL) of H. pylori e.g., obtained as described herein, is subjected to additional fractionation and/or purification to isolate or purify or separate one or more components from the H. pylori cell lysate, such as cell proteins and/or lipids.
In another example, the live and/or inactivated and/or killed H. pylori may be in an isolated form. As used herein the term “isolated” when used in reference to H. pylori such as live and/or inactivated and/or killed H. pylori refers to H. pylori or cell or strain thereof present in an environment which is different to the native environment in which a live H. pylori is naturally present. For example, the isolated H. pylori may be removed or isolated from its native environment and/or substantially free of at least one component found in the native environment of a live H. pylori . The term “isolated” in this context includes a H. pylori cell culture, a partially-pure H. pylori cell preparation, and a substantially pure H. pylori cell preparation.
In one particular example, H. pylori is provided in biologically-pure form. As used herein the term “biologically-pure” refers to an in vitro or ex vivo culture of H. pylori that is substantially free from other species of microorganisms. Optionally, a biologically-pure H. pylori is in form of a culture of a single strain of H. pylori.
In yet another example, a killed and/or inactivated H pylon may comprise a cell lysate. For example, the cell lysate may be a whole cell lysate of H. pylori.
Alternatively, the present invention is employed using a composition comprising a mixture of the inactivated and/or killed H. pylori as described according to any example hereof and a cell lysate, such as a whole cell lysate of an inactivated and/or killed H. pylori as described according to any example hereof.
2. Cultivating H. pylori
Strains
Any H. pylori strain known in the art may be used in the preparation of the H. pylori compositions of the present invention. In one example, the H. pylori strain may be any live H. pylori strain deposited with an International Depositary Authority under the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the Purpose of Patent Procedure. For example, the H. pylori strain may be obtained from the American Type Culture Collection (ATCC) such as, for example, H. pylori deposited under Accession No. ATCC 43504 or Accession No. ATCC 26695 or Accession No. ATCC BAA-945 or Accession No. ATCC 700392 or Accession No. ATCC 49503 or Accession No. ATCC 53726 or Accession No. 53727 or Accession No. ATCC 43526 or Accession No. ATCC: 43579 or accession number ATCC 700824. For example, H. pylori strain may be J99 stain (ATCC 700824). Alternatively, or in addition, exemplary H. pylori strains are as described by Moodley Y et al., (2009), Science, 323: 527-530 and/or by Falush D, et al., (2003), Science, 299: 1582-1585. Alternatively, or in addition, exemplary H. pylori strains that may be used in the preparation of the compositions of the present invention were deposited with the National Measurement Institute (NMI), 1/153 Bertrie Street, Port Melbourne, Victoria, Australia, pursuant to the provisions of the Budapest Treaty as follows:
H. pylori strain name
NMI Accession No
Date of deposit
OND737
V09/009101
22 Apr. 2009
OND738
V09/009102
22 Apr. 2009
OND739
V09/009103
22 Apr. 2009
OND740
V09/009104
22 Apr. 2009
OND248
V10/014059
28 May 2010
OND256
V10/014060
28 May 2010
OND79
V13/023374
28 Nov. 2013
OND86
V14/013016
10 Jun. 2014
In another example, the H. pylori may be any H. pylori clinical isolate obtained from mammalian e.g., human gastric biopsy samples from patients diagnosed to be infected with H. pylori such as those exhibiting chronic gastritis, peptic ulcers e.g., gastric and duodenal ulcers, and/or gastric malignancies. In one such example, the H. pylori bacteria in the patient biopsy is inoculated onto a suitable culture medium such as Columbia agar containing 5% sheep blood (Invitrogen) and grown at 37° C. in a microaerophilic chamber (Don Whitley, West Yorkshire, UK) in 10% CO 2 , 5% O 2 , and 85% N 2 ; for example as described by Cheng-Chou Yu et al., (2013), PLoS ONE, 1: e55724. In another example, the H. pylori bacteria in the patient biopsy is inoculated onto H. pylori selective media such as F12 agar medium plates comprising DENT's supplement, nalidixic acid and bacitracin e.g., commercially available from Thermoscientific, Australia. In one such example the H. pylori strain is TA1 (Cag+ and VacA+) as described by Cheng-Chou Yu et al., (2013) supra.
Accordingly, in some examples, the H. pylori strain of the present invention has been passaged through an animal host such as a human. For example, the H. pylori strain of the present invention is derived from the H. pylori strain OND79 after passage of the OND79 strain in a human subject e.g., following infection and/or colonization of the gastric mucosa of a human subject with H. pylori OND79 strain. In one such example the H. pylori strain is obtained from a human gastric biopsy sample of a human subject who has been administered with OND79 cells. For example, the H. pylori strain of the present invention is OND86.
Culture Media
Media used for cultivating H. pylori for bacterial growth and/or maintenance are prepared by procedures known to the skilled artisan and described, for example, in BD Diagnostics ( Manual of Microbiological Culture Media , Sparks, Md., Second Edition, 2009); Versalovic et al. (In Manual of Clinical Microbiology , American Society for Microbiology, Washington D.C., 10th Edition, 2011), Garrity et al. (In Bergey's Manual of Systematic Bacteriology , Springer, New York, Second Edition., 2001); Ndip et al. 2003 J. Pediatr. Gastroenterol. Nutr. 36: 616-622 and Testerman et al. 2001 J. Clin. Microbiol. 39: 3842-3850. As will be apparent to the skilled artisan, H. pylori morphology may be assessed by performing gram staining (See e.g. Coico 2005 Curr. Protoc. Micorbiol . Appendix 3) and viability of may be assessed using colony counts as described, for example, by Murray et al. (In: Manual of Clinical Microbiology, American Society for Microbiology, Washington D.C., Ninth Edition 2007).
A preferred cell culture medium is supplemented with bovine serum, or a modified cell culture medium comprising a serum alternative suitable for cultivation of mammalian cells and comprising sufficient carbon and energy sources to support growth of H. pylori in a fermentation process. Preferred cell culture media have regulatory approval for use in production of human therapeutics.
For example, H. pylori may be cultured on a defined medium supplemented with bovine serum and fortified with Fe3+. Exemplary medium is an F12 liquid medium supplemented with NaHCO 3 , fetal bovine serum (FBS) 10% (v/v) and FeSO 4 (75 μM).
In a particularly preferred example, medium for cultivation of H pylori comprises calcium chloride (e.g., calcium chloride anhydrous), cupric sulfate (e.g., as cupric sulfate.5H 2 O), ferrous sulfate (e.g., FeSO 4 .7H 2 O), magnesium chloride (e.g., magnesium chloride anhydrous), potassium chloride, sodium chloride, sodium phosphate (e.g., sodium phosphate dibasic [anhydrous]), zinc sulfate.7H 2 O (e.g., zinc sulfate.7H 2 O), L-alanine, L-arginine (e.g., L-arginine.HCl), L-asparagine (e.g., L-asparagine. H 2 O), L-aspartic acid, L-cysteine (e.g., L-cysteine.HCl or L-cysteine. HCl.H 2 O), L-glutamic acid, L-glutamine, glycine, L-histidine (e.g., L-histidine. HCl or L-histidine.HCl.H 2 O), L-isoleucine, L-leucine, L-lysine (e.g., L-lysine. HCl), L-methionine, L-phenylalanine, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine (e.g., L-tyrosine 2Na.2H 2 O), L-valine, D-biotin, choline chloride, folic acid, myo-inositol, niacinamide, D-pantothenic acid (hemicalcium), pyridoxine (e.g., pyridoxine.HCl), riboflavin, thiamine (e.g., thiamine.HCl), vitamin B-12, D-glucose, hypoxanthine, linoleic acid, phenol red (e.g., phenol red.Na), putrescine dihydrochloride, pyruvic acid (e.g., pyruvic acid.Na) thioctic acid, thymidine and bovine serum.
In one such preferred example, the medium for cultivation of H. pylori comprises 0.0333 g/L calcium chloride (anhydrous), 0.0000025 g/L cupric sulfate.5H 2 O, 0.000834 g/L ferrous sulfate.7 H 2 O, 0.0576 g/L magnesium chloride [anhydrous], 0.224 g/L potassium chloride, 7.599 g/L sodium chloride, 0.14204 g/L sodium phosphate dibasic (anhydrous), 0.000863 g/L zinc sulfate.7H 2 O, 0.009 g/L L-alanine, 0.211 g/L L-arginine. HCl, 0.01501 g/L L-asparagine.H 2 O, 0.0133 g/L L-aspartic acid, 0.035 g/L L-cysteine.HCl.H 2 O, 0.0147 g/L L-glutamic acid, 0146 g/L L-glutamine, 0.00751 g/L glycine, 0.02096 g/L L-histidine.HCl.H 2 O, 0.00394 g/L L-isoleucine, 0.0131 g/L L-leucine, 0.0365 g/L L-lysine.HCl, 0.00448 g/L L-methionine, 0.00496 g/L L-phenylalanine, 0.0345 g/L L-proline, 0.0105 g/L L-serine, 0.0119 g/L L-threonine, 0.00204 g/L L-tryptophan, 0.00778 g/L L-tyrosine 2Na.2H 2 O, 0.0117 g/L L-valine, 0.0000073 g/L D-biotin, 0.01396 g/L choline chloride, 0.00132 g/L folic acid, 0.018 g/L myo-inositol, 0.000037 g/L niacinamide, 0.00048 g/L D-pantothenic acid (hemicalcium), 0.000062 g/L pyridoxine.HCl, 0.000038 g/L riboflavin, 0.00034 g/L thiamine.HCl, 0.00136 g/L vitamin B-12, 1.802 g/L D-glucose, 0.00408 hypoxanthine, 0.000084 g/L linoleic acid, 0.0013 g/L phenol red.Na, 0.000161 g/L putrescine dihydrochloride, 0.11 g/L pyruvic acid.Na, 0.00021 g/L thioctic acid, 0.00073 g/L thymidine and bovine serum 100 ml.
In media for culturing H. pylori , FBS may be substituted for bovine serum albumin with or without lipid supplementation. Alternatively, plasma may be substituted for FBS, because plasma comprises components of the coagulation cascade that may influence the physiology of the cells e.g., their lipid profile and/or protein profile and/or LPS profile.
Other semi-synthetic media, based on plant proteins or other cell culture media, may also be employed.
H. pylori may be cultivated in a liquid, semisolid or solid form. Examples of liquid media include Brucella Broth, Columbia Broth, brain heart infusion broth, Wilkins-Chalgren broth, Ham's F-10 nutrient media, Ham's F-12 nutrient media, Mueller-Hinton broth, Skirrow Campylobacter media, Belo Horizonte media, Dent's CP media and H. pylori special peptone broth as described for example by Stevenson et al. 2000 Lett. Appl. Microbiol. 30: 192-196. Semisolid and solid media may be prepared from any of the liquid media described in any example hereof, by the addition of a solidifying agent such as, for example, agar. Alternatively, a specialised semisolid and/or solid medium may be used, such as, for example, Chocolate agar, Tryptic Soy Agar, Glupszynski's Brussels campylobacter charcoal agar and Johnson-Murano agar.
The medium may be supplemented with blood or a blood component. As used herein term “blood” shall be taken to mean whole blood and “blood component” refers to serum and/or plasma and/or plasma fractions and/or red blood cells and/or white blood cells and/or platelets and/or protein fractions. Preferably, the blood or blood component is defibrinated. In one example, the blood component is from a mammal.
Suitable mammals include, for example, goats, sheep, bison, cows, pigs, rabbits, buffalos, horses, rats, mouses, or humans. In a preferred example, the blood component may comprise serum. In one example, the serum may be fetal calf serum or newborn calf serum or bovine serum. Media may be supplement with blood or a blood product at final concentration in the media of 1% (vol/vol) or at least 2% (vol/vol) or at least 3% (vol/vol) or at least 4% (vol/vol) or at least 5% (vol/vol) or at least 6% (vol/vol) or at least 7% (vol/vol) or at least 8% (vol/vol) or at least 9% (vol/vol) or at least 10% (vol/vol) or at least 15% (vol/vol) or at least 20% (vol/vol) or at least 25% (vol/vol). In another example, the blood may comprise heat inactivated blood. In another example, the medium may comprise a mixture of heat inactivated and non-heat inactivated blood. Methods of heat inactivating blood are known in the art and are described, for example in Ayache et al. 2006 J. Transl. Med. 4:40.
Alternatively, H. pylori may be cultivated in blood-free medium, such as an egg yolk emulsion medium as described, for example, by Westblom et al. 1991 J. Clin. Microbiol. 29:819-821, or a cyanobacterial extract based medium as described for example, by Vega et al. 2003 J. Clin. Micrbiol. 41: 5384-5388.
In another example, the medium may be supplemented with chemical supplements, such as for example, adenine and/or cysteine hydrochloride and/or cyclodextrin and/or ferric nitrate and/or ferrous sulfate and/or peptone and/or IsoVitaleX and/or Vitox and/or starch and/or sodium bicarbonate and/or sodium pyruvate and/or mucin and/or Vitamin B12 and/or L-glutamine and/or guanine and/or p-aminobenzoic acid and/or L-cystine and/or yeast extract.
In yet another example, the medium may be supplemented with antibiotics capable of inhibiting growth of non- H. pylori microorganisms. Suitable antibiotics may include, vancomycin and/or trimethoprim and/or cefsulodin and/or amphotericin B and/or polymyxine.
Preferably, H. pylori is cultured in medium without antibiotics.
Environmental Conditions
As will be known to the skilled artisan, H. pylori may be cultivated in a micro-aerobic atmosphere such as, for example, in a CO 2 incubator or in an anaerobic chamber with a micro-aerobic atmosphere or in a gas jar with gas-generation kits as described.
Suitable micro-aerobic atmospheres are described, for example, by Mobley et al. (In H. pylori: Physiology and Genetics . American Society for Microbiology, Washington D.C., 2001). In one example, H. pylori may be cultivated in an atmosphere comprising about 1% to about 10% oxygen, about 5% to about 10% carbon dioxide, and about 0% to about 10% hydrogen.
Temperature conditions used to cultivate H. pylori are known in the art. For example, H. pylori may be cultivated at a temperature of between about 25° C. to about 45° C. Preferably, H. pylori may be cultivated at a temperature of between about 30° C. to about 40° C. More preferably, H. pylori may be cultivated at a temperature of about 37° C.
In one example, H. pylori may be stressed during cultivation. As used herein, the term “stressed” shall be taken to mean a change in an environmental condition. For example, H. pylori may be exposed to environmental stresses such as, for example, oxidative stress, pH stress, osmotic stress, carbon starvation, phosphate starvation, nitrogen starvation, amino acid starvation, oxygen stress e.g., by growing H. pylori under anaerobic conditions, heat or cold shock or mutagenic stress. Preferably, exposure of H. pylori to environmental stress(es) during cultivation results in one or more metabolic changes in H. pylori such as enhanced lipopolysaccharide synthesis and surface presentation thereof and/or degradation of H. pylori cellular proteins.
Cell Culture Containers
H. pylori may be cultivated in using standard cell culture containers known to the skilled artisan, such as, for example multi-well plates, petri-dish, roller bottles, T flasks, D flasks, culture chambers, hyperflask vessels, spinner flasks and Erlenmeyer flasks.
Preferred cell culture conditions are optimized for cell culture medium, shear sensitivity, oxygen and other gas requirements, and pH control, to provide for optimum growth of H. pylori in large-scale culture e.g., a high optical density of cell culture in a short time frame.
Preferably, H. pylori may be cultivated in a bioreactor. As used herein the term “bioreactor” shall be taken to mean an apparatus for the cultivation of prokaryotic and/or eukaryotic cell cultures under controlled conditions. The bioreactor may be operated in a batch or fed batch or an extended batch or a repetitive batch or a draw/fill or a rotating-wall or a spinning flask or a semi-continuous or perfusion or a continuous mode.
In one example, the bioreactor may agitate the cell culture for purposes of aeration using methods such as, for example, rocking, stirring, or channeling fluid or gas through the culture. Examples of such bioreactors include, for example, stirred tank fermentors or bioreactors agitated by rotating mixing devices, chemostats, bioreactors agitated by shaking devices, airlift fermentors/bioreactors, fluidized bed bioreactors, bioreactors employing wave induced agitation, centrifugal bioreactors or roller bottles.
In another example, the bioreactor may comprise means for quantification of biomass, such as, for example, by measuring the optical density of the culture medium. Suitable means for quantification of biomass include, for example, an optical sensor or a waveguide sensor or a Raman spectroscopy.
In yet another example, the bioreactor may include means for monitoring and/or measuring and/or adjusting one or more bioprocess parameters. As used herein, the term “bioprocess parameter” shall be taken to mean a chemical or physical property that may alter the growth rate of H. pylori . Suitable bioprocess parameters include, for example, temperature, pH, dissolved oxygen, carbon dioxide concentration, carbon source concentration, bile salt concentration, light, glucose concentration, pressure, concentration of an ionic species, concentration of a cellular metabolite, molarity, osmolality, glucose concentration, serum concentration and degree of agitation.
As will be apparent to the skilled artisan, a number of methods may be used to determine the growth rate of H. pylori.
Preferably, the bioreactor is a microreactor. The term “microreactor” as used herein refers to a bioreactor having a volume of less than 1000 mL or less than 900 mL or less than 800 mL or less than 700 mL or less than 600 mL or less than 500 mL or less than 400 mL or less than 300 mL or less than 200 mL or less than 100 mL or less than 90 mL or less 80 mL or less than 70 mL or less than 60 mL or less than 50 mL or less than 40 mL or less than 30 mL or less than 20 mL or less than 15 mL or less than 10 mL or less than 9 mL or less than 8 mL or less than 7 mL or less than 6 mL or less than 5 mL or less than 4 mL or less than 3 mL or less than 2 mL or less than 1 mL. Commercially available microreactors include, for example, the micro-Matrix (Applikon Biotechnology), the micro-flask (Applikon Biotechnology) and the advanced micro-scale bioreactor (Tap Biosystems).
Alternatively, the bioreactor is a large scale bioreactor. As used herein the term “large scale bioreactor” refers to a bioreactor used to produce a product for sale or for production of an intermediate of a product for sale. Preferably, a large scale bioreactor has an internal capacity of at least 1 L at least 2 L at least 3 L at least 4 L at least 5 L at least 6 L at least 7 L at least 8 L at least 9 L at least 10 L at least 20 L at least 50 L at least 100 L at least 200 L at least 300 L at least 400 L at least 500 L at least 600 L at least 700 L at least 800 L at least 900 L at least 1000 L in particular at least 2000 L at least 3000 L or at least 4000 L.
In a particularly preferred example, H. pylori is cultured from a frozen or unfrozen glycerol stock or other liquid stock or plate stock, employing H. pylori e.g., in a stock volume of about 3 mL that is then seeded into and cultured in a multichannel miniature bioreactor system or scalable stirred tank bioreactor e.g., a 2 L bench-top stirred tank bioreactor. A seed train may be employed, wherein an inoculum is prepared for a pilot-scale bioreactor. For example, a 400 L pilot-scale batch of H. pylori may be produced from one or two or three or four or five seed stages wherein each seed stage provides a 10-fold amplification of bacterial culture density as determined by OD at about 600 nm. In a similar scale-up process, an inoculum from a pilot-scale bioreactor is employed to inoculate a production-scale bioreactor. For example, batches of 2 L to 20 L of culture from a pilot-scale bioreactor process are combined until an appropriate volume is obtained for inoculation of a production-scale bioreactor. Incubation times for each stage vary in a range from about 16 hours to about 120 hours, including 16 hours to about 96 hours.
In another example, a seed culture is used to amplify cells and process volume to generate an inoculum for a pilot-scale bioreactor, which is then employed to inoculate medium in a production-scale bioreactor. For example, H. pylori cells (0.5 mL) stored frozen at −80° C. are revived by thawing at room temperature and 0.4 mL is transferred to 20 to 100 mL of medium, and the culture is incubated in a microaerobic environment at 37° C. for 16 to 96 hours until the optical density (measured at 600 nm) is in a range from about 0.4 to about 20. This seed culture is then used to inoculate a larger culture having a volume from about 200 mL to about 2000 mL which is then incubated under the same conditions to achieve the same cellular concentration as before. The larger culture is then used to inoculate a small bioreactor having an operating volume of 2 L (e.g., Biostat B, Sartorius-Stedim, Germany) or 10 L (e.g., Biostat C10, Sartorius-Stedim, Germany) or 16 L (e.g., New Brunswick Bioflo 510, Eppendorf, USA) or 50 L (e.g., Biostat D50, Sartorius-Stedim, Germany). The bioreactor is operated at 37° C. with pH, dissolved oxygen, and foam control. The pH is controlled at a set point in the range from pH6 to pH 8 such as by automatic addition of 10% (v/v) phosphoric acid or 10% (v/v) ammonia solution. Preferably, the bioreactor is sparged with a gas mixture containing nitrogen, carbon dioxide and a small proportion of oxygen (or compressed air) and a dissolved oxygen saturation is controlled e.g., in a range from 0.5% to 10% saturation, such as by varying stirrer speed and/or gas flow rate and/or vessel back pressure. Foam may be controlled by automatic addition of chemical antifoam, e.g., polypropylene glycol, added as required.
In an example of production-scale bioreactor process, a bioreactor having a volume from about 400 L to about 10,000 L is operated in a configuration that enables high yield of H. pylori cells. The system may be configured with an automated sterilization process and a series of re-sterilizable sample(s) and addition valves, to enable sampling and addition of reagent and product during fermentation. At inoculation, the inoculum is transferred aseptically to the production bioreactor. The bioreactor is operated at 37° C. with pH, dissolved oxygen and foam control, essentially as during the pilot-scale production process.
Fed-batch or “semi-batch” culture is particularly preferred for large-scale production of H. pylori . In fed-batch culture, one or more nutrients are fed to the bioreactor during cultivation and the cellular product remains in the bioreactor until the end of the run. In some cases, all the nutrients are fed into the bioreactor. Fed-batch culture permits better control of the nutrient concentrations in the culture liquid. Fed-batch H. pylori cultures are generally monitored for one or more of dissolved oxygen concentration, feed composition to increase cell number, feed rate to increase cell number, gas requirement required to increase cell number, and nutrient composition of medium required to increase cell number. This is because of the high nutrient demand of H. pylori . Optical density is monitored for comparative analysis of the media formulations and cell growth, such that a high optical density of cells is obtained in the shortest time frame. For example, a cell concentration above levels typically observed in batch culture may be obtained, such as greater than 20 optical density units at 600 nm and/or up to about 40 optical density units at 600 nm.
3. Inactivating and Killing H. pylori
H. pylori may be inactivated and/or killed by chemical means and/or physical means and/or genetic means. As used herein, the term “chemical means” refers to a method of inactivating and/or killing H. pylori by exposing H. pylori to a chemical agent. As used herein, the term “physical means” refers to a method of inactivating and/or killing H. pylori by exposing H. pylori to one or more physical treatments not involving the use of a chemical. As used herein, the term “genetic means” refers to a method of inactivating and/or killing H. pylori by modifying the genome of H. pylori.
Suitable chemical means for inactivating and/or killing H. pylori include the addition of one or more chemical agents such as formaldehyde and/or β-propiolactone and/or ethyleneimine and/or binary ethyleneimine and/or thimerosal and/or acid and/or alkali and/or one or more bactericidal agents and/or one or more reducing agents and/or a bile salt. Derivatives of these chemical agents known in the art may also be employed.
In one preferred example, H. pylori is inactivated and/or killed by exposure to formaldehyde at a concentration from about 0.01% to about 1% (w/w) or from about 0.01% to about 0.1% (w/w) or between about 0.025% and about 0.1% (w/w).
Alternatively, or in addition, H. pylori is inactivated and/or killed by exposure to polyethyleneimine functionalized zinc oxide nanoparticles as described, for example, by Chakraborti et al. 2012 Langmuir, 28:11142-11152.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to one or more bactericidal agent(s). For example, live and/or inactivated H. pylori can be subjected to treatment with one or more antibiotics selected from rifampin, amoxicillin, clarithromycin, rifamycin, rifaximin, the rifamycin derivative 3′-hydroxy-5′-(4-isobutyl-1-piperazinyl)benzoxazinorifamycin syn. KRM-1648 and/or the rifamycin derivative 3′-hydroxy-5′-(4-propyl-1-piperazinyl)benzoxazinorifamycin syn. KRM-1657.
Alternatively, or in addition, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to one or more acid(s) or to a low pH environment such as pH 3.0 or lower and/or to one or more base(s) or to high pH environment such as pH 9.0 or higher.
Alternatively, or in addition, inactivated and/or killed H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to one or more reducing agent(s) such as sodium bisulfite and/or one or more oxidative agents such as hydrogen peroxide.
Alternatively, or in addition, inactivated and/or killed H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to bile salts.
Suitable physical means for inactivating and/or killing H, pylori include exposure to visible light and/or ultraviolet light such as UV-C light and/or low-power laser photosensitizer and/or heat (e.g., dry heat or wet heat such as in steam) and/or elevated pressure and/or temperature shift and/or freeze-thaw and/or freeze-drying (lyophilization) and/or sonication.
Alternatively, or in addition H. pylori is inactivated and/or killed by exposure to visible light at wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm.
Alternatively, or in addition, H pylori is inactivated and/or killed by exposure to ultraviolet light, e.g., Hayes el al. 2006 , Appl. Environ. Microbiol. 72: 3763-3765.
For example, inactivated H. pylori as described according to any example hereof is prepared by exposing live H. pylori cells or strains to irradiation such as ultraviolet irradiation and/or by exposure to visible light such as wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm e.g., 405 nm violet light. In one example, inactivated H pylori as described according to any example hereof is prepared by a process comprising exposing live H pylori cells or strains to ultraviolet C (UVC) irradiation such as wavelength in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or to ultraviolet B (UVB) irradiation such as wavelength in a range from about 280 nm to about 315 nm and/or to ultraviolet A (UVA) irradiation such as wavelength in a range from about 315 nm to about 400 nm. Preferably, the live H. pylori is exposed to UVC light in a range from about 100 nm to about 280 nm such as about 257.3 nm and/or the live H. pylori is exposed to about 405 nm violet light to thereby inactivate H. pylori.
Alternatively, killed H. pylori as described according to any example hereof is prepared by a process comprising exposing live or inactivated H. pylori cells or strains to ultraviolet C (UV-C) irradiation such as wavelength in a range from about 100 nm to about 280 nm e.g., about 257.3 nm and/or to ultraviolet B (UV-B) irradiation such as wavelength in a range from about 280 nm to about 315 nm and/or to ultraviolet A (UV-A) irradiation such as wavelength in a range from about 315 nm to about 400 nm. Preferably, the live or inactivated H. pylori is exposed to UV-C light in a range from about 100 nm to about 280 nm such as about 257.3 nm. Alternatively, the live or inactivated is exposed to about 405 nm violet light to thereby kill H. pylori.
Alternatively, or in addition H. pylori is inactivated and/or killed by exposure to gamma irradiation.
Alternatively, or in addition, H. pylori is inactivated and/or killed by exposing live or inactivated H. pylori to low-power laser light in the presence of a photosensitiser as described, for example, by MILLSON et al. 1996 J. Med. Microbiology, 44:245-252. Alternatively, or in addition, H. pylori is inactivated and/or killed by heat treatment of cells.
For example, H. pylori may be inactivated by heat treatment wherein live H. pylori cells are exposed to heat treatment such as at temperatures in the range between about 40° C. to about 70° C. or more. Preferred heat treatment in this context may comprise exposure of live H. pylori cells to a temperature of about 60° C. or more for at least about 60 seconds, preferably at a temperature of about 60° C. or about 70° C. or about 80° C. or about 90° C. or about 100° C. or about 110° C. or about 120° C. or about 130° C. or about 140° C. or about 150° C., said temperature exposure being for a period of at least 3 minutes or at least 4 minutes or at least 5 minutes or at least 6 minutes or at least 7 minutes or at least 8 minutes or at least 9 minutes or at least 10 minutes or at least 20 minutes or at least 30 minutes or at least 40 minutes or at least 50 minutes or at least 1 hour or at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours or at least 7 hours or at least 8 hours or at least 9 hours or at least 10 hours or at least 11 hours or at least 12 hours or at least 13 hours or at least 14 hours or at least 15 hours or at least 16 hours or at least 17 hours or at least 18 hours or at least 19 hours or at least 20 hours or at least 21 hours or at least 22 hours or at least 23 hours or at least 1 day or at least 2 days or at least 3 days or at least 5 days or at least 5 days or at least 6 days or at least 7 days.
Alternatively, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to heat treatment such as by exposure to temperature of about 60° C. or more for at least about 60 seconds, preferably at a temperature of about 60° C. or about 70° C. or about 80° C. or about 90° C. or about 100° C. or about 110° C. or about 120° C. or about 130° C. or about 140° C. or about 150° C., said temperature exposure being for a period of at least 2 minutes or at least 3 minutes or at least 4 minutes or at least 5 minutes or at least 6 minutes or at least 7 minutes or at least 8 minutes or at least 9 minutes or at least 10 minutes or at least 20 minutes or at least 30 minutes or at least 40 minutes or at least 50 minutes or at least 1 hour or at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours or at least 7 hours or at least 8 hours or at least 9 hours or at least 10 hours or at least 11 hours or at least 12 hours or at least 13 hours or at least 14 hours or at least 15 hours or at least 16 hours or at least 17 hours or at least 18 hours or at least 19 hours or at least 20 hours or at least 21 hours or at least 22 hours or at least 23 hours or at least 1 day or at least 2 days or at least 3 days or at least 5 days or at least 5 days or at least 6 days or at least 7 days.
In one preferred example, live and/or inactivated H. pylori is killed by exposure to a single such elevated temperature or by exposure to at least two different elevated temperatures such as by exposure to a first temperature of about 70° C. followed exposure to a second temperature of about 90° C. or about 95° C. In one such preferred example, the live and/or inactivated H. pylori is killed by exposure to temperature of about 70° C. for about 10 minutes followed by exposure to temperature of about 90° C. or about 94° C. or about 95° C. for about 5 minutes.
Alternatively, or in addition, killed H. pylori as described according to any example hereof is prepared by exposing live and/or inactivated H. pylori cells or strains to elevated temperatures in the presence of steam and elevated pressure, such as by autoclaving live and/or inactivated H. pylori cells or strains. For example, live and/or inactivated H. pylori is killed by autoclaving the bacterial cells or strains for about 15 minutes at about 121° C. and about 15 psi, or for about 3 minutes at about at 132° C. and about 30 psi.
In one preferred example, H. pylori is inactivated and/or killed by temperature shift such as exposure to a single such elevated temperature or by exposure to at least two different elevated temperatures such as by exposure to a first temperature of about 70° C., followed exposure to a second temperature of about 90° C. or about 94° C. or about 95° C.
Alternatively, or in addition, H. pylori is inactivated and/or killed exposure of cells to one or more freeze-thaw cycles e.g., by exposure to 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 freeze-thaw cycles. Exemplary freeze-thaw cycles comprise freezing H. pylori in a dry ice/ethanol bath and then thawing the material at 37° C.
Alternatively, or in addition, H. pylori is inactivated and/or killed by freeze-drying cells.
Alternatively, or in addition, H. pylori is inactivated and/or killed by sonicating the cells. For example, killed H. pylori as described according to any example hereof is prepared by sonication e.g., at ultrasonic frequencies such as about 20 kHz or more of live and/or inactivated H. pylori.
Preferably, the inactivated and/or killed H. pylori as described according to any example hereof is prepared by first by exposing live H. pylori cells or strains to irradiation such as gamma irradiation and/or ultraviolet irradiation such as UV-C light and/or by exposure to visible light such as wavelengths ranging from about 375 nm to about 500 nm or in a range from about 400 nm to about 420 nm, to thereby inactivate H. pylori and then exposing the inactivated H. pylori cells or strains to heat treatment as described according to any example hereof to thereby kill the inactivated H. pylori or render the inactivated H. pylori irreversibly metabolically inactive.
For example, the inactivated H. pylori is then exposed to temperature of about 60° C. or more for at least about 60 seconds, preferably at a temperature of about 60° C. or about 70° C. or about 80° C. or about 90° C. or about 100° C. or about 110° C. or about 120° C. or about 130° C. or about 140° C. or about 150° C., said temperature exposure being for a period of at least 2 minutes or at least 3 minutes or at least 4 minutes or at least 5 minutes or at least 6 minutes or at least 7 minutes or at least 8 minutes or at least 9 minutes or at least 10 minutes or at least 20 minutes or at least 30 minutes or at least 40 minutes or at least 50 minutes or at least 1 hour or at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours or at least 7 hours or at least 8 hours or at least 9 hours or at least 10 hours or at least 11 hours or at least 12 hours or at least 13 hours or at least 14 hours or at least 15 hours or at least 16 hours or at least 17 hours or at least 18 hours or at least 19 hours or at least 20 hours or at least 21 hours or at least 22 hours or at least 23 hours or at least 1 day or at least 2 days or at least 3 days or at least 5 days or at least 5 days or at least 6 days or at least 7 days. In one such example, the inactivated H. pylori is exposed to a single such elevated temperature or to at least two different elevated temperatures such as by exposure to a first temperature of about 70° C. e.g., for about 10 minutes, followed by exposure to a second temperature of about 90° C. or about 95° C. e.g., for about 5 minutes.
In one preferred example, the killed H. pylori as described according to any example hereof is prepared by first by exposing live H. pylori cells or strains to ultraviolet irradiation such as UVC light e.g., at about as 257.3 nm to thereby inactivate H. pylori and then exposing the inactivated H. pylori cells or strains to heat treatment as described according to any example hereof to thereby kill the inactivated H. pylori or render the inactivated H. pylori irreversibly metabolically inactive.
Accordingly, in one preferred example, the composition according to any example hereof comprises H. pylori that has been subjected to a process for inactivating H. pylori by irradiation and a process for the killing the inactivated H. pylori by heat treatment.
Alternatively, or in addition, H. pylori as described according to any example hereof is inactivated and/or killed by exposing live or inactivated H. pylori to anaerobic conditions e.g., by changing the atmosphere in which H. pylori is cultured from microaerobic to anaerobic environment for example to mimic the in vivo atmospheric conditions during the washout of H. pylori from the stomach to the lower gut (e.g., small and/or large intestine). For example, live (such as freshly grown) H. pylori is inactivated by exposing (e.g., by growing or incubating) the bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 73 hours or at least about 96 hours or at least about 120 hours. In one such example, the live H. pylori cells are inactivated by exposing the cells to anaerobic conditions and by heat treatment of the cells.
In another example, live or inactivated H. pylori as described according to any example hereof is killed by exposing (e.g., by incubation) the live or inactivated bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 73 hours or at least about 96 hours or at least about 120 hours.
In one preferred example, the composition according to any example hereof comprises H. pylori that has been subjected to a process for inactivating H. pylori by exposing (e.g., by growing or incubating) the bacterial cells to anaerobic conditions for about 1 day to about 5 days or more, including for at least about 24 hours, or for at least about 48 hours or at least about 73 hours or at least about 96 hours or at least about 120 hours, and a process for the killing the inactivated H. pylori by heat treatment of the cells.
Suitable genetic means for producing inactivated H. pylori as described according to any example hereof comprises mutagenesis of live H. pylori cells or strains to modify one or more genes the expression of which is/are required for efficient colonization and/or maintenance of H pylori in the stomach and intestinal mucosa of human subject. For example, such genes may be deleted by recombination or modified by insertion of a transposon or other genetic element, or they may be inactivated by chemical mutagenesis. Such means are described in the art.
Inactivation and/or killing may be performed on H. pylori cells that are in a liquid, semisolid or solid form. In one example, H. pylori cultivated in a liquid may be inactivated and/or killed during a logarithmic phase of growth i.e., wherein cell numbers are increasing exponentially in culture or stationary phase of growth i.e., wherein viable cells in culture are post-logarithmic and not increasing in number.
In a particularly preferred example, a pilot-scale culture or other large-scale culture e.g., greater than 2 L or greater than 5 L or greater than 10 L or about 100 L to about 400 L volume including 100 L or 150 L or 200 L or 250 L or 300 L or 350 L or 400 L, or larger volume culture, is treated in a steam-in-place bioreactor or sterilisable-in-place bioreactor e.g., having the same operating system as a pilot-scale reactor described herein. In such bioreactors, the inactivation and/or killing process utilizes high temperature and high pressure to generate steam which is applied to the cells once they have achieved a desired cell density, to thereby inactivate and/or kill the cells
In another example, a culture in a fed-batch process is subjected to ultraviolet light e.g., UV-C irradiation, at an irradiance of greater than 100 Joules per OD unit at 600 nm, and the cells are then heat-treated at a temperature in a range from 60° C. to about 120° C. including 121° C. for a time in a range from about 15 minutes to about 6 hours.
The present invention also provides a master cell bank comprising the treated H. pylori of the present invention prepared as described herein. For example, a master cell bank may comprise aliquots of the treated H. pylori cells e.g., 100 or 200 or 300 or 400 or 500 vials comprising the cellular product. Preferably, a master cell bank is stored frozen e.g., at −80° C.
4. Harvesting Treated H. pylori Cells
Methods for harvesting microorganisms are well known in the art and are described, for example, by Ausubel et al. (In: Current Protocols in Molecular Biology. Wiley Interscience, ISBN 047 150338, 1987) or Sambrook et al. (In: Molecular Cloning: Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratories, New York, Third Edition 2001). As used herein, the term “harvesting” refers to a collection of H. pylori from medium upon, or in which, a population of H pylori has been cultivated. Suitable methods include, for example, centrifugation e.g. ultracentrifugation, or by filtration, e.g. ultrafiltration or microfiltration or deep filtration.
H pylori cells are generally harvested after inactivation and/or killing.
In a preferred example, treated cells are recovered from culture e.g., a bioreactor, by employing continuous centrifugation such as at a centrifugal force in a range from about 5,000×g to about 20,000×g. Preferably, the harvested cells are washed using a formulation buffer e.g., a phosphate-buffered saline or other pharmaceutically-acceptable excipient or diluent. The wash solution may be supplemented with dextran or an encapsulation formulations.
The cellular product is then packaged ready for storage or use. Preferably, the cells are lyophilized or spray-dried to generate a solid product suitable for long term storage.
Packs comprise one or more specifications of cellular product e.g., cell concentration, buffer composition, liquid formulation, dry formulation, pack size, etc.
5. Determining or Identifying Inactivated and/or Killed H. pylori
A method to measure utility of H. pylori or cell thereof in the compositions and/or methods as described in any example hereof includes any method that measures the ability of H. pylori or cell thereof to replicate and/or colonize a gastric mucosa of a mammal and/or any method that measures the ability of H. pylori or cell thereof to adhere to the gastric mucosa or epithelial cells thereof and/or any method that measure viability and/or metabolic activity of H. pylori e.g., following stress and/or inactivation and/or killing treatment of H, pylori as described according to any example hereof.
In one example, the ability of a H. pylori or cell thereof to replicate and colonize the gastric mucosa in a mammal is determined by quantification of viable bacteria such as by colony count. See e.g., Drumm and Sheman 1991 , J. Med. Microbiol 35:197-202.
For example, 0.5 ml of a sample measuring cell equivalent of optical density of about 0.2 to about 5.0 or more at 660 nm stored H. pylori bacteria which has been cultured, and subjected to stress and/or inactivation and/or killing treatment e.g., as described according to any example hereof, is resuspended in a 250 ml Erlenmeyer flask containing 11 ml of fresh medium of Brucella Broth (e.g., Gibco Laboratories, Madison, Wis., USA) supplemented with 10% fetal bovine serum (e.g., Boknek Laboratories, Ontario, Canada), or other media suitable for growth of H. pylori e.g., as described according to any example hereof. If required, the culture medium is supplemented with trimethoprim (e.g., Sigma Chemicals, St. Louis, Mo., USA) 5 mg/L and/or vancomycin (e.g., Sigma) 10 mg/L. The flask is closed with a loosely fitted screw cap and placed inside an incubation jar which is then evacuated and flushed through with a gas mixture containing CO 2 10%, O 2 5%, N 2 85%, and incubated at 37° C. on a rotary shaker and incubated at 37° C. with shaking at 100 rpm. After about 24 hours, approximately 1 ml of bacterial culture is transferred to fresh medium of Brucella Broth and re-cultured. Absence of viable and replicating H. pylori is confirmed by subculture of broth on supplemented Brucella agar plates and inspection of bacterial morphology by phase contract microscopy. See e.g., Drumm and Sherman, 1989 , J. Clin Microbiol, 27:1655-1656.
Alternatively, or in addition, quantification of viable and replicating H. pylori bacteria is performed in the broth cultures by serial dilution and sequential measurements of optical density of cultures at 600 nm and/or by colony counts e.g., after incubation for 6, 12, 18, 24, 30 and 36 hours. For example, if present, cell counts of viable and replicating H. pylori bacteria are determined by inoculating serial dilutions of cultures in triplicates onto Brucella agar and incubating plates for 5 days at 37° C. in microaerobic conditions. Viable and replicating H. pylori produce smooth, translucent colonies on Brucella agar. To improve the accuracy of viable counts (cfu), 4 mg/L tetrazolium salts are added to the Brucella agar prior to inoculation of the agar with the bacterial cultures. After incubation for 5 days at 37° C. in microaerobic conditions, viable and replicating H. pylori cells produce red colonies on this medium. Absence of H. pylori colonies as described herein confirms that H. pylori is inactivated and/or killed and is incapable of replicating and colonising the gastric mucosa.
In another example, inactivated and/or killed H. pylori may be confirmed by any assay measuring metabolic activity of H. pylori such as, for example, urease production and/or ATP consumption.
In one preferred example, Rapid Urease Test, also known as Campylobacter -like organism (CLO) test, is used to detect presence of H. pylori which is partially or fully metabolically active based on the ability of H. pylori to secrete a urease enzyme which catalyzes the conversion of urea to ammonia and CO 2 . According to this example, aliquots of about 1 μl to about 100 μl, of samples measuring cell equivalent of optical density of about 0.2 to about 5.0 or more at 660 nm of stored H. pylori bacteria cultured, and subjected to stress and/or inactivation and/or killing treatment e.g., as described according to any example hereof, or aliquots of about 1 μl to 100 μl of bacterial cells cultured in any suitable medium e.g., Brucella Broth medium as described above, are added to sterile Eppendorf tubes containing freshly prepared urease indicator reagent to a total volume of 200 μl. For example, a urease indicator reagent containing about 2% (w/v) to about 5% (w/v) urea, and at least one pH indicator such as phenol red, bromothymol blue, bromocresol purple, and methyl red at a concentration of about 0.1% (w/v) or about 0.05% (w/v) in 0.01 M phosphate-buffered saline (PBS), may be used. If required, the pH of each urease indicator reagent formulation may be adjusted to the lower end of the known pH range for each indicator with the use of 0.1 N or 1.0 N HCl; For example, the indicator phenol red has a pH range of 6.6 to 8.0 and a urease indicator reagent formulation comprising phenol red may be adjusted to pH 6.6; the indicator bromothymol blue has a pH range of 6.0 to 7.6 and a urease indicator reagent formulation comprising bromothymol blue may be adjusted to pH 6.0; the indicator the indicator bromocresol purple has a pH range of 5.2 to 6.8 and a urease indicator reagent formulation comprising bromocresol purple may be adjusted to pH 5.2; the indicator the indicator Methyl red has a pH range of 4.8 to 6.2 and a urease indicator reagent formulation comprising bromocresol purple may be adjusted to pH 4.8. Alternatively, the urease indicator reagent is prepared as described by Nedrud J G, Blanchard T G. Helicobacter animal models. In: Coligan J E, Bierer B, Margulies D H, Shevach E M, Strober W, Coico R, editors. Current Protocols in Immunology . Philadelphia: John Wiley and Sons; 2000. p. 19.8.1-26. Alternatively, the urease indicator reagent may be obtained commercially e.g., from ASAN pharm. Co., Seoul, Korea. The tubes are then vortexes and incubated at room temperature. After 4 hours the tubes are centrifuged at RCF 6000 for 5 minutes and about 100 μl of the supernatant is transferred to a 96-well plate to be read spectrophotometrically at 550 nm. If required, Gastric mucosal tissue homogenates from mice uninfected with H. pylori e.g., prepared as described below may serve as negative control for the urease assay. Also, if required, a positive control containing known concentrations of cultured H. pylori such as wild type H. pylori capable of replicating and colonizing the mucosa may be used. Samples of H. pylori showing less than 5% urease activity as determined by the Rapid Urease Test indicate H. pylori which is inactivated and/or killed.
As will be apparent to the skilled artisan, a number of urease tests are commercially available, such as, for example, CLOtest (Kimberly-Clark), Hpfast (Sigma) and Pyloritek (Serim).
In another example, inactivation and/or killing of H. pylori is confirmed by performing an oxidase test. As used herein, the term “oxidase test” shall refer to an assay used to detects the presence of a cytochrome c oxidase using a redox indicator such as, for example, N,N,N,N-tetramethyl-p-phenylenediamine (TMPD) or N,N-dimethyl-p-phenylenediamine (DMPD). Suitable oxidase tests are described for example by Tsukita et al. 1999 J. Biochem. 1235:194-201 or Murray et al. (In: Manual of Clinical Microbiology, American Society for Microbiology, Washington D.C., Ninth Edition 2007).
In another example, inactivation and/or killing of H. pylori is confirmed by performing a catalase test. The term “catalase test” shall be taken to encompass any assay that determines the ability of H. pylori to liberate oxygen gas from hydrogen peroxide by catalase degradation. Suitable catalase test will be apparent to the skilled artisan.
In yet another example, inactivation and/or killing of H. pylori is confirmed by performing a motility assay as described, for example, by Worku et al. 1999 Microbiology 145: 2803-2811.
In another example, the ability of a H. pylori or cell thereof to replicate and/or colonize the gastric mucosa of a mammal is determined using in vitro assay of H. pylori adherence to human gastric tissue. See e.g., Hemalatha et al. 1991 , J. Med. Microbiol 35:197-202; Falk et al., 1993 , Proc. Natl. acad. Sci. USA. 90:2035-2039; Hsieh et al. 2012 Helicobacter 17:466-477.
In another example, the ability of a H. pylori or cell thereof to replicate and colonize the gastric mucosa in a mammal is determined by analysis of in vivo stomach colonization infected animals e.g., mice. For example, H. pylori bacteria which has been cultured, and subjected to stress and/or inactivation and/or killing treatment e.g., as described according to any example hereof, is harvested and resuspended in sterile saline. As a positive control a culture of H. pylori known to be capable of replicating and colonizing the gastric mucosa of a mammal and which has not been the subjected to stressing and/or inactivation and/or killing treatment prior to inoculation challenge described below, is used. Suitable H. pylori capable of replicating and colonizing the gastric mucosa are known in the art. Briefly, a flask containing BHI broth plus 4% fetal calf serum (FCS) is inoculate with an aliquot of a positive control H. pylori stock and allowed to incubate for 25 to 48 hours at 37° C. in an atmosphere of 10% CO 2 +5% O 2 , shaking at 125 rpm, to yield a pure culture of H. pylori bacteria having the expected morphology to be used for infection. For challenge inoculum an optical density of a 1:10 dilution of the sterile saline suspension comprising the H. pylori bacteria which has been cultured, and subjected to stress and/or inactivation and/or killing treatment is read at 660 nm, and inoculum samples generating a reading of between 0.07 and 0.002 are used for inoculation of mice.
Alternatively, samples for inoculation comprising an amount of H. pylori bacteria which has been cultured and subjected to stress and/or inactivation and/or killing treatment in a range equivalent to between about 1×10 7 to 2×10 10 cells/ml or CFU/ml as determined e.g., by a haemocytometer, are used. For positive control H. pylori , an inoculum of about 1×10 8 cells is used. Six to 8 weeks old C57BL/6 mice (from Charles River Laboratories (Wilmington, Mass.) and/or BALB/c (from Charles River Laboratories (Wilmington, Mass.) are challenges orally with a dosage comprising an amount of bacteria in a range corresponding between 10 8 to 10 10 cells, preferably 10 9 cells of H. pylori bacteria subjected to stressing and/or inactivation and/or killing treatment and an inoculum of about 1×10 8 cells comprising the control H. pylori , by gavage twice within a 1-week period, preferably at least one day separating each challenge.
Alternatively, mice are challenged by intragastric immunization wherein about 0.25 ml or about 0.5 ml or about 1 ml volumes comprising inoculum dosages as above are delivered into the stomach of lightly etherized mice by intubation through polyethylene tubing attached to a hypodermic syringe. If required, this procedure may be performed three times in a 5-day period, with 24 hours between dosing.
According to this example, for the purpose of analysing stomach colonization two weeks following challenge mice are sacrificed e.g., by CO 2 inhalation and stomachs and duodenum are removed for quantitative assessment of colonization. For example, the stomachs and duodenum are transferred to labelled sterile Petri plates containing 5-10 ml of sterile PBS, and are then transferred to a biosafety cabinet where the stomachs are opened by midline incision and the contents gently cleaned using sterile gauze. The antrum is visualized and aseptically dissected away from the rest of the stomach, which is discarded. The antral section is then diced, using sterilized single-edge razor blades, and the pieces placed in a pre-weighed 5 ml tube containing brain-heart infusion broth (BHI) media. If required, tubes containing antral sections are re-weighed to 0.001 g accuracy and placed in a biosafety cabinet. The sections may then be mechanically macerated e.g., using sterile plastic tissue homogenizers and serial 1:10, 1:100, and 1:1000 dilutions of the homogenates are made in BHI media. From each dilution tube a 100 μl aliquot is placed on a sterile BHI agar plate and a full plate spread is performed. For example, the media on which homogenates are plated contain BHI agar (Difco), 4% fetal bovine serum, bacitracin, nalidixic acid, amphoteracin B, and Campylobacter selective supplement (Oxoid, Lenexa, Kans.). Plates are placed in anaerobic jars containing BBL CampyPak Plus microaerophilic envelopes (Becton Dickinson, Franklin Lakes, N.J.; product #271045) and preferably incubated at 37° C. for 6-7 days. Growth control plates are included in each jar, inoculated with a freshly grown preparation of the positive control H. pylori supra. The limit of detection in this assay is approximately 500 H. pylori cells per gram of stomach tissue. Absence of H. pylori colonies indicates that the H. pylori is inactive and is unable to replicate and colonise the gastric mucosa. However, if colonies are observed on plates, colonies may be confirmed to be H. pylori by means as described in any example hereof e.g., using one urease activity assay and/or oxidase activity assay and/or catalase activity assay and/or by colony morphology.
In yet another example, the ability of a H. pylori or cell thereof to replicate and colonize the gastric mucosa in a mammal is determined by polymerase chain reaction (PCR) detection of colonization of H. pylori in conventional euthymic mice based on detection of the H. pylori 16S ribosomal gene sequence. See e.g. Smith et al., 1996, Clinic. Diagn. Lab. Immuno. 3:66-72. For example, H. pylori bacteria which has been cultured, and subjected to stress and/or inactivation and/or killing treatment e.g., as described according to any example hereof, is harvested and resuspended in sterile saline. If required, as a positive control a culture of H. pylori e.g., wild type (WT) H. pylori , known to be capable of replicating and colonizing the gastric mucosa of a mammal and which has not been the subjected to stressing and/or inactivation and/or killing treatment prior to inoculation challenge described below, is separately harvested and resuspended in sterile saline. Suitable H. pylori capable of replicating and colonizing the gastric mucosa are known in the art and are described herein. For challenge inoculum an optical density of a 1:10 dilution of the inoculum is read at 660 nm, and inoculum samples generating a reading of between 0.07 and 0.002 are used for inoculation of mice.
Alternatively, inoculum samples comprising an amount of bacteria in a range corresponding to between about 2×10 7 to 2×10 8 cells/ml or CFU/ml as determined for example by a haemocytometer, are used. Eight to 12 weeks old VAF and GF Swiss-Webster mice or VAF CD-1 mice (from Taconic Laboratories (Germantown, N.Y.)) and/or VAF-CD-1 mice (from Charles River Laboratories (Wilmington, Mass.) and/or C57BL/6 mice (from Charles River Laboratories (Wilmington, Mass.) and/or BALB/c (from Charles River Laboratories (Wilmington, Mass.) and/or SJL/J mice (from The Jackson Laboratory, Bar Harbor, Me., USA) are challenges orally with 0.5 ml of the H. pylori inoculum prepared as described above, by gavage twice within a 1-week period, preferably at least one day separating each challenge. All mice are housed in sterile microisolator cages with sterile water and mouse chow ad libitum. If required GF mice are maintained and manipulated using sterile GF procedure, in laminar flow hood with all surfaces sanitized, and cages for GF mice are autoclaved in sterile wrap, and water is also autoclaved and filter sterilized prior to use. To assess H. pylori colonisation of the gastric mucosa in challenged mice, about 1 to about 4 weeks post challenge, preferably about 4 weeks post challenge, mice are sacrificed e.g., by inhalation of CO 2 and stomachs are removed by aseptic techniques. Stomachs are then cut longitudinally, and the stomach contents are washed away by rinsing with sterile deionized H 2 O. The stomach mucosa is then separated from the stomach lining tissue by gently scraping the mucosa with sterile glass microscope slides. Mucosa samples are then placed in Tris-sodium chloride-EDTA (TNE) buffer and stored on ice or frozen until DNA extraction for PCR analysis. Methods for extracting DNA from the mucosa suspensions for PCR analysis are known in the art and may be readily employed. For example, DNA are extracted by centrifuging the stomach mucosa suspension in TNE buffer for 3 min at 12,000 rpm. The supernatant is then removed, and the cell pellet is resuspended in 570 ml of TNE containing 1% Triton X-100 (Sigma) and 0.5 mg of lysozyme (Sigma) per ml. Samples are then incubated at 37° C. for 30 min. Next, 1 mg of proteinase K (Boehringer GmbH, Mannheim, Germany) per ml is added, and the mixture is incubated at 65° C. for 2 hours or at 37° C. overnight. The digest is mixed with an equal volume of phenol-chloroform-isoamyl alcohol (25:24:1) and then centrifuged at 10,000 3 g for 6 min. The top aqueous layer is then removed, and a second extraction with phenol-chloroform-isoamyl alcohol is preferably performed. The aqueous layer is then mixed with an equal volume of chloroform-isoamyl alcohol (24:1) and processed as in the previous two extractions. DNA is then precipitated by adding a 1/10 volume of 3 M sodium acetate and 2 volumes of absolute ethanol and placing on dry ice for 20 min. DNA is pelleted by centrifugation as described above and rinsed with 70% ethanol. The pellet is preferably dried e.g., by speed vacuum and resuspended in 100 ml of 0.13 TE (13 TE is 10 mM Tris [pH 7.4], 0.1 mM EDTA). Samples are stored at 4° C. until the PCR is run.
PCR primers used for amplification of a DNA sequence of H. pylori encoding the 16S rRNA which are used include the upstream primer (HP forward) set forth in SEQ ID NO: 1 had having the sequence 5′-TTG GAG GGC TTA GTC TCT-3′, and the downstream primer (HP reverse) set forth in SEQ ID NO: 2 and having the sequence 5′-AAG ATT GGC TCC ACT TCA CA-3′. The primers set forth in SEQ ID NO: 1 and SEQ ID NO: 2 are designed to 459 bp PCR product spanning bases 793 to 1252 of the H. pylori DNA sequence. SEQ ID NO: 1 and SEQ ID NO: 2 primers are designed based on a region of homology for six isolates of H. pylori listed in gene bank accession numbers U00679, U01328, U01329, U01330, U01331, and U01332 and which differs from the sequences listed for H. felis (gene bank accession number M57398), H. muridarum (gene bank accession number M80205), and Campylobacter sp. (gene bank accession number L04315). Accordingly use of these primers avoids cross-reactivity with closely related bacteria.
If required, internal PCT control DNA templates can also be constructed for use in the PCR reaction. See e.g, Smith et al, 1996 supra. For example, the 495-bp PCR product amplified from a WT H. pylori using the primers set forth in SEQ ID NO 1 and SEQ ID NO: 2 as described according to any example hereof, is closed into a multi-copy plasmid. Subsequently, an internal restriction fragment of 237 bp, conveniently flanked by SM sites, is deleted from within the cloned H. pylori DNA to create a template with perfect homology to the HP primers but from which a much shorter sequence would be amplified with those primers. The 459-bp PCR amplified H. pylori DNA fragment was purified by using a GENECLEAN® kit (Bio 101, Inc., La Jolla, Calif.) 15 and ligated with T4 DNA ligase (GIBCO BRL, Gaithersburg, Md.) into the EcoRV site of plasmid pBLUESCRIPT II SKI® (Stratagene Co., La Jolla, Calif.), which confers ampicillin resistance and encodes the lacZa peptide. The recombinant plasmids are transformed into Escherichia coli DH5a (GIBCO BRL). Ampicillin-resistant transformants are selected on Luria broth plates containing X-Gal (5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside), and plasmids carrying inserted DNA are identified as giving white colonies. Plasmids are extracted from selected colonies with the Qiagen plasmid purification kit (Qiagen Inc., Chatsworth, Calif.) and cut with Styl restriction endonuclease (New England BioLabs, Beverly, Mass.), which removes an internal 237-bp DNA fragment from the H. pylori DNA insertion. The remaining DNA is recircularized with T4 DNA ligase and transformed into strain DH5a, and colonies are selected as ampicillin resistant. Transformants yield the desired 222-bp fragment when amplified in PCRs with the HP primers set forth in SEQ ID NO: 1 and SEQ ID NO: 2. One transformant may be selected was selected, and plasmid DNA is extracted for use as the internal PCT control template.
PCT analysis is conducted by preparing master reaction mixtures, under sterile conditions. Each master mixture is made in in a 1.5-ml microcentrifuge tube and contains reactants for 45 sample reactions. To each master mix there is added 826.9 ml of deionized H 2 O, 112.5 ml of 103 Taq buffer (Stratagene), 45 ml of deoxynucleoside triphosphate (5 mM), 22.5 ml of each primer of SEQ ID NO: 1 or SEQ ID N: 2 (25 to 50 mM), and 5.6 ml of Taq polymerase (5 U/ml; Stratagene). If required, the master mixtures are aliquoted at 23 ml per reaction into 200-ml PCR tubes. The volume of each reaction mixture for PCR is brought up to 25 ml by adding 2 ml of DNA templates extracted mouse mucosal DNA extracted above, typically comprising an amount of 2 mg of extracted DNA. If required, PCR reaction tubes are briefly centrifuged to mix reactants. PCR reaction mixtures containing the mucosal DNA extracted from mice challenged with H. pylori subject to stressing and/or inactivation and/or killing treatment and, if required, from negative control mice challenges with WT H. pylori are cycled in Perkin-Elmer 9600 System thermal cycler (Perkin-Elmer, Norwalk, Conn.). DNA is amplified for 35 cycles of 15 s at 94° C., 30 s at 55° C., and 1 min at 72° C., with a final elongation cycle at 72° C. for 10 min. Positive and negative control reactions may be perfumed performed with each amplification. If required, control templates in each PCR run may be used which consist of deionized H 2 O, H. pylori DNA corresponding to 1, 10, and 100 cells, and mouse mucosal tissue DNA (2 mg). The PCR products are analyzed by 2% agarose gel electrophoresis with ethidium bromide incorporation and visualized under UV light. Detection of a PCR product is scored as colonization, while absence of a PCR product is scored as no-colonization, and provides a positive confirmation that the H. pylori is inactive and is unable to replicate and colonise the gastric mucosa of a mammal.
Other methods for measuring the utility of H. pylori or cell thereof in the compositions and/or methods as described in any example hereof will be apparent to the skilled artisan and are encompassed by the present invention.
6. Formulations
Inactivated and/or Killed H. pylori or Cell Lysates Thereof May be Formulated for Oral Administration to a Human or Mammal.
In one example, inactivated and/or killed H. pylori or a cell lysate thereof is encapsulated. As used herein, the term “encapsulated” shall be taken to mean that the inactivated and/or killed H. pylori or cell lysate is enclosed within a degradable barrier.
For example, the degradable barrier may degrade at a predetermined location in gastrointestinal tract.
In one example the composition is in the form of a tablet or a capsule.
In another example, composition of the present invention is lyophilised. In another example, the composition of the present invention is a powder.
Compositions of the present invention may be formulated as a foodstuff or dietary supplement. As used herein, the term “foodstuff” refers to any food product or beverage and the term “dietary supplement” refers to a product intended to supplement the diet of a human or mammal that comprises a vitamins and/or a mineral and/or a herb or other botanical and/or an acid.
In one example, the foodstuff or dietary supplement may be a ready-to-drink product. As used herein, the term “ready-to-drink” shall be taken to mean that the product is in a form suitable for oral administration without additional preparation. Suitable ready-to-drink products may include, for example, carbonated water, flavoured water, carbonated flavoured water, drinks containing juice (juice derived from any fruit or any combination of fruits, juice derived from any vegetable or any combination of vegetables), milk drinks obtained from animals, milk drinks derived from soy, rice, coconut or other plant material, yoghurt drinks, sports drinks, energy drinks, coffee, decaffeinated coffee, tea, tea derived from fruit products, tea derived from herb products, decaffeinated tea and liquid meal replacements. In one example, the ready-to-drink product may comprise filtered water, skim milk powder, cane sugar, wheat maltodextrin, soy protein, vegetable oils, starch, inulin, corn syrup solids, fructose, cereals, flavour, calcium, phosphorus, fermented red rice, vitamin C, Niacin, vitamin A, vitamin B12, vitamin B6, vitamin B2, vitamin BI, folate and salt. In another example, the ready-to-drink product may comprise include carbonated water, corn syrup, caramel color, caffeine, phosphoric acid, coca extract, lime extract, vanilla and glycerine. In yet another example, the ready-to-drink product may comprise carbonated water, sucrose, glucose, sodium citrate taurine, glucuronolactone, caffeine, inositol, niacinamide and vitamin B 12.
In another example, the foodstuff or dietary supplement may be a ready-to-eat product. As used herein, the term “ready-to-eat” shall be taken to mean that the product is in a form suitable for oral administration without additional preparation. Suitable ready-to-eat products may include, for example, a meal replacement bar, a protein bar, snack food and confectionary product. In one example, the ready-to-eat product may comprise wholegrain cereals, glucose, sugar, vegetable oil, maize starch, humectants, rice flour, oat flour, skim milk powder and honey.
In yet another example, the foodstuff or dietary supplement may require suspension and/or reconstitution in a liquid or diluent prior to administration. For example, the foodstuff or dietary supplement may be a liquid or liquid concentrate or powder.
In one example, the foodstuff or dietary supplement may be an infant formula or follow-on formula or infant formula for special dietary use or pre-term formula. As used herein, the term “infant formula” shall refer to a breast milk substitute which satisfies the nutritional requirement of infants aged up to about four to about six months. In one example, the infant formula may have an energy content of no less than about 2500 kJ/L and no more than about 3150 kJ/L. In one example, the infant formula may comprise an amount of protein between 0.45 g per 100 kJ and 0.7 g per 100 kJ, an amount fat between 1.05 g per 100 kJ and 1.5 g per 100 kJ. In another example, the infant formula may comprise less than 0.05 mg of aluminium per 100 mL. As used herein, the term “follow-on formula” shall refer to a breast milk substitute or a replacement for infant formula which constitutes the principal liquid source of nourishment for infants aged from about six months. For example, infant follow-on formula may have an energy content of no less than about 2500 kJ/L and no more than about 3550 kJ/L. In one example, the infant formula may comprise an amount of protein between 0.45 g per 100 kJ and 1.3 g per 100 kJ, an amount fat between 1.05 g per 100 kJ and 1.5 g per 100 kJ. In another example, the infant formula may comprise less than 0.05 mg of aluminium per 100 mL. The term “infant formula product for special dietary use” as used herein shall be taken to mean an infant formula product formulated to satisfy particular needs of infants with a particular metabolic and/or immunological and/or renal and/or hepatic and/or malabsorptive condition. For example, infant formula products for specific dietary use may have an energy content of no less than about 2500 kJ/L and no more than about 3550 kJ/L. In one example, the infant formula may comprise an amount of protein between 0.45 g per 100 kJ and 1.3 g per 100 kJ, an amount fat between 0.93 g per 100 kJ and 1.5 g per 100 kJ. In another example, the infant formula may comprise less than 0.05 mg of aluminium per 100 mL. The term “pre-term formula” shall be construed broadly to mean an infant formula product specifically formulated to satisfy particular needs of an infant born prior to 36 weeks of gestation. Preferably, pre-term formula may comprise an amount of protein between 0.45 g per 100 kJ and 1.3 g per 100 kJ, an amount fat between 0.93 g per 100 kJ and 1.5 g per 100 kJ. In another example, the infant formula may comprise less than 0.02 mg of aluminium per 100 mL.
Compositions of the invention may comprise one or more prebiotics or paraprobiotics or probiotics e.g., as a food, beverage, dietary supplement or animal feed.
The term “probiotic” used herein shall be taken to mean live microorganisms, which when administered in an adequate amount confers a health benefit on the host. Suitable probiotics include, for example, Aspergillus niger, Aspergillus oryzae, Bacillus coagulans, Bacillus lentus, Bacillus licheniformis, Bacillus pumilus, Bacillus subtilis, Bacteroides amylophilus, Bacteroides capillosus, Bacteroides ruminocola, Bacteroides suis, Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium bifidum, Bifidobacterium infantis, Bifidobacterium longum, Bifidobacterium thermophilum, Enterococcus cremoris, Enterococcus diacetylactis, Enterococcus faecium, Enterococcus intermedius, Enterococcus lactis, Enterococcus thermophilus, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus cellobiosus, Lactobacillus curvatus, Lactobacillus delbruekii, Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus lactis, Lactobacillus plantarum, Lactobacillus reuteri, Leuconostoc mesenteroides, Pediococcus acidilacticii, Pediococcus pentosaceus, Propionibacterium freudenreichii, Propionibacterium shermanii, Saccharomyces cerevisiae.
The term “paraprobiotic” has been coined to refer to those products comprising killed or inactivated microbes which may positively affect host health (Taverniti V and Guglielmetti S, 2011 , Genes Nutr. 6(3): 261-274).
As used herein, the term “prebiotic” shall be taken to mean a non-digestible food ingredient that beneficially affects a host by selectively stimulating growth and/or activity of one or more microorganisms in the gut. Suitable prebiotics include, for example, fructooligosaccharides, transgalactooligosaccharides, inulins, acacia gum, xylooligosaccharides, isomaltooligosaccharides, lactulose and soy oligosaccharides.
7. Administration
Compositions of the present invention may be formulated for daily or periodic administration. For example, the composition may be administered daily for a period of at least about 1 week or at least about 2 weeks or at least about 3 weeks or at least about 4 weeks or at least about 5 weeks or at least about 6 weeks or at least about 7 weeks or at least about 8 weeks or at least about 9 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks or at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months, or at least about one year or more than one year. Preferably, the composition is administered, over a period of at least about 13 weeks or at least about 3 months.
In another example, the composition may be administered periodically, such as, for example, every second day or every third day or every fourth day or every fifth day or every sixth day or every second week for a period of at least about 1 week or at least about 2 weeks or at least about 3 weeks or at least about 4 weeks or at least about 5 weeks or at least about 6 weeks or at least about 7 weeks or at least about 8 weeks or at least about 9 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks or at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks. In yet another example, the composition may be administered intermittently. For example, the composition may be administered for an administration period at least about 1 week or at least about 2 weeks or at least about 3 weeks or at least about 4 weeks or at least about 5 weeks or at least about 6 weeks or at least about 7 weeks or at least about 8 weeks or at least about 9 weeks or at least about 10 weeks or at least about 11 weeks or at least about 12 weeks or at least about 13 weeks or at least about 14 weeks or at least about 15 weeks or at least about 16 weeks or at least about 17 weeks or at least about 18 weeks or at least about 19 weeks or at least about 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months, followed by a period of discontinuance, followed by an administration period at least 1 week or at least 2 weeks or at least 3 weeks or at least 4 weeks or at least 5 weeks or at least 6 weeks or at least 7 weeks or at least 8 weeks or at least 9 weeks or at least 10 weeks or at least 11 weeks or at least 12 weeks or at least 13 weeks or at least 14 weeks or at least 15 weeks or at least 16 weeks or at least 17 weeks or at least 18 weeks or at least 19 weeks or at least 20 weeks or at least about 21 weeks or at least about 22 weeks or at least about 23 weeks or at least about 24 weeks or at least about 25 weeks, or at least about 6 months. Preferably, wherein the composition is administered for a period of at least about 13 weeks or at least about 3 months, followed by a period of discontinuance, and then followed by an administration period of at least about 13 weeks or at least about 3 months. In another example, the composition may be administered for an administration period of at least 1 or 2 or 3 or 4 of 5 or 6 or 7 or 8 or 9 or 10 or 15 or 20 or 25 or 30 or 35 or 40 years.
In one example, compositions may be formulated as a daily dosage comprising H. pylori or cell lysate thereof in an amount corresponding to about 10 6 cells or about 10 7 cells or about 10 8 cells or about 10 9 cells or about 10 10 cells or about 10 11 cells or about 10 12 or between about 10 6 cells to about 10 12 cells or between about 10 7 cells to about 10 11 cells or between about 10 8 cells to about 10 10 cells or between about 10 9 cells to about 10 10 cells. As will be apparent to the skilled artisan, single or multiple dosage units may be administered to make up the daily dosage.
In another example, compositions may be formulated for administration to infants aged between 0 to about 5 years, or between 0 to about 4 years, or between 0 to about 3 years, or between 0 to about 2 years, or between 0 to about 1 year. In one example, the composition may be formulated for administration to infants aged between 0 to about 2 years. In another example, the composition may be formulated for administration to infants of an age between about 4 months and about 12 months. In another example, the composition may be formulated for administration to infants less than about 6 months of age.
In yet another example, compositions may be formulated for administration to children older than about 5 years of age and/or to adolescents and/or to adults.
In a further example, a composition of the invention according to any example hereof is a cosmetic or a nutraceutical formulation such as a food stuff, tablet, capsule, or liquid drink, for administration to a subject not suffering from a medical condition referred to herein such as allergy or one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma or in need of prevention of such medical condition. For example, a cosmetic or a nutraceutical formulation of the present invention will promote a general sense of wellbeing and/or boost the immune system and/or provide balance to the immune system of a subject not in need of therapy or prophylaxis from any medical condition(s).
In one example, the present invention provides a method of cosmetic or nutraceutical use comprising administering a composition comprising inactivated and/or killed H. pylori or a cell lysate thereof according to any example hereof to a subject not suffering from a medical condition referred to herein such as allergy or one or more of allergic eczema, urticaria, hives, rhinitis, wheezing, airway resistance, airway restriction, lung inflammation, food allergy, or asthma or in need of prevention of such medical condition. In one such example, the method of the present invention promotes a general sense of wellbeing and/or boost the immune system and/or provide balance to the immune system of a subject not in need of therapy or prophylaxis from any medical condition(s).
The present invention is described further in the following non-limiting examples:
Example 1
Treatment to Inactivate and/or Kill H. pylori Cells—Method I
This example demonstrates the utility of ultraviolet irradiation, and optional additional freeze-thawing, for inactivating and/or killing H. pylori cells.
Cells of Helicobacter pylori strain OND79 deposited with the National Measurement Institute (NMI) of Australia under Accession No. V13/023374 were obtained by growth on Columbia agar (CBA) plates comprising Columbia agar base (Product Code CM0311, Thermo Fisher Scientific, Oxoid Ltd) and 7% (v/v) sterile defibrinated horse blood for 24 hours and harvesting cells by resuspension of grown cells in saline solution [0.9% (w/v) sodium chloride] and then centrifugation, according to standard procedures. The cells were then resuspended in saline solution, and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 1 optical density (OD) unit per ml. Equal volumes (1 ml) of resuspended cells were plated onto CBA plates comprising 7% (v/v) sterile defibrinated horse blood. The plates were incubated for 24 hours at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 .
Plate samples were then subjected to ultraviolet irradiation using ultraviolet C (UV-C) light (wavelength between 200 and 290 nm) in Bio-Link BLX crosslinker UV chamber (Vilber Lourmat, France) at an irradiance of 4 Joules/cm 2 or 12 Joules/OD 600 of plated cells. For example, a plate of 9 cm diameter may be irradiated by exposure to about 240 Joules UV-C. Irradiated bacteria were then collected from the plates, resuspended in the saline solution and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 20 optical density (OD) unit per ml.
As untreated control, OND79 H. pylori cells which were cultured, harvested and plated as described above but which were not irradiated using UV-C were also collected and resuspended in a saline solution and the concentration of untreated resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 20 optical density (OD) unit per ml.
Aliquots of the irradiated cells were assayed directly to determine cell replication ability and urease activity, or alternatively, frozen at −20° C. and then thawed, prior to cellular replication and urease testing being performed.
To test for an ability of irradiated cells, optionally subjected to irradiation and freeze-thawing, to replicate, the bacterial suspensions were serially-diluted in saline, plated onto CBA plates, and the plates incubated for 3 days at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 . Cell counts were then determined for the various dilutions tested.
In two independent experiments, no colony forming units were identified for suspensions in a concentration range corresponding to a measured absorbance at 600 nm wavelength of 0.056-3.6 OD units per ml. The same results were obtained for cells receiving only UV-C as for cells receiving UV-C and a cycle of freeze-thawing.
Urease activities of the treated cells were determined by standard assay of resuspended cells. Briefly, 25 μl of urease buffer comprising 0.1 M citrate, 2 g/l urea and phenol red 0.01% was added to an equal volume of treated cell suspension, and the pH of the mixture was determined at room temperature over a period of 30 mins. In this assay, a change in assay sample colour from yellow to red is indicative of an increase in pH due to breakdown of urea and production of ammonia. Data obtained for two independent experiments indicates that UV-C irradiated cells had residual urease activity relative to untreated cells, estimated to be less than 10% of the urease activity of untreated H. pylori cells e.g., prior to UV irradiation.
Consistent with the reduced urease activity of the irradiated cells, SDS/PAGE of extracts from H. pylori cells exposed to UV-C irradiation demonstrate that the irradiated cells undergo protein degradation, and aggregation of proteins into high molecular weight complexes, compared to untreated cells (data not shown). In a UV-C dosage range of 1-4 J/cm 2 , the level of such degradation and aggregation is dose-dependent i.e., a higher UV-C dose e.g., 2 J/cm 2 or 4 J/cm 2 , produces increased degradation and aggregation (data not shown).
Collectively, the data indicate that UV-C irradiation and optionally, additional freeze-thawing of H. pylori , provides an effective means for inactivating and/or killing H. pylori.
Example 2
Treatment to Inactivate and/or Kill H. pylori Cells—Method II
This example demonstrates the utility of ultraviolet irradiation or oxygen restriction, and optional additional heat treatment following ultraviolet irradiation or oxygen restriction and/or by heat treatment alone, for inactivating and/or killing H. pylori cells.
Cells of H. pylori strain OND79, or cells of H. pylori strain OND86 deposited with the National Measurement Institute (NMI) of Australia under Accession No. V14/013016 (described in Example 15), or cells of H. pylori strain J99 were grown on Columbia agar (CBA) plates comprising Columbia agar base (Product Code CM0311, Thermo Fisher Scientific, Oxoid Ltd) and 7% (v/v) sterile defibrinated horse blood for 24 hours and harvesting cells by resuspension of grown cells in saline solution [0.9% (w/v) sodium chloride] and then centrifugation, according to standard procedures. The cells were then resuspended in saline solution, and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 1 optical density (OD) unit per ml. Equal volumes (1 ml) of resuspended cells were plated onto CBA plates comprising 7% (v/v) sterile defibrinated horse blood. The plates were incubated at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 for 24 hours if cells were then subjected UV irradiation or, alternatively, for 18 hours if the cells were then subjected to oxygen starvation.
After 24 hours at microaerobic conditions plate samples were then subjected to ultraviolet irradiation using UV-C light, and the irradiated bacteria were then collected from the plates, resuspended in the saline solution and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 20 optical density (OD) unit per ml, as described in Example 1. Optionally, the resuspended cells were then subjected to heat treatment by exposure to a first elevated temperature of about at 70° C. for 10 minutes immediately followed by exposure to a second elevated temperature of about 94° C. or 95° C. for 5 minutes at normal atmosphere conditions.
Alternatively, after 18 hours incubation in microaerobic conditions as described above, cultured H. pylori cells were then subjected to oxygen restriction treatment depleting the H. pylori cultures of oxygen by transferring the plates to plates hermetically sealed jars containing gas sachets (AnaeroGen, AN0025A, ThermoScientific) to generate anaerobic conditions. Plates were then incubated at under anaerobic conditions at 37° C. for periods of 24 h or 48 hours or 72 hours. The bacteria which were subjected to oxygen starvation treatment were then collected from the plates, resuspended in the saline solution and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 20 optical density (OD) unit per ml. Optionally, the resuspended cells were then subjected to heat treatment by exposure to a first elevated temperature of about at 70° C. for 10 minutes immediately followed by exposure to a second elevated temperature of about 94° C. or 95° C. for 5 minutes at normal atmosphere conditions.
Alternatively, H. pylori cells which had been cultured on CBA plates for 24 hours at microaerobic conditions as described above were resuspended in the saline solution and the concentration adjusted to a measured absorbance at 600 nm wavelength of 20 optical density (OD) unit per ml. The resuspended cells were then subjected to inactivation and/or killing by heat treatment alone by exposing the cells to a first elevated temperature of about 70° C. for 10 minutes and then to a second elevated temperature of about 94° C. or 95° C. for 5 minutes at normal atmosphere conditions.
To test for the ability of H. pylori treated cells to replicate, bacterial suspensions of live untreated H. pylori OND86 cells (live control) and bacterial suspensions of H. pylori OND86 cells that were subjected to ultraviolet irradiation using UV-C light (UV) and optionally further subjected to heat treatment (UV+heat) or which were subjected to oxygen starvation treatment for 48 hours (O 2 restriction) and optionally further subjected to heat treatment (O 2 restriction+heat), were serially-diluted in saline, plated onto CBA plates, and the plates incubated for 3 days at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 . Cell counts were then determined for the various dilutions. Results obtained from two independent experiments are shown in FIG. 2 . The results indicate that treatment of H. pylori cells by UV irradiation, UV irradiation and heat treatment, oxygen restriction and heat treatment abolished the ability of treated H. pylori cells to replicate and form colonies. Although in one independent experiment where H. pylori cells were subjected to oxygen restriction for 48 hours without further heat treatment resulted in H. pylori colonies on CBA plates, the ability of the treated cells to replicate was substantially reduced relative to untreated live H. pylori . In a further independent experiment, H. pylori cells which were subjected to heat treatment alone to inactivate and/or kill the cells consistently generated no colonies on CBA plates (data not shown), indicating that exposure to heat treatment alone e.g., as described herein also abrogates replication capabilities of H. pylori cells.
To test for the effect of various oxygen restriction treatment periods on the ability of H. pylori cells to replicate, H. pylori OND86 cells which were subjected to oxygen restriction for periods of 24 hours, or 48 hours or 72 hours without additional heat treatment, were collected from the plates after incubation under anaerobic conditions as described above, resuspended in the saline solution and the concentration of resuspended cells was adjusted to a measured absorbance at 600 nm wavelength of 1 optical density (OD) unit per ml, and seeded onto fresh CBA plates after serial 10-fold dilution. Plates were then incubated for 3 days at 37° C. in a microaerobic environment containing 5% (v/v) CO 2 and less than 5% (v/v) O 2 . H. pylori were able to form colonies after 24 hours of oxygen restriction treatment, however, following 48 hours of oxygen restriction H. pylori cultures demonstrated limited growth on CBA plates, and after 72 hours of oxygen restriction no H. pylori colonies were formed on the CBA plates (results not shown). These results indicate that treatment of live H. pylori cells by oxygen restriction for a period of about 48 hour or more e.g., between 48 hours to 72 hours or more is effective in reducing and/or preventing replication ability of H. pylori thereby inactivating and/or killing H. pylori cells.
Urease activities of bacterial suspensions of live untreated H. pylori OND86 cells (live control) and bacterial suspensions of H. pylori OND86 cells that were subjected to ultraviolet irradiation using UV-C light (UV) and optionally further subjected to heat treatment (UV+heat) or which were subjected to oxygen starvation treatment for 48 hours (O 2 restriction) were and optionally further subjected to heat treatment (O 2 restriction+heat), were determined by the standard urease test. Briefly, 25 μl of urease buffer comprising 0.1 M citrate, 2 g/l urea and phenol red 0.01% was added to an equal volume of live untreated cells and treated cell suspension, and the pH of the mixture was determined spectrophotometrically at 560 nm after incubation of the cells at room temperature over a period of 5 mins. In this assay, a qualitative urease activity was determined as a measure of metabolic activity of the treated cells. H. pylori urease enzyme activity was evaluated based on a change in assay sample colour from yellow to red is indicative of an increase in pH due to breakdown of urea and production of ammonia.
Results of the qualitative urease activity are provided in Table 1 below.
TABLE 1
Qualitative Urease Activity.
Treatment of H.
pylori OND86 cells
Urease activity
No treatment
++
(live control cells)
UV irradiation
−/+
(UV)
UV irradiation +
−
heat
O 2 restriction
++
O 2 restriction +
−
heat
Enzymatic activity was evaluated based on the change of colour from yellow to red measured at 560 nm after incubation of the cells at room temperature over a period of 5 mins. Four qualitative levels were used; negative, −; weak, −/+; moderate, +, strong ++. Treatment of H. pylori OND86 cells are as indicated above.
In a second, independent, experiment urease activity of bacterial suspensions of live untreated H. pylori OND86 cells (live control) and bacterial suspensions of treated H. pylori OND86 cells was performed by the urease test as above, except that urease enzyme activity was measured at 560 nm after 1 minute incubation of the cells at room temperature. The urease activity of the live untreated bacteria was set at 100%, and the relative urease activity reading output for treated i.e., inactivated and/or killed bacteria was calculated as a percentage of the urease activity measured for the live untreated H. pylori . In this experiment suspensions H. pylori OND86 cells were also tested for urease activity following heat treatment alone i.e., by exposure to elevated temperature of about 70° C. for 10 minutes and then about 94° C. or 95° C. for 5 minutes as described above. The results of the urease activity of H. pylori cells subjected to heat treatment alone (Heat), UV-C irradiation (UV) and optionally further heat treatment (UV+heat), oxygen starvation for 48 hours (O 2 res) and optionally further heat treatment (O 2 res+heat), relative to the urease activity readout of the live untreated cells is shown in FIG. 3 .
The results shown in FIG. 2 and the urease activity results shown in Table 1 and FIG. 3 indicate that although treatment to inactivate and/or kill H. pylori e.g., by way of UV treatment alone, UV plus heat treatment, oxygen starvation plus heat, or by heat treatment alone, can abrogate replication ability of H. pylori , the treated cells display residual metabolic activity as determined by the urease test.
To further investigate the metabolic activity of treated H. pylori cells, the ability of treated H. pylori cells to respire was evaluated by measuring the membrane redox potential of treated cells by flow cytometry using the BacLight™ RedoxSensor™ CTC (product catalogue No. B34956) from Invitrogen (Molecular Probes™ Invitrogen detection technologies) according to manufacturer's instructions. Live cells of H. pylori OND86 strain were subjected to heat treatment alone, oxygen starvation for 48 hours and optionally further heat treatment, or UV-C irradiation and optionally further heat treatment as described above to inactivate and/or kill the cells. Approximately the equivalent of 10 7 cells per tune were incubated with 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) in the dark for 6 hours and then fixed by addition of 4% formaldehyde according to manufacturer's instructions. The ratio of the redox potential obtained by FACS analysis for live untreated H. pylori cells relative or cells which were treated by oxygen starvation or UV-C irradiation relative to the redox potential obtained for the live or treated cells after heat treatment was calculated to normalize the redox potential of the different inactivation and/or killing treatment regimes. Without being bound by any specific theory of mode of action, the present inventors speculated that heat treatment of H. pylori cells as described herein may lead to destruction of the majority of metabolic activity in treated cells and may further result in alteration of cell shape and/or cell aggregation patterns. Accordingly, to take into account variations in FACS cells sorting arising from differences in cell shape or cell aggregation that may arise due to heat treatment of cells, normalization of the redox potential for cells following heat treatment was performed. The results are shown in FIG. 4 . The results show that both live and UV-C treated cells were metabolically active and were respiring before heat treatment (ratio of 0.85 and 1.1, respectively), whereas treatment of live H. pylori cells by exposure to oxygen restriction led to a ratio of 0.1 indicating that treatment of cells by oxygen starvation significantly attenuated metabolic activity of H. pylori . Treatment by oxygen restriction resulted in 8.5-fold decrease in the redox potential ratio compared to redox potential ration obtained for live cells, but UV-C irradiation had little effect on the redox potential ratio relative to live cells.
Collectively, the herein data indicate that UV-C irradiation and optionally heat treatment of cells, or oxygen starvation and optionally heat treatment of cells, provide an effective means for inactivating and/or killing H. pylori.
Example 3
H. pylori Improves Outcomes of Allergic Asthma in the OVA Model of Allergic Airways Disease
Adult C57BL/6 mice (6 to 8 weeks) were infected with wild-type H. pylori (WT), wild-type H, pylori expressing the asthma inducing antigen (OVA), or treated H. pylori (KD), or left uninfected. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. Eight (8) weeks later, an allergic asthma phenotype was induced by sensitized mice with OVA/alum i.p. (day 0 and 14) and then challenged with OVA aerosol for 5 days from day 21-25. Control mice were uninfected, sensitised and challenged (positive) or only sensitised (negative). On day 26 mice received methacholine (MCh) challenge at increasing doses and airway resistance in the lungs was measured. FIG. 5 shows that H. pylori protected mice from induction of an allergic asthma phenotype.
Example 4
H. pylori Reduces Total Cell Count and Eosinophilia in the OVA Model of Allergic Airways Disease
Adult C57BL/6 mice (6 to 8 weeks) were infected orally by gavage with wild-type H. pylori (WT), wild-type H. pylori -expressing the asthma inducing antigen (HpOVA), treated H. pylori (KD) or left uninfected. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. Eight (8) weeks later, an allergic asthma phenotype was induced by sensitised mice with OVA/alum i.p. (day 0 and 14) and then challenged with OVA aerosol for 5 days from day 21-25. Control mice were uninfected, sensitised and challenged (positive) or only sensitised (negative). On day 26 mice were sacrificed and bronchioalveolar lung fluid collected. Total cell counts (Panel A) and eosinophil counts (Panel B) in the BALF were enumerated and the average number of eosinophils recruited to the lung is represented from 10 mice per group. FIG. 6 shows that H. pylori reduces total cell count and eosinophilia.
Example 5
H. pylori Decreases OVA-Specific IgE and OVA-Specific IgG Response in the OVA Model of Allergic Airways Disease
Adult C57BL/6 mice were infected orally by gavage with wild-type H. pylori (WT), wild-type H. pylori -expressing the asthma inducing antigen (HpOVA), treated H. pylori (KD) or left uninfected. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. Eight (8) weeks later, mice were sensitized with 20 μg OVA/1 mg alum i.p. (day 0 and 14) and then challenged intranasally with 2 μg OVA in saline for 4 days from day 21-24. Control mice were uninfected, sensitised and challenged (positive) or only sensitised (negative). On day 25 mice were bled and OVA-specific IgE (Panel A) and IgG (Panel B) antibodies were measured from serum, diluted 1:60 and 1:6000 respectively, by ELISA. Results are expressed as the individual and average absorbance at OD 405 nm. FIG. 7 shows that H. pylori decreases OVA-specific IgE (Panel A) and OVA-specific IgG (Panel B) response in the ova model of allergic airways disease.
Example 6
H. pylori Reduces IL-13
Adult C57BL/6 mice were infected orally by gavage with H. pylori (WT), treated bacteria (KD) or left uninfected. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. As a comparator, H. pylori strain 10700 was also tested. 8 weeks later, mice were sensitized with 20 μg OVA/1 mg alum i.p. (day 0 and 14) and then challenged intranasally with 2 μg OVA in saline for 4 days from day 21-24. Control mice were uninfected, sensitised and challenged (positive) or only sensitised (negative). On day 25 bronchioalveolar lung fluid (BALF) was collected from the lungs of anaesthetised mice. IL-13 was measured from undiluted BALF using cytokine bead array and expressed as the average of 10 mice per group in pg/ml. FIG. 8 shows that IL-13 is reduced in the lungs of H. pylori -infected mice in the allergic asthma model.
Example 7
H. pylori Reduces OVA-Specific CD8 T Cells
Adult C57BL/6 mice were infected orally by gavage with ˜1×10 9 CFU H. pylori (WT) or left uninfected for 8 months then received 2 doses of 20 μg OVA/2 mg alum on day 0 and 28. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. One day prior to OVA/alum challenge, mice received 5×10 4 MACS purified CD8 OT-I cells i.v. Spleens were harvested on day 35 and single cell suspension of spleen cells was stimulated with SIINFEKL peptide for 4 hours in presence of BrefA. Intracellular cytokine staining was performed to measure IFNγ secretion by FACS. CD8 OT-I cells were identified by CD45.1 expression. Colonization results from the stomach showed that all WT infected mice were colonized. H. pylori reduces the OVA-specific CD8 T cell response and impairs function of OVA-specific CD8 T cells. FIG. 9 shows the decreased number (panel A) and function (panel B) of OVA-specific CD8 T cells in H. pylori infected mice compared to control mice after OVA/alum challenge.
Example 8
H. pylori Decreases Antigen-Specific IgG
Adult C57BL/6 mice were infected orally by gavage with ˜1×10 9 CFU H. pylori (WT) or left uninfected for 8 weeks then injected i.p. with 20 μg OVA/alum. 14 days later serum was collected and OVA-specific IgG determined by ELISA.
In some mice a secondary i.p. dose of OVA/alum was administered at day 14. No differences in OVA-specific IgG titres was observed at day 21 (7 days after boost). Mice are able to overcome H. pylori -mediated immune suppression in the presence of sufficient immunological stimulus. FIG. 10 (panel A) shows decreased antigen-specific IgG in H. pylori -infected compared to control mice after primary OVA/alum challenge. FIG. 10 (panel B) shows antigen specific IgG response 7 days after secondary challenge.
Example 9
H. pylori Reduces Responsiveness of CD4 and CD8 T Cells
Adult C57BL/6 mice were infected orally by gavage with ˜1×10 9 CFU H. pylori (WT) or left uninfected. 7 months after challenge spleen cells were isolated and single suspensions of cells stimulated with PMA/ionomycin for 4 hours in the presence of Brefeldin A. Numbers of IFNγ CD4+ and CD8+ T cells were assessed using intracellular cytokine staining and FACS. FIG. 11 shows the reduced responsiveness of CD4 and CD8 T cells from H. pylori infected mice to non-specific stimulus.
Example 10
Effect of H. pylori Colonisation in the Neonatal Allergic Asthma Model
5-day old female C57BL/6 mice (n=5-10) were fed ˜10 9 CFU live H. pylori for 5 consecutive days or left uninfected. 8 weeks later, mice were sensitized with 2 doses of 50 μg OVA/1 mg alum i.p. (day 0 and 14) and then challenged with OVA aerosol for 5 days from day 21-25. Control mice were uninfected, sensitised and challenged (positive control, i.e., untreated allergic mice) or only sensitised (negative control, i.e., untreated healthy mice). On day 26 mice received metacholine (MCh) at increasing doses and airway hyperresponsiveness (AHR) of lung tissue was measured and bronchio-alveolar lung fluid (BALF) collected.
FIG. 12 , in panel A, shows the results in which AHR results are expressed as the average cmH2o.s/ml per group of mice. Statistical significance was determined using a one-sided student's t-test assuming a normal Gaussian distribution where p<0.5. The non-parametric Wilcoxon rank test that is suitable for non Gaussian distribution showed statistical significance at the three highest concentration of MCh. In FIG. 12 , panel B, total cell infiltrate from the lungs was determine and is expressed at the average number of live total cells from BALF per group of mice. Bars represent standard deviation from the mean. Statistical significance was determined using a one-sided student's t-test assuming a normal Gaussian distribution where p<0.5.
The results herein demonstrate that H. pylori reduces symptoms of allergic asthma. FIG. 12 (panel A) shows that airway resistance increased in allergic adult mice not infected with live H. pylori , whereas mice challenged with live H. pylori from day 5 exhibited comparable airway resistance to that of non-allergic mice. FIG. 12 (panel B) further demonstrates that H. pylori colonization prevents cellular infiltration in the lungs after allergen challenge and that the total cell count was similar to non-allergic control mice. Accordingly, live H. pylori protects neonatal mice from developing allergic asthma in response to allergen exposure later in life and reduces cellular infiltrate in the lungs.
FIG. 12 demonstrates that H. pylori colonization e.g., in neonates improves outcomes of allergic airways disease and reduces risk of developing allergic airway disease, for example as shown using the neonatal allergic asthma model described herein.
Example 11
Effect of H. pylori on Immunological Outcome in a Neonatal Allergic Asthma Model
The present inventors inter alia conduct a side-by-side comparison of the effects on protection against allergic disease, such as allergic airway disease, achieved by administration of live colonizing bacteria or repeated oral administration of treated H. pylori to neonatal mice. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. Briefly, 5-day old C57BL/6 mice (n=10) were fed ˜10 9 CFU live H. pylori for 5 consecutive days or treated bacteria (for 3 days per week, for 10 weeks) or left untreated. 8 weeks later, mice were sensitized with 2 doses of 50 μg OVA/1 mg alum i.p. (day 0 and 14) and then challenged with OVA aerosol for 5 days from day 21-25. Control mice were uninfected, sensitised and challenged (positive control i.e., untreated allergic mice) or only sensitised (negative control i.e., untreated healthy mice). On day 26 mice were sacrificed and serum and bronchio-alveolar lung fluid (BALF) collected. Total cell infiltrate per group of mice in the lungs was determined and is expressed as the individual and average number of live total cells from BALF. As shown in FIG. 13 administration of either treated or live H. pylori effectively reduced cellular infiltration in the lungs of H. pylori treated mice (Panel A). In addition, allergen (OVA)-specific IgE antibodies were measured by standard ELISA methods from serum diluted 1:60. Antibody titres were expressed as the individual and average absorbance at OD 405 nm. As shown in FIG. 13 (panel B), administration of either treated H. pylori or live H. pylori also reduced allergic allergen-specific IgE antibodies in H. pylori treated subjects. *Statistical significance was determined using a one-sided student's t-test assuming a normal Gaussian distribution where p<0.5. Collectively, the data illustrated in panels (A) and (B) of FIG. 13 demonstrate that administration of treated i.e., inactivated and/or killed (or live) H. pylori is effective in reducing allergic inflammation and/or allergic immune responses.
Inflammatory cytokines, IL-5 and IL-13 were measured from undiluted BALF using a cytokine bead array kit and results are expressed as the average concentration of cytokine per group in pg/ml and shown in FIG. 13 (panels C and D). The results shown in FIG. 13 (panels C and D) demonstrate that administration of treated (or live) H. pylori was successful in reducing production of cytokine mediators and biological markers of asthma and allergic respiratory disease, IL-5 and IL-13, in the lungs.
In another experiment as shown in FIG. 14 , the present inventors also demonstrated that adult and neonatal mice administered with treated (i.e., inactivated and/or killed) or live H. pylori had reduced allergic airway resistance response. Lung airway hyperresponsivness (AHR) was measured using 5-day old female C57BL/6 mice (n=5-10) as well as adult C57BL/6 mice (6-8 weeks, n=10) essentially as described in Example 10. In brief, neonatal and adult mice were fed ˜10 9 CFU/dose of treated bacteria, 3 times per week for 8 weeks or fed ˜10 9 CFU/dose of live freshly cultured bacteria for 6 consecutive days. Treated H. pylori were inactivated and/or killed as described in Example 1. On day 0 and 14, all mice received intraperitoneal OVA/alum. The allergic asthma phenotype was induced with 1% OVA aerosol for 5 consecutive days from day 21. Control mice were uninfected, sensitised and challenged (positive control, i.e., untreated allergic mice) or only sensitised (negative control, i.e., untreated healthy mice). In other words, positive and negative controls did not receive bacteria. On day 26 mice received metacholine (MCh) at increasing doses and airway hyperresponsiveness (AHR) of lung tissue in response to MCh challenge was measured, and mice were sacrificed.
As shown in FIG. 14 , panel A, allergic adult mice which did not receive H. pylori (positive control) showed elevated airway resistance after allergen challenge compared with airway resistance of adult mice which received a formulation of treated H. pylori or live H. pylori . As shown in FIG. 14 , panels B and C, allergic neonatal mice which did not receive H. pylori (positive control) showed elevated airway resistance after allergen challenge compared with airway resistance of neonatal mice which received a formulation of treated H. pylori or live H. pylori . The results shown in panels A, B and C of FIG. 14 represent three independent experiments, and demonstrate that H. pylori can reduce or attenuate allergic response e.g., of allergic airway disease such as asthma in response to allergen in both adults and neonatal subjects. These results further demonstrate that this effect occurs equally as well when either live H. pylori or inactivated and/or killed H pylori are used. In other words, the results demonstrate that inactivated and/or killed H. pylori bacteria are as effective as live H. pylori bacteria in reducing or attenuate allergic response e.g., of allergic airway disease such as asthma in response to allergen in both adults and neonatal subjects, thereby protecting subjects from allergic disease such as allergic as asthma.
Example 12
Inactivated and/or Killed H. pylori Cells do not have the Same Colonization Capability of Live H. pylori Cells
This example demonstrates the utility of treatment to inactivate and/or kill H. pylori cells in reducing the efficacy of H. pylori cells in colonizing the gastric mucosa of allergic subjects in adult allergic asthma model.
Adult C57BL/6 mice (6 to 8 weeks, n=10) were infected orally by gavage with ˜1×10 9 CFU of OND79 H. pylori (WT) or treated H. pylori three (3) times per week for a duration of eight (8) weeks. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. At the end of the 8 weeks period, mice were sensitized with 2 doses of 50 μg OVA/1 mg alum i.p. (day 0 and 14) and then challenged with OVA aerosol for 5 days from day 31-35. Control mice were uninfected, sensitised and challenged (positive) or only sensitised (negative). Mice were sacrificed on day 36 and stomach tissue harvested. Stomachs were dissected along the greater curvature and residual food removed by gently washing with PBS. Opened stomachs were placed in 500 μl PBS and homogenized with a 5 mm stainless steel bead for 30 seconds at a frequency of 30 (Qiagen TissueLyser II). Samples were further homogenized for 2 min at a frequency of 10. Serial dilutions of homogenates were plated on BHI agar plates supplemented with amphotericin B (8 μg/ml), trimethoprim (5 μg/ml) and vancomycin (6 μg/ml), nalidixic acid (10 μg/ml), polymyxin B (10 μg/ml) and bacitracin (200 μg/ml). Plates were placed in gas-controlled chambers containing two Campygen kit gas packs (Product Code CN0025A, Thermo Fisher Scientific, Oxoid Ltd) and incubated at 37° C. Bacterial growth was determined 5-7 days post plating. Results of H. pylori colonization of the gastric mucosa in infected mice are shown in FIG. 15 and are expressed as the number of colony forming units (CFU) per stomach per mouse.
The results in FIG. 15 demonstrate that although live untreated H. pylori were able to colonize gastric mucosa of allergic mice, treated H. pylori did not colonize gastric mucosa of infected allergic adult mice. This demonstrates that treated H. pylori cells do not have the same colonization capability as a live bacterium having the same genotype.
The inventors also tested the effect of H. pylori colonisation in the neonatal allergic asthma model. In particular, the inventors have repeated the above experiment with the exception that instead of using adult mice, 5-day old female C57BL/6 mice (n=5-10) were infected orally by gavage with ˜1×10 9 CFU of OND79 H. pylori (WT) or treated H. pylori three (3) times per week for a duration of eight (8) weeks. The H. pylori inocula comprised 0.2 ml of a suspension of H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed as described in Example 1. At the end of the 8 weeks period mice were treated as above. The results obtained show that colonization with live untreated (WT) H. pylori was achieved in 1 out of 5 neonatal mice at the commencement of the study. On the other hand, no colonization was observed for any mice infected with treated H. pylori as demonstrated by lack of any detectable H. pylor CFU on BHI agar plates plated with undiluted and serial dilutions of 1:10 and 1:100 of homogenised stomach samples (data not shown). These results confirm that treated H. pylori cells which are inactivated and/or killed also have reduced colonization capability relative to a live H. pylori having the same genotype in neonatal subjects.
Example 13
Inactivated and/or Killed H. pylori Cells are Unable to Colonize the Gastric Mucosa
This example supports the findings in Example 12 and further demonstrates that treatment to inactivate and/or kill H. pylori cells abrogates ability of H. pylori cells in colonizing the gastric mucosa of adult mice.
Adult C57BL/6 mice (6 to 8 weeks, n=5) were repeatedly inoculated orally by gavage with approximately 1×10 9 CFU of treated OND79 H. pylori 3 times per week for 2 weeks. The H. pylori inocula comprised 0.2 ml of a suspension of treated H. pylori strain OND79 cells in saline solution adjusted to a measured absorbance at 600 nm wavelength of 20 OD unit per ml. Treated H. pylori were inactivated and/or killed by subjecting live H. pylori cells to ultraviolet irradiation using UV-C light and optionally further subjected to heat treatment, or by subjecting live H. pylori cells to oxygen starvation treatment for 48 hours and optionally further subjected to heat treatment, as described in Example 2.
To determine the level of colonization, stomach tissue was harvested from animals 2 weeks after final oral inoculation. Stomachs were dissected along the greater curvature and residual food removed by gently washing with PBS. Opened stomachs were placed in 500 μl PBS and homogenized with a 5 mm stainless steel bead for 30 seconds at a frequency of 30 (Qiagen TissueLyser II). Samples were further homogenized for 2 min at a frequency of 10. Serial dilutions of homogenates were plated on H. pylori selective (DENT's supplement, nalidixic acid and bacitracin) F12 agar medium plates. Plates were incubated as described above and after three days of incubation at 37° C. (Anoxomat, 83% N 2 , 7% CO 2 , 6% O 2 and 4% H 2 ) and single colonies were counted to determine bacterial growth 5-7 days post plating.
Efficacy of infection and colonization of the mouse gastric mucosa for treated H. pylori was assessed based on the number of colony forming units (CFU) per stomach. The results are shown in FIG. 16 and demonstrate that treatment of H. pylori by UV-C irradiation and optionally heat treatment, or by oxygen starvation for 48 hours and optionally further heat treatment abolishes the colonization capability of H. pylori . These results confirm the findings in Example 12 and further demonstrate that it is possible to inactivate and/or kill H. pylori and prevent colonization by H. pylori by more than merely one means of treating live H. pylori cells.
Example 14
Immunological Efficacy of Inactivated and/or Killed H. pylori in Neonatal Allergic is not Strain Specific
This example demonstrates a side-by-side comparison of the effects on immunological protection against allergic disease, achieved by administration of treated i.e., inactivated and/or killed H. pylori strains from different geographical origins and belonging to genetically removed ancestral populations of H. pylori . There are identified 6 distinct ancestral populations of H. pylori identified by multi-locus sequence typing analysis and have been named ancestral European 1, ancestral European 2, ancestral East Asia, ancestral Africa1, ancestral Africa2, and ancestral Sahul. H. pylori strain OND79 used in this example is a European strain, and H. pylori strain J99 used in this example is an African strain.
Live H. pylori OND79 cells or H. pylori J99 cells were inactivated and/or killed by UV-C irradiation treatment as described Examples 1 and 2. Treated H. pylori OND79 cells and treated H. pylori J99 cells were administered to 5-day old C57BL/6 mice, and mice were sensitized and challenged with allergen (OVA) by following the same method described in Example 11. Control mice were uninfected, sensitised and challenged (positive control i.e., untreated allergic mice) or only sensitised (negative control i.e., untreated healthy mice). On day 26 mice were sacrificed and serum and collected. In addition, allergen (OVA)-specific IgE and IgG antibodies were measured by standard ELISA methods from serum diluted 1:60. Antibody titres were expressed as the individual and average absorbance at OD405 nm.
As shown in FIG. 17 administration of either UV-C treated H. pylori OND79 cells or UV-C treated H. pylori J99 cells reduced allergic allergen-specific IgE and IgG antibodies in mice. These results demonstrate that efficacy conferred by administering treated i.e., inactivated and/or killed H. pylori (such as UV-C treated H. pylori ) in allergic asthma mouse model is not strain specific. This is because treated i.e., inactivated and/or killed H. pylori of different origins were effective in reducing allergic immune responses to allergen relative to untreated allergic mice.
Example 15
Production of a H. pylori Strain Passaged in a Human Host for Use in the Compositions and/or Methods of the Invention
This example demonstrates the production and characterization of a passaged strain or derivative of H. pylori strain OND79 obtained after passaging in a human host. The resulting passaged or derivative strain of H. pylori is suitable for treatment to inactivate and/or kill the cells and use in the compositions and/or methods of the invention.
Expansion of H. pylori OND79 for Administration to Human
H. pylori OND79 strain was expanded for human administration by the following method. Specifically, commercially available PyloriAgar (PA) plates (from BioMerieux, France) were purchased for culture of H. pylori OND79 strain to prepare an inoculum of the OND79 strain for human challenge. To this effect, a glycerol stock vial of H. pylori OND79 strain (Heart Infusion [HI] broth containing 20% (v/v) glycerol and 10% (v/v) of H. pylori OND79 cells) which had been stored at −80° C., was thawed and inoculated onto 5 PA agar plates. The bacteria-inoculated plates were subjected to an atmosphere evacuation/replacement cycle using an Anoxomat (ANCTS2, Mart Microbiology, Drachten, The Netherlands) to generate micro-aerobic conditions (approximately 83% N 2 , 7% CO 2 , 6% O 2 and 4% H 2 ) and were incubated at 37° C. for 72 h. The total plate content was then expanded onto new PA plates. Bacteria were harvested and suspended in 1 ml of sterile saline solution (0.9%). Six plates were then inoculated with 100 μl of the bacterial suspension. Cells were evenly distributed on the plates with a sterile disposable loop and incubated under micro-aerobic conditions at 37° C. for 72 h as described above. After 24 h four plates were harvested into 10 ml of regular beef stock solution (1 gram [Continental, Unilever, Australia] in 80 ml preheated water that was filter-sterilized through a 0.2 μm Millipore syringe filter). Biochemical tests including urease, catalase and oxidase tests as well as Gram staining were performed to confirm that the stock solution comprised a pure H. pylori culture. The bacterial stock solution was placed on ice and transported to the Department of Gastroenterology and Hepatology at Sir Charles Gairdner Hospital (SCGH) (Western Australia) for administration to the human subject volunteer under SCGH Human Research Ethics Committee approval #2009-062. Approximately 10 9 viable bacteria were then administered orally to a human subject volunteer by ingestion. Two weeks post administration the patient underwent endoscopy and a gastric biopsy taken to confirm H. pylori colonization of the gastric mucosa and the patient was left untreated for a period of at least 12 weeks post administration to maintain H. pylori gastric colonization in the human subject.
Isolation of H. pylori OND86 Strain from Human Gastric Biopsies
Twelve weeks post bacterial inoculation the human subject underwent an endoscopy to collect several gastric biopsies. One gastric antrum biopsy obtained from the subject was processed by homogenization [Qiagen Tissue Lyser] and serially diluted in sterile physiological saline for culturing bacteria from the gastric biopsy on H. pylori selective (DENT's supplement, nalidixic acid and bacitracin) F12 agar medium plates (Thermoscientific, Australia). Bacterial cultures were incubated under micro-aerobic conditions (approximately 83% N 2 , 7% CO 2 , 6% O 2 and 4% H 2 ) at 37° C. for 72 h as described above, and then single bacterial colonies were isolated and expanded three to four times to produce clonal cultures of a H. pylori strain isolated from the gastric biopsy of the patient. Pure clonal H. pylori cultures were verified by Gram staining and biochemical tests as above and the expanded single colonies were frozen in triplicates and stored at −80° C. in F12 broth with 20% (v/v) vegetable glycerol (freezing medium). A pure clonal culture of H. pylori strain derived from H. pylori OND79 after passage in the human subject was named H. pylori OND86 strain and a sample was deposited on 10 Jun. 2014 with the National Measurement Institute (NMI), 1/153 Bertrie Street, Port Melbourne, Victoria, Australia, pursuant to the provisions of the Budapest Treaty, and allocated the NMI Accession No. V14/013016.
Characterization of Clinical Isolates of H. pylori Derived from OND79 Following Passage in a Human Host
Analysis of genomic DNA diversity among the H. pylori parent strain OND79 and six clinical isolates of H. pylori obtained as described above from gastric biopsies of three human volunteers administered with the parent OND79 strain, was performed using a PCR-based Randomly Amplified Polymorphic DNA (RAPD) fingerprinting method as described by Akopyanz et al., (1992) Nucleic Acids Research, 20:5137-5142. The six clinical isolates of H. pylori were labelled “#1157 clone 1”, “#1157 clone 9”, “#86198 clone 1”, “#86198 clone 9”, “#45156 clone 1” and “#45156 clone 9”. Clinical isolates #1157 clone 1, and #1157 clone 9 represent two clonal isolates obtained from the same gastric biopsy of the same human subject (volunteer 1) administered with the parent OND79 strain. Similarly, clinical isolates #86198 clone 1, and #86198 clone 9 represent two clonal isolates obtained from the same gastric biopsy of the same human subject (volunteer 2) administered with the parent OND79 strain. Clinical isolates #86198 clone 1, and #86198 clone 9 represent two clonal isolates obtained from the same gastric biopsy of the same human subject (volunteer 3) administered with the parent OND79 strain. A pure clonal culture of H. pylori clinical isolate #1157 clone 9 was chosen for deposit as H. pylori OND86 strain under NMI Accession No. V14/013016 described above.
RAPD fingerprinting was performed on the H. pylori parent strain OND79 and the six clinical isolates using either the primer “1254” set forth in SEQ ID NO: 3 and having the sequence 5′-CCG CAG CCA A-3′, or the primer “1281” set forth in SEQ ID NO: 4 and having the sequence 5′-AAC GCG CAA C-3′. As shown in FIG. 18 , genomic RAPD fingerprinting was identical for the parent OND79 strain and for each clinical isolate of the human passage derivative strain including the deposited OND86 strain. Such result indicates that a H. pylori strain that has been passaged through an animal host, such as a human host passaged clinical isolates have similar, if not identical, genetic makeup as the parent OND79 strain.
Example 16
H. pylori Strain Derived from OND79 that has been Passaged in a Human Shows Strong Colonization Efficacy of the Gastric Mucosa in Infected Animals
This example demonstrates that a passaged strain or derivative of H. pylori strain OND79 obtained after passaging in a human host is able to colonize the gastric mucosa of animals.
Adult C57BL/6 mice (n=5) were orogastrically inoculated with approximately 1×10 9 live bacteria from pure cultures of each one of the six clinical isolates of the H. pylori obtained after passaging H. pylori OND79 in a human host described in Example 15 i.e., #1157 clone 1, #1157 clone 9, #86198 clone 1, #86198 clone 9, #45156 clone 1 and #45156 clone 9. To determine the level of colonization of the 6 clinical isolated (including a clinical isolated of the H. pylori OND86 strain deposited under NMI Accession No. V14/013016) stomach tissue was harvested from animals 2 weeks after bacterial administration. Stomachs were dissected along the greater curvature and residual food removed by gently washing with PBS. Opened stomachs were placed in 500 μl PBS and homogenized with a 5 mm stainless steel bead for 30 seconds at a frequency of 30 (Qiagen TissueLyser II). Samples were further homogenized for 2 min at a frequency of 10. Serial dilutions of homogenates were plated on H. pylori selective (DENT's supplement, nalidixic acid and bacitracin) F12 agar medium plates. Plates were incubated under micro-aerobic conditions (Anoxomat, approximately 83% N2, 7% CO2, 6% O2 and 4% H2) at 37° C. for 72 h as described above, and then single colonies were counted (i.e., bacterial growth) was determined 5-7 days post plating. Efficacy of infection and colonization of the mouse gastric mucosa for each one of the six isolates of the H. pylori derivative strain obtained after passaging H. pylori OND79 in a human host was measured based on the number of colony forming units (CFU) per stomach. As shown in FIG. 19 , all six clinical isolates (including the deposited H. pylori OND86 strain) were able to effectively infect and colonize the mouse gastric mucosa.
Example 17
H. pylori Strain Derived from OND79 that has been Passaged in a Human Host Such Demonstrate Strong Efficacy in Colonizing the Gastric Mucosa of Animals
This example demonstrates that a passaged strain or derivative of H. pylori strain OND79 obtained after passaging in a human host induces specific anti- H. pylori IgG antibody in animals.
The adult C57BL/6 mice which were orogastrically inoculated with the live bacteria from pure cultures of each one of the six clinical isolates of the H. pylori described in Example 14 were also used to determine the immunogenicity efficacy of the six clinical isolates of the H. pylori described above. Serum was collected from the mice at the end point of the colonization experiment described in Example 16. Ninety-six well plates (Nunc Maxisorb) were coated with 10 μg/ml H. pylori X47 strain cell lysate and incubated overnight at 4° C. Plates were then washed 5 times in PBS/0.05% Tween-20 and blocked with 2% bovine serum albumin (BSA) for 2 hours at 37° C. Plates were washed twice and serum samples (1/20 dilution) were added to the wells in duplicate. The plates were then incubated for 1 h at room temperature (RT), subsequently washed and detection antibody (anti-mouse IgG conjugated to alkaline phosphatase, 1/1000, Sigma) was added. Plates were further incubated for 1 h at RT then washed. Plates were developed using p-NPP for 60 min before the reaction was stopped with 2M NaOH. Antibody titres were expressed as the OD value measured at 405 nm. As shown in FIG. 20 , all six clinical isolates (including the deposited H. pylori OND86 strain) were able to induce antibody specific immune responses to H. pylori.
Taken together the results presented herein demonstrate inter alia that administration of live, killed or inactivated forms of H. pylori to a mammalian subject can modulate the mammalian host immune responses to supress or attenuate allergic immune responses to an allergen, and/or suppress or attenuate allergic airway disease such as allergic asthma. The results presented herein also inter alia demonstrate that formulations comprising live, killed, or inactivated H. pylori can prevent development of an allergic immune response or allergic disease such as allergic airway disease, and can have utility as an immunotherapy in children such as neonates and/or juveniles to prevent or limit the atopic march and the progression of allergic disease in a subject e.g., prevent or limit progression of allergic disease in children with eczema to food allergy and/or severe asthma later in life. Furthermore, as demonstrated herein efficacy in supressing or attenuate allergic immune responses to an allergen conferred by killed and/or inactivated H pylori is not strain specific.
Further Non-Limiting Examples of the Invention
A composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof, optionally further processed to produce a processed H. pylori preparation such as an extract prepared from whole H. pylori cells or proteins isolated from H. pylori cells which are partially or completely purified and/or pre-treated, and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal. The term “composition” as used herein refers a therapeutically-effective or prophylactically-effective amount of the H. pylori bacteria or H. pylori cell lysate or combination thereof which is optionally in admixture with a pharmaceutically acceptable carrier, excipient or diluent suitable for which are administered to a mammal. Generally, the composition is prepared to be administered as a therapeutically effective amount. A pharmaceutically acceptable carrier are any organic or inorganic inert material suitable for administration to a mammalian musoca, e.g., water, gelatin, gum arabic, lactose, starch, magnesium stearate, talc, vegetable oils, polyalkylene-glycols, petroleum jelly and the like, optionally further comprising one or more other pharmaceutically active agents, flavouring agents, preservatives, stabilizers, emulsifying agents, buffers and the like, added in accordance with accepted practices of pharmaceutical compounding. A “therapeutically effective amount” of the composition of the present invention is understood to comprise an amount effective to elicit the desired response e.g., anergy, but insufficient to cause a toxic reaction. As used herein, the term “anergy” refers to either a diminished immune reaction, or the absence of an immune reaction to an antigen as revealed by the lack of an appropriate immune response, possibly entailing a reversible anti-proliferative state which results in decreased responsiveness of an immune cell or cells to an antigen. The term “cell lysate thereof” as used herein refers to a preparation of the H. pylori cells of the present invention, in which the H. pylori cells have been disrupted such that the cellular components of the bacteria are disaggregated or liberated. Persons skilled in the art would be well aware of techniques for producing bacterial cell lysates. For example, H. pylori cells are pelleted and then resuspended in, for example, Dulbecco's phosphate buffered saline (PBS; 10 mM phosphate, 0.14 M NaCl, pH 7.4) and subjected to sonication on ice with a W-375 sonication Ultrasonic processor (Heat Systems-Ultrasonics, Inc., Farmingdale, N.Y.) at 50% duty cycle with pulse and strength setting 5 for three 1 min sessions. If required, insoluble material and unbroken bacterial cells can then be removed by centrifugation. Alternatively, H pylori cells are collected by centrifugation and resuspended in PBS and then lysed by passage through a French press (SLM Instrument Inc., Urbana, Ill.) at 20,000 LB/in. Again, if required, the bacterial lysate are centrifuged at 102,000×g for 10 minutes to remove bacterial debris and/or filtered through a 0.45 μM membrane (Nalgene, Rochester, N.Y.). Another method of producing cell lysate of H. pylori involves freezing and thawing of bacterial pellets in the presence of lysozyme. A particular example of a H. pylori cell lysate is the soluble fraction of a sonicated culture of the H. pylori , e.g., obtained after filtration. Alternatively or in addition, H. pylori are fragmented using a high-pressure homogenizer (e.g. Avestin model EmulsiFlexC5). Optionally, the cell lysate is further inactivated by treatment with formalin, or a comparable agent. Alternatively, the immunotherapy composition according to the present invention is obtained by fractionation and/or purification of one or more proteins from a lysate of H. pylori culture medium. Obviously, a person skilled in the art will appreciate that if a cell lysate is to be used in the inventive methods described herein there is no need to inactivate or “kill” the H. pylori as it will already be disrupted; however, as described supra or infra, the whole H. pylori it needs to be either killed or incapable of colonizing the mucosa of said mammal.
A composition consisting essentially of an isolated H. pylori cell and a cell lysate thereof together with a pharmaceutically accepted carrier. The terms “composition” and “cell lysate” have the meaning given in paragraph 1.
A composition for use in preventing or treating allergy in a mammal comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal. The terms “composition” and “cell lysate” have the meaning given in paragraph 1 supra. A killed H. pylori is in a state of irreversible bacteriostasis. While the H. pylori cell retains its structure and thus retains, for example, the immunogenicity, antigenicity, and/or receptor-ligand interactions associated with a wild-type H. pylori cell, it is not capable of replicating. There are various methods known in the art to produce killed (whole) bacteria including H. pylori , such as exposure to ultraviolet (UV) irradiation, exposure to extreme heat and/or pressure and/or infection with a bacteriophage. In some embodiments, the killed or inactivated H. pylori may remain metabolically active e.g., it may wholly retain or partially retain a cell wall and a cell membrane and certain enzymatic functions such as the presence of catalase and superoxide dismutase (SOD) activities for free radical harvesting, however be incapable of colonizing the gastric mucosa of a subject to whom it is administered. A preferred method of producing killed or inactived H. pylori is by heat, UV irradiation, pressure or chemical means. Exemplary means of inactivation by irradiation include exposure to ultraviolet irradiation or gamma irradiation. Once a killed or inactivated H. pylori strain, or H. pylori strain that is naturally incapable of colonizing the mucosa of a mammal, or H. pylori cell lysate has been produced, it are formulated in to a composition of the present invention.
A composition according to any one of paragraphs 1 to 3, wherein the H. pylori is killed before use in the invention by, for example, inactivating or killing the strain, or wherein the strain is naturally incapable of colonizing the mucosa of a mammal.
A composition according to any one of paragraphs 1 to 4, wherein the H. pylori is a cagA-deficient or cagA − strain, and preferably a strain that is also positive for toxigenic s1 and m1 alleles of the VacA gene. The terms “cagA − ,” “cagA minus,” “cagA deficient” and the like refer to the absence of the H. pylori virulence factor cagA (cytotoxin-associated gene A), which is a 120-145 kDa protein encoded on the 40 kb cag pathogenicity island (PAI) (Hatakeyama & Higashi, (2005), Cancer Science., 96: 835-843). H. pylori strains are divided into cagA + (positive) or cagA − (negative) strains, of which around 60% of H. pylori isolates in Western countries are positive, whereas the majority of East Asian isolates are negative e.g., Hatakeyama & Higashi, (2005).
A composition according to any one of paragraphs 1 to 5, wherein the H. pylori has the characteristics of a strain of H. pylori selected from the group consisting of OND737, as deposited in the National Measurement Institute under Accession No. V09/009101; OND738, as deposited in the National Measurement Institute under Accession No. V09/009102; OND739, as deposited in the National Measurement Institute under Accession No. V09/009103; OND248, as deposited in the National Measurement Institute under Accession No. V10/014059; OND256 as deposited in the National Measurement Institute under Accession No. V10/014060, OND740 as deposited in the National Measurement Institute under Accession No. V09/009104; OND79 as deposited in the National Measurement Institute under Accession No. V13/023374 and/or OND86 as deposited in the National Measurement Institute under Accession No. V14/013016, or passaged strain, a mutant or a derivative thereof. The term “mutant” or “derivative” as used herein, refers to H. pylori which is produced from or derived from a strain of H. pylori described herein and as such has genomic DNA at least about 80%, preferably at least about 90%, and most preferably at least about 95%, identical to that of H. pylori strain OND737, OND738, OND739, OND740, OND248, OND256, OND79 or OND86.
A composition according to any one of paragraphs 1 to 6, wherein the H. pylori has been passaged through an animal host before it is inactivated for use in the present invention.
A composition according to any one of paragraphs 1 to 7, wherein the H. pylori is further genetically modified prior to being inactivated to comprise one or more nucleic acid molecule(s) encoding at least one heterologous antigen or a functional fragment thereof. This means that the H. pylori will generally express the antigen before it is inactivated. A “genetically modified” H. pylori refers to a H. pylori bacterium that differs in its phenotype and/or genotype from that of the corresponding wild type H. pylori in that it comprises an alteration to or an addition to the genetic makeup present in H pylori . Methods for the genetic modification of the H pylori are well-known in the art: See, for example, Sambrook & Russell, (2001), “Molecular Cloning—A Laboratory Manual”, Cold Spring Harbor Laboratory Press, New York, 3 rd Edition. An “isolated genetically modified H. pylori cell may be present in a mixed population of H. pylori cells. In some embodiments, the genetically modified H pylori will comprise one or more nucleic acid molecule(s) encoding at least one heterologous antigen or a functional fragment thereof. The nucleic acid molecule may reside extra-chromosomally or will preferably integrate into the genome of the H. pylori . The term “nucleic acid” as used herein refers to a polymeric form of nucleotides of any length, either ribonucleotides or deoxynucleotides. Thus, this term includes, but is not limited to, single-, double-, or multi-stranded DNA or RNA, genomic DNA, cDNA, DNA-RNA hybrids, or a polymer comprising purine and pyrimidine bases or other natural, chemically or biochemically modified, non-natural, or derivatized nucleotide bases. The term “heterologous nucleic acid,” as used herein, refers to a nucleic acid wherein at least one of the following is true: (a) the nucleic acid is foreign (“exogenous”) to (i.e., not naturally found in) H. pylori ; (b) the nucleic acid comprises two or more nucleotide sequences or segments that are not found in the same relationship to each other in nature, e.g., the nucleic acid is recombinant. “Recombinant,” as used herein, means that a particular nucleic acid (DNA or RNA) is the product of various combinations of cloning, restriction, and/or ligation steps resulting in a construct having a structural coding or non-coding sequence distinguishable from endogenous nucleic acids found in natural systems. Generally, DNA sequences encoding the structural coding sequence are assembled from cDNA fragments and short oligonucleotide linkers, or from a series of synthetic oligonucleotides, to provide a synthetic nucleic acid which is capable of being expressed from a recombinant transcriptional unit contained in a cell or in a cell-free transcription and translation system. Such sequences are provided in the form of an open reading frame uninterrupted by internal non-translated sequences, or introns, which are typically present in eukaryotic genes. Genomic DNA comprising the relevant sequences can also be used in the formation of a recombinant gene or transcriptional unit. Sequences of non-translated DNA may be present 5′ or 3′ from the open reading frame, where such sequences do not interfere with manipulation or expression of the coding regions, and may indeed act to modulate production of a desired product by various mechanisms. Thus, e.g., the term “recombinant” polynucleotide or “recombinant” nucleic acid refers to one which is not naturally occurring, e.g., is made by the artificial combination of two otherwise separated segments of sequence through human intervention. This artificial combination is often accomplished by either chemical synthesis means, or by the artificial manipulation of isolated segments of nucleic acids, e.g., by genetic engineering techniques. Such is usually done to replace a codon with a redundant codon encoding the same or a conservative amino acid, while typically introducing or removing a sequence recognition site. Alternatively, it is performed to join together nucleic acid segments of desired functions to generate a desired combination of functions. This artificial combination is often accomplished by either chemical synthesis means, or by the artificial manipulation of isolated segments of nucleic acids, e.g., by genetic engineering techniques. In some embodiments, the heterologous nucleic acid sequence is introduced into a H. pylori strain of the present invention by a vector. By “vector” is meant a recombinant nucleic acid, generally recombinant DNA, which has been generated for the purpose of the expression and/or propagation of a specific nucleic acid sequence, or is to be used in the construction of other recombinant nucleic acid sequences. The vector often comprises DNA regulatory sequences as well as the nucleic acid sequence of interest. The terms “DNA regulatory sequences”, “control elements,” and “regulatory elements,” refer to transcriptional and translational control sequences, such as promoters, enhancers, polyadenylation signals, terminators, protein degradation signals, and the like, that provide for and/or regulate expression of a nucleic acid sequence in a H. pylori cell. The term “transformation” is used interchangeably herein with “genetic modification” and refers to a permanent or transient genetic change induced in a H. pylori cell following introduction of a new nucleic acid. Genetic change (“modification”) are accomplished either by incorporation of the new DNA into the genome of the H. pylori cell, or by transient or stable maintenance of the new DNA as an episomal element such as an expression vector, which may contain one or more selectable markers to aid in their maintenance in the recombinant H. pylori cell. Suitable methods of genetic modification include transfection, conjugation, protoplast fusion, electroporation, particle gun technology, calcium phosphate precipitation, direct microinjection, and the like. A general discussion of these methods are found in Ausubel, et al., Short Protocols in Molecular Biology, 3 rd ed., Wiley & Sons, 1995. The DNA regulatory sequences and nucleic acid sequence of interest are often “operably linked,” which refers to a juxtaposition wherein the components so described are in a relationship permitting them to function in their intended manner. For instance, a promoter is operably linked to a coding sequence if the promoter effects its transcription or expression. As used herein, the terms “heterologous promoter” and “heterologous control regions” refer to promoters and other control regions that are not normally associated with a particular nucleic acid in nature. For example, a “transcriptional control region heterologous to a coding region” is a transcriptional control region that is not normally associated with the coding region in nature. In some embodiments, the nucleic acid sequence encodes a heterologous antigen. A “heterologous antigen” is one not native to H. pylori , i.e., not expressed by H. pylori in nature or prior to introduction into H. pylori . An “antigen” refers to any immunogenic moiety or agent, generally a macromolecule, which can elicit an immunological response in a mammal. The term may be used to refer to an individual macromolecule or to a homogeneous or heterogeneous population of antigenic macromolecules. As used herein, “antigen” is generally used to refer to a protein molecule or portion thereof which contains one or more epitopes, which is encoded by a nucleic acid sequences as herein defined. In various examples of the invention, the antigen contains one or more T cell epitopes. A “T cell epitope” refers generally to those features of a peptide structure which are capable of inducing a T cell response. In this regard, it is accepted in the art that T cell epitopes comprise linear peptide determinants that assume extended conformations within the peptide-binding cleft of MHC molecules, (Unanue et al., (1987), Science, 236:551-557). As used herein, a T cell epitope is generally a peptide having at least about 3-5 amino acid residues, and preferably at least 5-10 or more amino acid residues. The ability of a particular antigen to stimulate a cell-mediated immunological response may be determined by a number of well-known assays, such as by lymphoproliferation (lymphocyte activation) assays, CTL cytotoxic cell assays, or by assaying for T-lymphocytes specific for the antigen in a sensitized subject. See, e.g., Erickson et al., (1993), J. Immunol., 151:4189-4199; and Doe et al., (1994), Eur. J. Immunol., 24:2369-2376. In other examples of the invention, the antigen contains one or more B cell epitopes. A “B cell epitope” generally refers to the site on an antigen to which a specific antibody molecule binds. The identification of epitopes which are able to elicit an antibody response is readily accomplished using techniques well known in the art. See, e.g., Geysen et al., (1984), Proc. Natl. Acad. Sci. USA, 81:3998-4002 (general method of rapidly synthesising peptides to determine the location of immunogenic epitopes in a given antigen); U.S. Pat. No. 4,708,871 (procedures for identifying and chemically synthesising epitopes of antigens); and Geysen et al., (1986), Molecular Immunology, 23:709-715 (technique for identifying peptides with high affinity for a given antibody). In some embodiments, the nucleic acid sequence encoding one or more antigens (allergens) are inserted into a suitable H. pylori shuttle vector, e.g., a shuttle plasmid with selectable markers, e.g., antibiotic markers, to assess their transformability. Broadly, a suitable shuttle vector will include one, two, three or more of the following features, a cloning site, a H. pylori origin of replication, an E. coli origin of replication, and an antibiotic resistance gene and/or selectable marker. Art-known vectors suitable for this purpose, or readily adaptable for this purpose include, for example, the recombinant shuttle plasmid pHR106 described by Roberts et al. (Appl Env Mircobiol., 54: 268-270 (1988)); the PJIR 750 and PJIR 751 plasmids described by Bannam et al. (Plasmid, 29:233-235 (1993)); the promoter-less PPSV promoter selection vector of Matsushita et al. (Plasmid, 31, 317-319 (1994)); the shuttle plasmids pJIR1456 and pJIR1457, described by Lyras et al. (Plasmid, 39, 160-164 (1988)); and the pAK201 shuttle vector described by Kim et al. (Appl Environ Microbiol., 55, 360-365(1989)), the contents of which are incorporated herein by reference in their entireties. Alternatively, homologous recombination are used to introduce an exogenous sequence into the genome of the H. pylori . Once the vector, e.g., a shuttle vector, has been produced then nucleic acid transfer protocols are used including transformation/transfection, electroporation, liposome mediated nucleic acid transfer, N-[1-(2,3-Dioloyloxy)propyl]-N,N,N-trimethyl ammonium methyl sulfate meditated transformation, and others. One skilled in the art will be readily able to select the appropriate tools and methods for genetic modifications of the H. pylori according to the knowledge in the art and design choice. Once the H. pylori or genetically modified H. pylori of the present invention has been isolated, passaged through a host and/or prepared, by for example culturing it are used in the present methods.
A composition according to paragraph 8, wherein the nucleic acid molecule resides extra-chromosomally.
A composition according to paragraph 8, wherein the nucleic acid molecule is chromosomally inserted.
A composition according to any one of paragraphs 8 to 10, wherein the heterologous antigen or a functional fragment thereof will encode an environmental antigen. For example, the antigen are obtained or derived from any known allergen including a recombinant allergen. Exemplary recombinant allergens are provided in the tabular representation provided below:
Recombinant Allergens
Source
Allergen
Reference
Shrimp/lobster
tropomyosin
Leung et al. (1996) J. Allergy Clin. Immunol. 98: 954 961
Pan s 1
Leung et al. (1998) Mol. Mar. Biol. Biotechnol. 7: 12 20
Ant
Sol i 2 (venom)
Schmidt et al. J Allergy Clin Immunol., 1996, 98: 82 8
Bee
Phospholipase A2 (PLA)
Muller et al. J Allergy Clin Immunol, 1995, 96: 395 402
Forster et al. J Allergy Clin Immunol, 1995, 95: 1229 35
Muller et al. Clin Exp Allergy, 1997, 27: 915 20
Hyaluronidase (Hya)
Soldatova et al. J Allergy Clin Immunol, 1998, 101: 691 8
Cockroach
Bla g Bd9OK
Helm et al. J Allergy Clin Immunol, 1996, 98: 172 180
Bla g 4 (a calycin)
Vailes et al. J Allergy Clin Immunol, 1998. 101: 274 280
Glutathione S-
Arruda et al. J Biol Chem, 1997, 272: 20907 12
transferase
Per a 3
Wu et al. Mol Immunol, 1997, 34: 1 8
Dust mite
Der p 2 (major allergen)
Lynch et al. J Allergy Clin Immunol, 1998, 101: 562 4
Hakkaart et al. Clin Exp Allergy, 1998, 28: 169 74
Hakkaart et al. Clin Exp Allergy, 1998, 28: 45 52
Hakkaart et al. Int Arch Allergy Immumol, 1998, 115 (2): 150 6
Mueller et al. J Biol Chem, 1997, 272: 26893 8
Der p2 variant
Smith et al. J Allergy Clin Immunol, 1998, 101: 423 5
Der f2
Yasue et al. Clin Exp Immunol, 1998, 113: 1 9
Yasue et al. Cell Immunol, 1997, 181: 30 7
Der p10
Asturias et al. Biochim Biophys Acta, 1998, 1397: 27 30
Tyr p 2
Eriksson et al. Eur J Biochem, 1998
Hornet
Antigen 5 aka Dol m V
Tomalski et al. Arch Insect Biochem Physiol, 1993
(venom)
22: 303 13
Mosquito
Aed a 1 (salivary
Xu et al. Int Arch Allergy Immunol, 1998, 115: 245 51
apyrase)
Yellow jacket
antigen 5, hyaluronidase
King et al. J Allergy Clin Immunol. 1996, 98: 558 600
and phospholipase
(venom)
Cat
Fel d 1
Slunt et al J Allergy Clin Immunol, 1995, 95: 1221 8
Hoffmann et al. (1997) J Allergy Clin Immunol 99: 227 32
Hedlin Curr Opin Pediatr, 1995, 7: 676 82
Cow
Bos d 2 (dander;
Zeiler et al. J Allergy Clin Immunol, 1997, 100: 721 7
a lipocalin)
Rautiainen et al. Biochem Bioph. Res Comm., 1998, 247: 746 50
□-lactoglobuin (BLG,
Chatel et al. Mol Immunol, 1996, 33: 1113 8
major cow milk allergen)
Lehrer et al. Crit Rev Food Sci Nutr, 1996, 36: 553 64
Dog
Can f1 and Can f2,
Konieczny et al. Immunology, 1997, 92: 577 86
salivary lipocalins
Spitzauer et al. J Allergy Clin Immunol, 1994, 93: 614 27
Vrtala et al. J Immunol, 1998, 160: 6137 44
Horse
Equ e1 (major allergen,
Gregoire et al. J Biol Chem, 1996, 271: 32951 9
a lipocalin)
Mouse
mouse urinary protein
Konieczny et al. Immunology, 1997, 92: 577 86
(MUP)
Insulin
Ganz et al. J Allergy Clin Immunol, 1990,86: 45 51
Grammer et al. J Lab Clin Med, 1987, 109: 141 6
Gonzalo et al. Allergy, 1998, 53: 106 7
Interferons
interferon alpha 2c
Detmar et al. Contact Dermatis, 1989, 20: 149 50
topomyosin
Leung et al. J Allergy Clin Immunol, 1996, 98: 954 61
Barley
Hor v 9
Astwood et al. Adv Exp Med Biol, 1996, 409: 269 77
Birch
pollen allergen, Bet v 4
Twardosz et al. Biochem Bioph. Res Comm., 1997, 23 9: 197
rBet v 1 Bet v 2
Pauli et al. J Allergy Clin Immunol, 1996, 97: 1100 9
(profilin)
van Neerven et al. Clin Exp Allergy, 1998, 28: 423 33
Jahn-Schmid et al. Immunotechnology, 1996, 2: 103 13
Breitwieser et al. Biotechniques, 1996, 21: 918 25
Fuchs et al. J Allergy Clin Immunol, 1997, 100: 3 56 64
Brazil nut
globulin
Bartolome et al. Allergol Immunopathol, 1997, 25: 135 44
Cherry
Pru a 1 (major allergen)
Scheurer et al. Mol Immunol, 1997, 34: 619 29
Corn
Zml3 (pollen)
Heiss et al. FEBS Lett, 1996, 381: 217 21
Lehrer et al. Int Arch Allergy Immunol, 1997, 113: 122 4
Grass
Phl p 1, Phl p 2, Phl p 5
Bufe et al. Am J Respir Crit Cart Med, 1998, 157: 1269 76
(timothy grass pollen)
Vrtala et al. J Immunol Jun. 15, 1998, 160: 6137 44
Niederberger et al J Allergy Clin Immun., 1998, 101: 258 64
Hol l 5 velvet grass
Schramm et al. Eur J Biochem, 1998, 252: 200 6
pollen
Bluegrass allergen
Zhang et al. J Immunol. 1993; 151: 791 9
Cyn d 7 Bermuda grass
Smith et al. Int Arch Allergy Immunol, 1997, 114: 265 71
Cyn d 12 (a profilin)
Asturias et al. Clin Exp Allergy, 1997, 27: 1307 13
Fuchs et al. J Allergy Clin Immunol, 1997, 100: 356 64
Japanese Cedar
Jun a 2 ( Juniperus ashei )
Yokoyama et al. Biochem. Biophys. Res. Commun., 2000, 275:
195
202
Cry j 1, Cry j 2
Kingetsu et al. Immunology, 2000, 99: 625 629
( Cryptomeria japonica )
Juniper
Jun o 2 (pollen)
Tinghino et al. J Allergy Clin Immunol, 1998, 101: 772 7
Latex
Hev b 7
Sowka et al. Eur J Biochem, 1998, 255: 213 9
Fuchs et al. J Allergy Clin Immunol, 1997, 100: 3 56 64
Mercurialis
Mer a I (profilin)
Vall verdu et al. J Allergy Clin Immunol, 1998, 101: 3 63 70
Mustard
Sin a I (seed)
Gonzalez de la Pena et al. Biochem Bioph. Res Comm., 1993,
(Yellow)
190: 648 53
Oilseed rape
Bra r I pollen allergen
Smith et al. Int Arch Allergy Immunol, 1997, 114: 265 71
Peanut
Ara h I
Stanley et al. Adv Exp Med Biol, 1996, 409 213 6
Burks et al. J Clin Invest, 1995, 96: 1715 21
Burks et al. Int Arch Allergy Immonol, 1995, 107: 248 50
Poa
pratensis
Poa p9
Parronchi et al. Eur J Immunol, 1996, 26: 697 703
Astwood et al. Adv Exp Med Biol, 1996, 409: 269 77
Ragweed
Amb a I
Sun et al. Biotechnology Aug, 1995, 13: 779 86
Hirsehwehr et al. J Allergy Clin Immunol, 1998, 101: 196 206
Casale et al. J Allergy Clin Immunol, 1997, 100: 110 21
Rye
Lol p I
Tamborini et al. Eur J Biochem, 1997, 249: 886 94
Walnut
Jug r I
Teuber et al. J Allergy Clin Immun., 1998, 101: 807 14
Wheat
allergen
Fuchs et al. J Allergy Clin Immunol, 1997, 100: 356 64
Donovan et al. Electrophoresis, 1993, 14: 917 22
Aspergillus
Asp f 1, Asp f 2, Asp f 3,
Crameri et al. Mycoses, 1998, 41 Suppl 1: 56 60
Asp f 4, rAsp f 6
Hemmann et al. Eur J Immunol, 1998, 28: 1155 60
Banerjee et al. J Allergy Clin Immunol, 1997, 99: 821 7
Crameri Int Arch Allergy Immunol, 1998, 115: 99 114
Crameri et al. Adv Exp Med Biol, 1996, 409: 111 6
Moser et al. J Allergy Clin Immunol, 1994, 93: 1 11
Manganese superoxide
Mayer et at Int Arch Allergy Immunol, 1997, 113: 213 5
dismutase (MNSOD)
Blomia
allergen
Caraballo et al. Adv Exp Med Biol, 1996, 409: 81 3
Penicillinium
allergen
Shen et al. Clin Exp Allergy, 1997, 27: 682 90
Psilocybe
Psi e 2
Homer et al. Int Arch Allergy Immunol, 1995, 107: 298 300
A composition according to any one of paragraphs 8 to 11, wherein the nucleic acid molecule encoding the heterologous antigen will reside in a plasmid vector comprising (a) a nucleotide sequence encoding the heterologous antigen and (b) a control or regulatory sequence operatively linked thereto which is capable of controlling the expression of the nucleic acid when the vector is transformed into a H. pylori strain.
A composition according to any one of paragraphs 1 to 12, wherein the composition further comprises an adjuvant. Any adjuvant known in the art may be used.
A composition according to paragraph 13, wherein the adjuvant is selected from 5 the group consisting of alum, pertussis toxin, Lacto fucopentaose III, phosphopolymer, complete Freund's adjuvant, monophosphoryl lipid A, 3-de-O-acylated monophosphoryllipid A (3D-MPL), aluminium salt, CpG-containing oligonucleotides, immunostimulatory DNA sequences, saponin, MONTANIDE® ISA 720, SAF, ISCOMS, MF-59®, SBAS-3, SBAS-4, Detox, RC-529, aminoalkyl glucosaminide 4-phosphate, 10 and LbeiF4A or combinations thereof.
A composition according to any one of paragraphs 1 to 14, wherein the composition is formulated to prevent or treat anergy and/or allergy in a mammal. The dosage and duration of administration of the composition to a mammal will be determined by the health professional attending the mammalian subject in need of treatment, and will consider the age, sex and weight of the subject, the specific H. pylori and nucleic acid molecule being expressed or the state in which the H. pylori and/or cell lysate thereof e.g., whether the H. pylori is killed or alive or the strain of H. pylori being used. The various delivery forms of the compositions are readily prepared for use in the practice of the present invention given the specific types and ratios of specific H. pylori , plasmid vectors and other delivery mechanisms described herein, and those formulation techniques known to those in the formulary arts, such as are described in Remington's Pharmaceutical Sciences, 20th edition, Mack Publishing Company, which text is specifically incorporated herein by reference. One application of the composition of the invention is to alter, ameliorate, or change the immune response to one or allergens (antigens), thereby resulting in anergy. The terms “altering or altered,” “effecting or effected” or “altering relative to” are all used herein to imply or suggest that the specific immune response of an individual has been modified when compared to specific immune response before the methods of the invention have been used. Allergic diseases that are specifically considered to be prevented and/or treated by the methods of the present invention include, but are not limited to contact dermatitis (Kapsenberg et al., Immunol Today 12:392-395), chronic inflammatory disorders such as allergic atopic disorders (against common environmental allergens) including allergic asthma (Walker et al., (1992), Am. Rev. Resp. Dis. 148:109-115), atopic dermatitis (van der Heijden et al., (1991), J. Invest. Derm. 97:389-394); hyper-IgE syndrome, Omenn's syndrome, psoriases, hay fever, allergic rhinitis, urticaria, eczema and food allergies. The H. pylori containing composition may be formulated for administration or delivery “orally,” “enterally,” or “non-parenterally,” i.e., by a route or mode along the alimentary canal.
A composition according to paragraph 15, wherein the allergy is selected from the group consisting of contact dermatitis, chronic inflammatory disorders, allergic atopic disorders, allergic asthma, atopic dermatitis, hyper-IgE syndrome, Omenn's syndrome, psoriases, hay fever and allergic rhinitis.
A composition according to any one of paragraphs 1 to 16, wherein the composition is formulated to be orally administered. Examples of “oral” routes of administration of a composition include, without limitation, swallowing liquid or solid forms of a composition from the mouth, administration of a composition through a nasojejunal or gastrostomy tube, intraduodenal administration of a composition, and rectal administration, e.g., using suppositories that release the H. pylori strain as described herein to the lower intestinal tract of the alimentary canal.
A method of treatment or prevention of allergy in a mammal at risk of developing said method comprising the step of administering to said mammal an effective amount of a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal, wherein said composition, upon administration, provides protective immunity against said allergy. Preferably, the composition is the composition according to any one of paragraphs 1 to 17. The term “mucosa” in this context refers to the lining of mammalian tissue including, but not limited to oral mucosa esophageal mucosa, gastric mucosa, nasal mucosa, bronchial mucosa and uterine mucosa. Preferably, the mucosa is the gastric mucosa. Mucosal delivery may encompass delivery to the mucosa. Oral mucosal delivery includes buccal, sublingual and gingival routes of delivery. Accordingly, the present invention relates to a method in which said mucosal delivery is chosen from the group consisting of buccal delivery, pulmonary delivery, ocular delivery, nasal delivery and oral delivery. Preferably, said mucosal delivery is oral delivery. The term “mammal” or “mammalian subject” or “individual” are used interchangeably herein to refer to any member of the subphylum Chordata, including, without limitation, humans and other primates, including non-human primates such as chimpanzees and other apes and monkey species; farm animals such as cattle, sheep, pigs, goats and horses; domestic mammals such as dogs and cats; laboratory animals including rodents such as mice, rats and guinea pigs; birds, including domestic, wild and game birds such as chickens, turkeys and other gallinaceous birds, ducks, geese, and the like. The method is intended for use in any of the above vertebrate species. The term “treatment” is used herein to mean affecting an individual or subject, their tissue or cells to obtain a desired pharmacological and/or physiological effect, such as by prophylaxis i.e., complete or partial prevention of allergic disease or sign or symptom thereof, or by therapy i.e., partial or complete cure of allergic disease, including: (a) preventing the allergic disease from occurring in a subject that may be predisposed to the allergic disease, but has not yet been diagnosed as having them; (b) inhibiting the allergic disease, i.e., arresting its development; or (c) relieving or ameliorating the symptoms of the allergic disease, i.e., cause regression of the symptoms of the allergic disease.
A method of treatment or prevention of allergy in an immunologically naive mammal at risk of developing said allergy, said method comprising the step of: (i) identifying a mammal at risk of developing an allergy; (ii) administering to said mammal a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal and (iii) allowing sufficient time to elapse to enable anergy to develop. Preferably, the composition is the composition according to any one of paragraphs 1 to 17. The terms “mucosa” and “mammal” and “treatment” have the meanings given in paragraph 18 hereof.
A method of treatment or prevention of allergy in a mammal comprising the step of administering to said mammal an effective amount of a composition comprising an isolated H. pylori cell, a cell lysate thereof or combination thereof and a pharmaceutically accepted carrier, wherein said H. pylori cell is either killed or incapable of colonizing the mucosa of said mammal, wherein said composition, upon administration, provides protective immunity against said allergy. Preferably, the composition is the composition according to any one of paragraphs 1 to 17. The terms “mucosa” and “mammal” and “treatment” have the meanings given in paragraph 18 hereof.
A method according to any one of paragraphs 18 to 20, wherein the mammal is a dog, a cat, a livestock animal, a primate or a horse.
A method according to paragraph 21, wherein the primate is a human. Adult and newborn and infant humans, are intended to be treated by this invention. In some embodiments, the mammal is a human child between 3 months and 7 years old, not less than 6 months old, more preferably not less than 9 months old. In some embodiments, the mammal is a human individual older than 7 years. Because in early childhood most individuals will not yet have been exposed to sensitisation by environmental allergens, it is considered that this period provides the optimum opportunity to predict the likely onset of allergy.
A method according to paragraph 22, wherein the human is below the age of about 5.
A method according to paragraph 23, wherein the human is below the age of 2 years.
A method according to any one of paragraphs 18 to 24, wherein the allergy is selected from the group consisting of contact dermatitis, chronic inflammatory disorders, allergic atopic disorders, allergic asthma, atopic dermatitis, hyper-IgE syndrome, Omenn's syndrome, psoriases, hay fever and allergic rhinitis.
A kit for treating and/or preventing allergy in a mammal comprising:
i). a composition according to any one of paragraphs 1 to 17; and ii). instructions for use in a method according to any one of paragraphs 18 to 25.
A method of generating a H. pylori strain that is able to provide protective immunity against allergy comprising the steps of:
(a) providing an isolated H. pylori cell that is;
(i) incapable of colonizing the mucosa of a mammal and/or (ii) cagA minus (cagA) and optionally positive for the toxigenic s1 and m1 alleles of the VacA gene;
(b) optionally passaging said H. pylori cell through an animal host; and (c) optionally inactivating or killing said H. pylori cell.
|
The present invention relates to the field of preventing or reducing incidence or severity of an allergic immune response, and compositions for preventing or reducing incidence or severity of an allergic immune response. For example, the present invention provides compositions comprising inactivated and/or killed cells of Helicobacter pylori or a cell lysate thereof, and methods and/or uses thereof for delaying or preventing or interrupting or slowing onset of one or more allergic conditions in a subject.
| 0
|
REFERENCED APPLICATION
United States Application, Ser. No. 07/451,430, now issued as U.S. Pat. No. 5,084,706 entitled "Synchronization Of Very Short Pulse Microwave Signals For Array Applications" invented by Gerald F. Ross and Richard M. Mara and having the same assignee as the instant application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the field of radar transmitters and more particularly to short pulse generation and radiation and time domain electromagnetics.
2. Description of the Prior Art
Radar Systems have a greater range and ranges resolution when the transmitted signal has a high peak power and short pulse duration. Conventional designs use a Marx generator to develop these signals. However, these designs have a limited pulse repetition frequency and pulse duration, and provide reduced high peak power. However, modifications to the conventional Marx generator eliminate these deficiencies. Therefore, a detailed description of the Marx generator is in order to better understand the invention.
Avalanche transistors were designed into the transmitter system to accomplish this need for improved performance at a very low cost. Previous attempts to increase the pulse repetition frequency (prf) of the source have been limited by avalanche transistor dissipation and power supply drain. As an example, the Marx generator configuration consisting of avalanche transistor sources permits one to charge a bank of capacitors in parallel from a low battery voltage and then discharge them in series creating a high voltage pulse. The Marx generator configuration is described in a text written by Miller, et al, entitled, "Time domain Measurements in Electromagnetics", Chapter 4, pp. 100-101, Van Nostrand Reinhold Company, N.Y., 1986.
To significantly increase the prf of the source beyond what has been achieved by other investigators, it is important to recognize the sources of current drain and power dissipation in the system. At first inspection, it appears that the only source of current drain from the dc supply is due to the charging of the coupling capacitors Cn of the Marx generator. Note that in the Marx generator design the capacitors are charged in parallel, and that the dissipation limitations of the avalanche transistors (e.g., an RS 3500 or the equivalent) determine the maximum prf. It can be shown mathematically that the average current during the charge cycle is determined only by the capacitor Cn. The two charging resistors R should be made as small as possible to ensure recharging capacitor Cn quickly for achieving a high prf. Since these resistors directly load the short pulse that is produced during the avalanche mode (e.g., they are effectively in parallel with an avalanche diode and balun circuit) they cannot be made too low in value. For example, in a 12 stage avalanche transistor Marx generator, where R=6.8K, there are effectively 24-6.8K resistors in parallel constituting about a 280 ohm load or the driving point impedance of the balun when exciting an antenna which results in a reduction of the high voltage signal. The decrease in output voltage can only be compensated for by increasing the number of avalanche transistor stages which, in turn, further increases the loading resulting in a vanishing small gain.
Other investigators have generated only baseband or video pulses at repetition frequencies of 1 kHz or less using this type of generator.
OBJECTS OF THE INVENTION
Accordingly, it is a primary object of the invention to have an improved radar system.
It is an object of the invention to have an improved radar transmitter.
It is an object of the invention to have an improved radar transmitter radiating a higher pulse repetition frequency.
It is another object of the invention to have an improved radar transmitter radiating a very short duration microwave pulse with high peak power.
It is still another object of the invention to achieve high peak power, short pulse microwave radiation, using conventional components at the lowest possible cost.
SUMMARY OF THE INVENTION
The above objects and advantages are achieved in a preferred embodiment of the present invention. According to the preferred embodiment, this invention describes a high voltage, very short pulse, microwave radiating source using low-cost components, and capable of operating at high pulse repetition frequencies. The source is activated by an ordinary video trigger commensurate with driving TTL logic; for example, a 2 volt, 10 ns rise time positive trigger will cause a chain of N (where N may be 12 or greater) avalanche transistors connected in a Marx generator configuration to threshold resulting in a 1,200 volt or greater baseband pulse having a rise time of less than 100 ps and a duration of about 3 ns driving the input port of a dipole antenna. The dipole is excited by a balun. The balun is a matching device that connects a coaxial to a two-wire line. The Marx generator configuration permits one to charge a bank of capacitors in parallel from a low battery voltage and then discharge them in series creating a high voltage pulse. The circuit assures that the capacitors are charged during a short interval before application of the main avalanche trigger, and the power supply is disconnected just prior to triggering the modified Marx generator.
The high voltage baseband (or video) pulse produced is used directly to excite a microwave antenna. The results is the radiation of the impulse response of a balun-antenna cavity. Measurements taken produce less than a 1 ns duration radiated pulse having a nominal center frequency of 2.5 GHz. The centroid of the spectrum of the radiated pulse can be shifted up or down in frequency by redesigning the balun-antenna cavity. One of the key features of the instant invention is the ability to achieve this short pulse duration broadband microwave radiation at pulse repetition frequencies as high as 30 kHz or greater.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a circuit diagram of a modified Marx generator configuration.
FIG. 2 shows the balun-dipole mechanical configuration.
FIG. 3 shows the balun dipole mounted above a groundplane.
FIG. 4 shows the wave shape of an output S-band pulsed signal received at 1 meter.
FIG. 5a is a timing chart gating sequence.
FIG. 5b is a block diagram of the S-band short pulse source.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A diagram of a conventional Marx generator 2 driving a modified balun and antenna is shown in FIG. 1. An advantage of using the Marx generator concept is to achieve a large output pulse at port B while avoiding the use of a high voltage dc power supply, Vcc. In the absence of a trigger pulse at port A, each of the capacitors, C3, C4, . . . Cn charge to Vcc through the resistor pairs R6, R11; R7, R12; RM+5; . . . , respectively. A capacitor C2 charges through a resistor R5 and the emitter resistor of a trigger avalanche transistor Q1. A capacitor C1 charges through a resistor R1 and provides the source of charge for a transistor Q1. After a capacitor C1 is fully charged and a sufficiently large positive trigger is applied to Port A, transistor Q1 avalanches discharging capacitor C1, essentially, into a 50 ohm load R4. This voltage is then in series with the voltage already across capacitor C2 causing transistor Q2 to over-voltage and avalanche. This larger voltage, in turn, is instantaneously in series with capacitor C3 causing transistor Q3 to over-voltage and avalanche. The chain of events continue until each of the tandem connected avalanche transistors, Q4, Q5, . . . Qn rapidly break down. When the avalanche transistor breaks down the collector, base, and emitter junctions, virtually, short circuit placing the high voltage pulse traveling down the line incident on an avalanche diode D2 part of a balun 9, essentially in series with resistor R4 and the antenna load at Part B. The 1-2 nanosecond rise time high voltage (e.g., 1200 volt) pulse produced by, for example, a 12 stage Marx generator chain firing causes the back biased diode D2 to go into avalanche breakdown mode speeding up the transition to 100 ps or less. Small 10 pf capacitors C, are placed between the base and collector junctions to help speed-up the basic high voltage baseband pulse produced by the Marx Generator. Diode D1 prevents any kickout pulse from returning to the trigger source. Resistor R2 terminates the trigger source, while resistor R3 provides a dc return for the base circuit of Q1. A capacitor C20 is used to bypass the power supply. When triggered by a 2 volt, 100 ns duration positive pulse, a 1200 volt, 1.5 ns rise time baseband pulse is delivered to a coaxial balun having a driving point impedance (resistance) of 50 ohms, resulting in a peak current of 24 amperes. This is described by S. Silver, in "Microwave Antenna Theory and Design", published in Section 8, pp. 246-247, MIT Radiation Laboratory Series, Boston Technical Lithographies, Inc., 1963.
The purpose of the balun 9 is to match the unbalanced coaxial line to the balanced dipole antenna. The modified balun device 9 is shown in FIG. 2 where the conventional "post" is replaced by the avalanche diode D2 of FIG. 1. The avalanche diode D2 is selected to avalanche at a critical threshold voltage generating about 1,000 volts, 100 ps rise time pulse. This high voltage, very fast rise time, pulse is directly incident on the input port of a dipole element collocated with the avalanche diode (i.e., "the post"). The balun 9 behaves properly as a microwave matching element during the pulse avalanche mode because diode D2 is a virtual short circuit when the avalanche diode is triggered having the same electrical properties of the post P.
The dipole 5 and 7 is placed above a flat plate to ensure radiation in the forward direction only as shown in FIG. 3. It may also be mounted within a corner reflector for greater gain at the cost of additional dispersion or for that matter other appropriately designed reflecting surfaces. The signal radiated into the far field as shown on a sampling oscilloscope is presented in FIG. 4. The signal is viewed by a dipole-corner reflector receiving antenna (with an actual post substituted for the avalanche diode in the balun) and is connected directly to a Hewlett-Packard model #181A/1811A sampling oscilloscope located at one meter from the source. The response contains only several cycles of S-band microwave energy even with the additional dispersion introduced by the receiving antenna as shown in FIG. 4.
The slots S shown in FIG. 2 are generally set to be equal to a quarter of a wavelength in length at the nominal center frequency of the pulse burst as are the element lengths (or wings) 5 and 7 which form the dipole. Both wings of the dipole are mounted on the outer conductor of the coaxial fixture 3 in which a pair of slots S are milled in plane normal to the dipole axis; the slot width is made much less than a wavelength. The inner conductor 11 of the coaxial feed line is short circuited to the outer conductor on one side of diode D2 as shown in FIG. 2.
Previous attempts to increase the prf of the source have been limited by avalanche transistor dissipation and power supply drain. To significantly increase the prf of the source beyond what has been achieved by other investigators, it is important to recognize the sources of current drain in the system.
At first inspection, it appears that the only source of current drain from the dc supply is due to the charging of the capacitors, C2, C3, C4 . . . Cn denoted as 470 pf in FIG. 1. Note that in the Marx generator design the capacitors are charged in parallel, and that the dissipation limitations of the avalanche transistors Q1, Q2, Q3, . . . Qn (e.g., a RS 3500 or the equivalent) determine the maximum prf. It can be shown mathematically that the average current during the charge cycle is determined only by the capacitor, Cn. The two charging resistor pairs (R5, R10; R6, R11; R12; etc.), shown as 6.8K in FIG. 1 should be made as small as possible to ensure recharging Cn, quickly for achieving a high prf. Since these resistors directly load the short pulse that is produced during the avalanche mode (e.g., they are effectively in parallel with the avalanche diode and balun circuit) they cannot be made too low in value. For example, in a 12 transistor Marx generator, there are effectively 24-6.8K resistors in parallel constituting about a 280 ohm load. This load is in parallel with the 50 ohm driving point impedance of the balun which results in a reduction of the high voltage signal incident on the avalanche diode. The decrease in output voltage can only be compensated for by increasing the number of avalanche transistor stages which, in turn, further increases the loading resulting in a vanishing small gain.
It was found, by experiment, that a major cause of power drain from the source and dissipation was due to the stored charge properties of the avalanche transistors themselves after they are activated. For example, the avalanche transistors continue to behave as a virtual short circuit for as much as 5 microseconds after it fires causing a large overage current to flow through the two 6.8K resistors. This leakage current is comparable to the charging current itself. In addition, when the avalanche transistor is "off" its static resistance is only 100K ohms (i.e., it is not an open circuit). If the supply voltage, for example, is 220 volts, then each avalanche transistor draws about 2.2 ma from the supply or a total of an additional 26 ma, statically, which is also comparable to the average capacitor charging current and directly affects avalanche transistor dissipation and limits the prf to a kHz or less.
To reduce dissipation significantly, the subject invention uses the gating scheme shown in FIG. 5. Briefly, the circuit assures that the capacitors are charged during a short interval before application of the main avalanche trigger. And, the power supply is disconnected just prior to triggering the Marx generator. In this manner, the shorted avalanche transistors which continues for about 5 microseconds after firing causes no drain on the supply and dissipation within the transistors because the battery is disconnected, (e.g., the capacitors discharge in nanoseconds into the antenna and there are no other sources of energy in the circuit). The leakage current and accompanying dissipation is reduced substantially because the supply is only connected when the capacitors charge (e.g., a fraction of the pulse repetition period).
An external trigger is applied at terminal 4 in series with a current limiting resistor 6. The trigger is applied to two monostable or one shot multivibrator networks 10 and 18 respectively, creating the gating sequency shown in FIG. 5a.
Referring to FIGS. 5a and 5b, one-shot 10 produces the pulse train Y when triggered by external trigger X. Assuming a pulse repetition period of 50 microseconds, the gate width of pulse train Y is set to 15 microseconds by the resistor 8 and the capacitor 45. This gate width of pulse train Y modulates the Vcc supply via a Field Effect Transistor (FET); i.e., a submodulator 40. The output signal C of submodulator 40 turns the power to the avalanche transistor generator 2, on and off. When output signal C is applied to generator 2, the capacitors Cn fully charge through the resistors Rm, Rm+5 (FIG. 1) and are shown as wave shape Y'. The capacitors Cn remain charged for a short time after the power is removed because there is virtually no discharge path.
The tailing edge of its waveform Y triggers one-shot 18 which generates a 100 nanosecond duration pulse Z. The pulse width is determined by a resistor 44 between pin 7 and +5 volts and a capacitor 16 across pins 6 and 7 of one-shot 18. A capacitor 42 is used for conventional bypassing of the +5 volt power supply. Pulse Z triggers a sampling oscilloscope at scope trigger 36. Pulse Z is also fed through a 120 nanosecond delay network made up of an invertor 12, a capacitor 46, a resistor 26, a diode 24, and an invertor 34. The invertors 12 and 34 are also used for isolation to produce the main drive transmitter pulse (trigger) A for input to generator 2. The trigger A is fed via drivers 28, 30 and 32 in parallel to create a low source impedance. When trigger A is applied to the avalanche generator 2, a 1200 volt, 100 picosecond rise time pulse B is generated. Pulse B excites antenna 36 producing the microwave S-band pulse burst R.
To estimate the current drain, assume a battery voltage of 220 volts and a pulse repetition period of 50 microseconds, the FET 40 off resistance of 1M ohms and a charge time of about 15 microseconds, then the leakage current is approximately given by: ##EQU1## During charge, the FET is on and the avalanche transistor is off, then ##EQU2## In addition to the leakage current, we have the normal charge current of ##EQU3## Thus, the total current, by superposition, is approximately
1.6+6.9+23˜30 ma (4)
Had the FET, with the subject invention's special gating features not been employed, the current drain would have been ##EQU4## For a total current, by superposition, of
23.2+19.4+23=65.6 ma (8)
This factor of 65.6/30=2.19 reduction in current corresponds to a factor of about 5 saving in dissipation (note: dissipation is a function of i 2 ).
In summary, the above calculation shows, by example, why the instant invention permits operation at a higher prf than previously achieved. The numbers become more dramatic if, for example, a higher "off" resistance FET is used for gating off the supply and the required charge time is further reduced by the use of active circuits. Or the dissipation is farther reduced if the prf is lowered; for example, to 10 kHz.
Also, the use of a slotted balun and dipole antenna configuration replacing the conventional post location by an avalanche diode (e.g., a type IN 5400 or the equivalent) permits radiation of a very fast rise time pulse (i.e., by producing a good "match") and high peak power with significant radiation at S-band of 10 volts peak to peak one meter from the source as measured on the reference receive element (e.g., 2.5 GHz). The amplitude of the radiated pulse depends on the snap speed of the diode and the frequency to which the balun-dipole configuration is tuned. It should be possible to radiate using a simple dipole element up to 5 GHz. By placing the avalanche diode D2, for example, in a waveguide, radiation at X-band is feasible, but at reduced field strength.
It is also possible to use an array of these sources synchronized with the referenced application to focus short pulse microwave energy in the far field and steer the beam in space by appropriately controlling the time delay of the trigger to each Marx generator described in this application. The instant invention then becomes an "element in an array and provides the basis for a very low-cost scheme for beam formation and steering.
While the invention has been shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that the above and other changes in form and detail may be made therein without departing from the spirit and scope of the invention.
|
This invention describes a high voltage, very short pulse, microwave radiating source using low-cost components, and capable of operating at high pulse repetition frequencies (prf). The source is activated by an ordinary video trigger commensurate with driving TTL logic. A trigger will cause a chain of N (where N may be 12 or greater) avalanche transistors connected in a Marx generator configuration to threshold resulting in a 1,200 volt or greater baseband pulse having a rise time of less than 100 ps and a duration of about 3 ns driving the input port of a dipole antenna. The dipole is excited by a balun. This invention achieves very short pulse duration broadband microwave radiation at pulse repetition frequencies as high as 30 kHz or greater.
| 7
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an oil passage usable for an engine and more particularly to an oil passage usable for an engine, particularly, a four cycle internal combustion engine by way of which oil used in the interior of the cylinder head is smoothly returned to the crankcase.
2. Description of the Prior Art
As is hitherto known, oil supplied into the interior of the cylinder head is generally returned to the crankcase via a cam chain chamber formed in the cylinder block, stud bolt insert holes and the hollow space of the cylinder block after it lubricates operative parts in the valve actuating mechanism or the like arranged in the cylinder head or it cools them.
However, it has been pointed out as a drawback inherent to the conventional engine that oil is stirred by means of endless cam chain during returning to the crankcase via the cam chain chamber which constitutes a part of oil passage, resulting in air being entrapped in oil. Further, it has been found that as oil is scattered by means of the cam chain, a part of thus scattered oil is deposited on the valve actuating mechanism, causing an occurrence of mechanical loss relative to the latter, and another part of scattered oil is carried away together with blow-by gas, resulting in increased consumption of oil.
On the other hand, in the case where oil passage is constituted by a plurality of stud bolt insert holes there occurs a problem that a volume of oil to be returned is restricted because the diameter of insert holes can not be enlarged due to the geometrical configuration of the cylinder head and this leads to smooth returning of used oil to the crankcase being achieved only with much difficulties.
SUMMARY OF THE INVENTION
Hence, the present invention has been made with the foregoing backgrounds in mind and its object resides in providing an oil passage usable for an engine which assures that oil fed to the cylinder head is smoothly returned to the oil pan at an increased rate of flow and moreover an occurrence of air entrapping, mechanical loss caused by scattering of oil and increased consumption of oil are minimized.
Other object of the present invention is to provide an oil passage usable for an engine which assures that used oil to be returned is cooled by counterflowing air stream which is developed during running of a motorcycle without any deterioration of characteristics of oil.
To accomplish the above object there is proposed according to the present invention an oil passage usable for an engine, particularly, an internal combustion engine which is characterized in that at least one hydraulic communication means in the form of tube is disposed at the position located outwardly of the cylinder block of the engine so as to establish hydraulic communication between the cylinder head and the oil pan whereby oil fed to the cylinder head is returned to the oil pan through the hydraulic communication means.
In a preferred embodiment of the invention at least one main discharging passage is formed at the position located in the side part of the cylinder head and the one end of the hydraulic communication means is fitted to the main discharging passage.
Other objects, features and advantages of the present invention will become readily apparent from reading of the following description which has bcen prepared in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings will be briefly described below.
FIG. 1 is a partially sectioned side view of an engine with an oil passage of the invention attached thereto.
FIG. 2 is a plan view of the cylinder head with the oil passage of the invention incorporated therein, as seen from the above.
FIG. 3 is a plan view of the cylinder head in FIG. 2, as seen from the below.
FIG. 4 is a partially sectioned front view of the cylinder head in FIG. 2.
FIG. 5 is an enlarged plan view of a cover to be fitted to the cylinder head.
FIG. 6 is a plan view of the right half of the cylinder head with the cover fitted thereto, as seen from the above.
FIG. 7 is an enlarges plan view of a valve spring seat.
FIG. 8 is a side view of the valve spring seat in FIG. 7.
FIG. 9 is a plan view of the right half of the cylinder head with the valve spring seat attached thereto, as seen from the above.
FIG. 10 is a plan view of the cylinder head cover, as seen from the above.
FIG. 11 is a plan view of the cylinder head cover in FIG. 10, as seen from the below.
FIG. 12 is a fragmental vertical sectional view of the right half of the cylinder head with the cylinder head cover firmly mounted thereon.
FIG. 13 is a vertical sectional view of the combination of cylinder head and cylinder head cover, taken in line D--D in FIG. 12.
FIG. 14 is a partially sectioned perspective view of a cylinder head fastening bolt, shown in an enlarged scale.
FIG. 15 is a fragmental vertical sectional view of the right half of the cylinder head, particularly illustrating how each of the recesses has a rugged bottom surface, and
FIG. 16 is a fragmental plan view of the cylinder head in FIG. 15, particularly illustrating how a number of ridge lines on the recesses extend.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, the present invention will be described in a greater detail hereunder with reference to the accompanying drawings which illustrate an apparatus according to preferred embodiments thereof.
FIGS. 2 and 3 are a plan view of a cylinder head 10 as seen from the above and the below respectively, in which oil passages according to the present invention are employed for the cylinder head 10, particularly for cylinder head used for a double overhead camshaft type engine preferably mounted on motorcycle.
As shown in FIG. 2, the cylinder head 10 is provided with bearing portions 12 and 14 for cam shafts (not shown) adapted to drive rocker arms. Specifically, the bearing portions 12 are located on the exhaust side (as identified by an arrow mark A), while the bearing portions 14 are located on the inlet port side (as identified by an arrow mark B). Further, the cylinder head 10 is provided with other bearing portions for rocker shafts (not shown) adapted to turnably support rocker arms on both the exhaust and inlet sides at the position located below the bearing portions 12 and 14.
As is apparent from FIG. 2, a plurality of lubricating oil spouting holes 16 through which pressurized lubricating oil (hereinafter referred to simply as oil) is pumped up via oil galleries (not shown) formed in the cylinder head 10 are disposed at the position located in the vicinity of the bearing portions 12 and 14.
Referring to FIG. 2 again, a plurality of recesses 20, 22, 24, 26, 28 and 30 are formed in the area extending in the longitudinal direction on the middle part of the inner surface of the cylinder head 10. Specifically, the recesses 20, 22, 24, 26, 28 and 30 are disposed at the position located approximately above combustion chambers 32, 34, 36 and 38 as illustrated in FIG. 3. Further, referring to FIG. 4 which is a partially sectioned front view of the cylinder head 10, the recesses 20, 22, 24, 26, 28 and 30 are formed in the area including the space as defined by the bore diameter of the combustion chambers 32, 34, 36 and 38 (but excluding the area occupied by cylindrical bosses 40, 42, 44 and 46 for mounting ignition plugs, the cylindrical bosses 40, 42, 44 and 46 being located above the central part of the combustion chambers 32, 34, 36 and 38). Thus, as shown in FIG. 2, the peripheral walls 20a, 22a, 24a, 26a, 28a and 30a of the recesses 20, 22, 24, 26, 28 and 30 are located adjacent to the peripheral walls of valve seats 50 for supporting exhaust valves and valve seats 52 for supporting inlet valves and moreover, as shown in FIG. 4, they are located adjacent to the peripheral walls of the ignition plug seats 54 provided for the combustion chambers 32, 34, 36 and 38. As oil is supplied into the recesses 20, 22, 24, 26, 28 and 30 formed in the above-described manner by an injection from oil feeding passages which will be described later, it is increasingly accumulated in each of the recesses 20, 22, 24, 26, 28 and 30 and a thermal boundary layer between each of the recesses and thus accumulated oil is then disturbed or broken whereby heat transmitted from the combustion chambers 32, 34, 36 and 38 (see FIG. 3), the valve seats 50 and 52 and the ignition plug seats 54 is absorbed by thus accumulated oil, resulting in the major part of the cylinder head 10 being cooled sufficiently. On the other hands, as shown in FIG. 2, the peripheral walls 20a, 22a, 24a, 26a, 28a and 30a of the recesses 20, 22, 24, 26, 28 and 30 are formed with a plurality of oil discharging holes 60, 62, 64, 66, 68, 70, 72 and 74 through which an excessive amount of oil accumulated in the recesses 20, 22, 24, 26, 28 and 30 is discharged continuously. Among them the oil discharging holes 60, 66, 68 and 74 in the recesses 20, 24, 26 and 30 formed at both the lefthand and righthand end parts of the cylinder head 10, as well as at the position located opposite to one another relative to a cam chain chamber 90', are communicated with stud bolt insert holes 90, 92, 94 and 96 via oil discharging passages 80, 82, 84 and 86. Accordingly, oil in the recesses 20, 24, 26 and 30 is caused to flow into the insert holes 90, 92, 94 and 96 through the discharging holes 60, 66, 68 and 74 and the discharging passages 80, 82, 84 and 86 and thereafter it is returned to an oil pan on the engine via the insert holes 90, 92, 94 and 96. On the other hands, the discharging holes 62, 64, 70 and 72 in the recesses 22 and 28 are communicated with main discharging passages 110 and 112 formed on the exhaust ports side via discharging passages 100, 102, 104 and 106. As illustrated in FIG. 4, the main discharging passages 110 and 112 are formed at the position located between the adjacent exhaust ports on the outer surface of the cylinder head 10. The discharging passages 100, 102, 104 and 106 are formed at the position located adjacent to the wall surface of the exhaust ports in the cylinder head 10. Owing to the arrangement made in that way heat developed in the exhaust ports is absorbed by oil in the recesses 22 and 28 while it is discharged into the main discharging passages 110 and 112 via the discharging passages 100, 102, 104 and 106 whereby the exhaust ports are cooled satisfactorily.
In addition to the discharging passages 100, 102, 104 and 106 which are in communication with the recesses 22 and 28 the main discharging passages 110 and 112 are communicated with discharging passages 132, 134, 136, 138, 140 and 142 which include openings 120, 122, 124, 126, 128 and 130 on the inner surface of the cylinder head 10, causing oil flowing in the area located above the exhaust ports in the cylinder head 10 to be discharged into the main discharging passages 110 and 112 via the discharging passages 132, 134, 136, 138 and 140. Incidentally, in FIG. 2 reference numerals 150, 152, 154, 156, 158, 160, 162 and 164 designate stud bolt insert holes through which a stud bolt (not shown) is inserted, and reference numerals 170, 172, 174 and 176 identify a flange portion on the top of the ignition plug mounting bosses 40, 42, 44 and 46, respectively. Each of the flange portions 170, 172, 174 and 176 is formed with a hole 180 which constitutes a part of oil feeding passage to be described later through which oil is fed into the recesses 20, 22, 24, 26, 28 and 30. Further, in FIG. 3 reference numerals 190, 192, 194 and 196 designates a hole respectively, which is formed at the position located below the exhaust ports 50', 52', 54' and 65'. The holes 190, 192, 194 and 196 are communicated with the interior of the ignition plug mounting bosses 40, 42, 44 and 46 as shown in FIG. 2. Referring to FIGS. 4 and 2 again, reference numerals 210, 212, 214, 216, 218 and 220 designate a boss standing upright in the recesses 20, 22, 24, 26, 28 and 30 respectively. The bosses 210, 212, 214, 216, 218 and 220 are formed with female threads 210a, 212a, 214a, 216a, 218a and 220a (see FIG. 2). The female threads 210a, 212a, 214a, 216a, 218a and 220a are adapted to function as female portions for fastening a plate-shaped cover 230 as shown in FIG. 5 in an enlarged scale. The configuration of the cover 230 is designed to independently cover the lefthand area as defined by the group of recesses 20, 22 and 24 and the righthand area as defined by the group of recesses 26, 28 and 30, both the areas being located symmetrical relative to the cam chain chamber 90' as seen in FIG. 2. Incidentally, the cover 230 has the inverted U-shaped cross-sectional configuration in order to assure increased mechanical strength. Further, the cover 230 is formed with fitting bolt insert holes 232 and pipe fitting holes 234 through which a pipe constituting oil feeding passage to be described later is inserted. Thus, when the thus designed covers 230 are assembled on the cylinder head 10 as illustrated in FIG. 2, all the recesses 20, 22, 24, 26, 28 and 30 are covered with them, as shown in FIG. 1 which is an enlarged partial plan view of the cylinder head 10. Once the recesses 20, 22, 24, 26, 28 and 30 are covered with the cover 230 in that way, it is assured that oil held in them is inhibited from being scattered inwardly of the cylinder head 10. In FIG. 6 reference numerals 240 designate a fitting bolt respectively, by means of which the covers 230 are fastened to the cylinder head 10. Further, in order to inhibit an excessive amount of oil from being deposited on exhaust valves, valve springs or the likes, plate-shaped seats 250 are fastened to the cylinder head 10, as shown in FIG. 7 which is an enlarged plan view of the valve spring seat and FIG. 8 which is a side view of the same. As is apparent from FIG. 6, each of the valve spring seats 250 is formed with a plurality of valve guide insert holes 252 and it has the L-shaped cross-sectional configuration so as to assure increased mechanical strength. FIG. 9 is a partial plan view particularly illustrating how the valve spring seats 250 are fastened to the inside of the cylinder head 10 and same parts as those in FIGS. 2 and 6 are identified by same reference numerals. It should be noted that the valve spring seat 250 is immovably held on the valve seat by means of valve springs (not shown) in such a manner that a plurality of valve guides are simultaneously fitted through a single sheet of plate, resulting in any occurrence of underdesirable turning movement of the valve spring seat as is seen with the conventional circular disc-shaped valve seat being prevented.
Next, description will be made in more details as to the oil feeding passages through which oil is fed to the recesses 20, 22, 24, 26, 28 and 30 on the cylinder head 10.
FIGS. 10 and 11 are a plan view of a cylinder head cover 260 as seen from the above and below respectively, with which the cylinder head 10 as shown in FIG. 2 is covered.
The cylinder head cover 260 is designed in the plate-shaped configuration so as to fully cover the whole surface of the cylinder head 10 and it is formed with an opening 262 at the central part thereof through which blow-by gas is taken out. Further, it is formed with a plurality of insert holes 270, 272, 274 and 276 through which ignition plugs and ignition plug fitting and removing tools are inserted, the insert holes 270, 272, 274 and 276 being arranged at the central part thereof as seen in the longitudinal direction on the drawings. Incidentally, inclined guide grooves 270a, 272a, 274a and 276a are formed on the inner wall of the insert holes 270, 272, 274 and 276. As shown in FIG. 11, oil feeding passages 280 and 282 through which oil pumped up from an oil supply source (not shown) is introduced into the central part of the cylinder head cover 260 are formed on the bottom surface of the head cover 260. The one ends of the oil feeding passages 280 and 282 are communicated with feeding ports 290 and 292 on the inlet port side of the cylinder head cover 260, whereas the other ends of the same are branched to reach flange portions 270b, 272b, 274b and 276b on the insert holes 270, 272, 274 and 276. The flange portions 270b, 272b, 274b and 276b have insert holes 310, 312, 314, 316, 318, 320, 322 and 324 formed thereon through which fastening bolts (which will be described later) for immovably fastening the cylinder head cover 260 to the cylinder head (see FIG. 2) are inserted and the other ends of the branched parts of the oil feeding passages 280 and 282 are communicated with the insert holes 310, 312, 314, 316, 318, 320, 322 and 324. Owing to the arrangement made in that way, as oil is fed through the feeding ports 290 and 292 as represented by arrow marks on the drawing, it flows in the oil feeding passages 280 and 282 to reach the insert holes 310, 312, 314, 316, 318, 320, 322 and 324. It should be noted that the insert holes 310, 312, 314, 316, 318, 320, 322 and 324 are located opposite to the holes 180 on the flange portions 170, 172, 174 and 176 of the bosses 40, 42, 44 and 46. Incidentally, in FIGS. 10 and 11 reference numerals 330 designate an insert hole respectively, through which a fastening bolt is inserted to immovably fasten the cylinder head cover 260 to the cylinder head 10 (see FIG. 2). After oil reaches the insert holes 310, 312, 314, 316, 318, 320, 322 and 324 on the cylinder head cover 260, it flows through oil passages 342 formed in the fastening bolts 340 and pipes 344 fitted into the holes 180 on the flange portions 170, 172, 174 and 176 as shown in FIG. 12 which is an enlarged fragmental sectional view of the cylinder head cover 260 fastened to the cylinder head 10 and FIG. 13 which is a cross-sectional view of the cylinder head 10 and the cylinder head cover 260 taken in line D--D in FIG. 12. Thereafter, it is supplied into each of the recesses 20, 22, 24, 26, 28 and 30 on the cylinder head 10. As mentioned above, in the embodiment as illustrated in FIG. 13 oil is introduced into the recesses 20, 22, 24, 26, 28 and 30 via the holes 180 on the flange portions 170, 172, 174 and 176 and the pipes 344 but the present invention should not be limited only to this. Alternatively, arrangement may be made such that the flange portions 170, 172, 174 and 176 are extended until they reach the recesses 20, 22, 24, 26, 28 and 30 and an oil passage is drilled through each of the flange portions 170, 172, 174 and 176 without any use of pipes such as the pipes 344. In the case of a fastening bolt 340 as illustrated in FIG. 14 by way of enlarged sectional perspective view it is formed with a T-shaped oil passage 342 so that oil is introduced toward the lowermost end through the oil passage 342 after entrance from the peripheral surface 340a of the bolt 340 as represented by arrow marks. Incidentally, parts in FIGS. 12 and 13 as those in FIGS. 2, 4, 6, 9 and 11 are identified by same reference numerals. After oil is supplied into each of the recesses 20, 22, 24, 26, 28 and 30 on the cylinder head 10, it is discharged into the insert holes 90, 92, 94 and 96 or the main discharging passages 110 and 112 via the discharging holes 60, 62, 64, 66, 68, 70, 72 and 74 (see FIG. 2) on the peripheral walls 20a, 22a, 24a, 26a, 28a and 30a of the recesses 20, 22, 24, 26, 28 and 30.
It should be noted that an engine mounted on motorcycle is usually mounted thereon in the forwardly inclined posture as seen in the direction of running due to a requirement for reducing the height of the body as far as possible. For the reason the cylinder head 10 is held in such an inclined state that the exhaust port side is lowered as represented by a horizontal line E--E in FIG. 13 whereby oil discharged into the cylinder block after slidable components such as cam shafts or the like are lubricated properly is caused to flow into the discharging holes 120, 122, 124, 126, 128 and 130 as shown in FIG. 2 in the same manner as oil temporarily accumulated in the recesses and thereafter it is discharged into the main discharging passages 110 and 112 via the discharging holes.
In the above-described embodiment each of the recesses 20, 22, 24, 26, 28 and 30 has a flat bottom surface 400 which extends substantially in parallel with the upper surface of the associated combustion chamber, as shown in FIG. 4. However, the present invention should not be limited only to this. Alternatively, each of the recesses 20, 22, 24, 26, 28 and 30 may have a rugged bottom surface in order to increase contact area over which oil temporarily accumulated in the recess comes in surface contact with the associated bottom surface 400 and thereby assure increased cooling effect in the presence of oil, as shown in FIG. 15 which is a fragmental enlarged vertical sectional view. Also in this embodiment same parts as those in FIG. 4 are identified by same reference numerals. In addition to this a number of ridge lines on the rugged bottom surface may have specific directional configuration, as shown in FIG. 16 which is a fragmental plan view of FIG. 15. This embodiment is intended to allow oil to smoothly flow toward the discharging holes.
As will be apparent from FIG. 1 which schematically illustrates an engine 500 by way of side view, oil is returned into the interior of a crankcase 504 via the main discharging passages 110 and 112 on the cylinder head 10 and the oil passages 600 of the invention which are provided independently of the cylinder block 502.
Specifically, each of the oil passages 600 is constituted by a combination of pipe 602 of which upper end is fitted to the main discharging passage 110 and oil passage 506 formed in the crankcase 504. Incidentally, things are same with the main discharging passage 112 which is not shown in FIG. 1. Namely, arrangement is made such that the oil passage on the side wall of the cylinder block 502 is communicated with the oil passage in the crankcase 504. Owing to the arrangement made in that way almost of oil which has been fed to the cylinder head 10 is returned to the interior of the crankcase via the main discharging passages 110 and 112 and the pipes 602. As is apparent from FIG. 1, another pipe 508 is fitted into the other end of each of the oil passages 506 and the other end 508a of the pipe 508 is located at the position in the proximity of the oil pan 510. Thus, oil discharged through the oil passage 514 by way of which the crankcase 512 is communicated with the oil pan 510 and oil returned to the oil pan 510 from the cylinder head 10 via the oil passages of the invention are smoothly discharged into the interior of the oil pan 510 without any occurrence of interference therebetween. The fitting part where the pipe 602 is fitted into the main discharging passage 110 and the fitting part where the pipe 602 is fitted into the oil passage 506 in the crankcase 504 are equipped with a sealing member such as O-ring or the like means whereby the pipe 602 is leaklessly communicated with the passages 110 and 506. In the case where openings through which cooling air is introduced are formed at the position located between the adjacent cylinder chambers it should of course be understood that care should be taken so as not to allow each of the pipes 602 to assume the position in front of the opening.
As will be obvious for any expert in the art, various changes or modifications may be made for the invention in any acceptable manner without departure from the spirit and scope of the invention. Accordingly, it should be considered that the above-described embodiments are merely illustrative and therefore they should not be interpreted limitatively. After all, the scope of the invention is as defined by the claim clause without any restriction or limitation being effected by the description of the specification. Finally, it should be understood that all changes or modifications falling under scope of the claim clause should be construed within the scope of the invention.
|
An oil passage comprising at least one hydraulic communication means in the form of pipe which is disposed at the position located outwardly of the cylinder block of an engine so as to establish hydraulic communication between the cylinder head and the oil pan. Oil fed in the interior of the cylinder head is returned to the oil pan by way of the hydraulic communication means.
| 5
|
BACKGROUND OF THE INVENTION
The present invention relates to methods used in containing and removing leaked and spilled hydrocarbons in the marine environment.
For marine vessel fueling facilities, there is a need to remove hydrocarbons spilled or leaked on to the surface of the water as part of routine fueling operations of vessels. Spills of this nature are generated by fuel being forced out of the ventilation valve of the fuel tank of the vessel and on to the surface of the water when the fuel tank is filled to capacity. Spills also occur when fuel overflows from the fuel tank intake port of the vessel and on to the surface of the water when the fuel tank is filled to capacity during fueling operations. The task of containing these spills is necessary to prevent the hydrocarbons that are spilled or leaked on the surface of the water from spreading throughout the fueling facility area, allowing them to flow out of the containment area and polluting the adjacent waterways.
The most common method of eliminating the sheen on the water caused by these spills is to pour a dispersant such as liquid dishwashing soap on the spill. The dispersant breaks up the oily sheen into tiny particles of hydrocarbon that remain in the water and are not visible to the eye unless they are magnified. This "out of sight, out of mind" mentality is by far the most prevalent treatment of spills generated at marine fueling facilities. The use of a dispersant in this manner currently violates a number of regulations and statutes with regard to the use of dispersants in the handling of spills of this nature.
Seldom is an effort made to extract the pollutants from the surface of the water, leaving the hydrocarbons on the water to spread throughout the adjacent waterway, polluting the environment.
The prior art method of dealing with hydrocarbon spills at marine fueling facilities is extremely harmful to the marine environment immediately surrounding the fueling facility as well as posing a variety of health and safety hazards. The placement of a liquid detergent on the surface of the water to disperse the sheen does not remove the hydrocarbons from the water, it merely removes the telltale sheen from sight. The pollutants are never extracted from the water, leaving them to contaminate the area adjacent to the fueling facility. Marinelife and wildlife are effected by the pollution. The accumulation of hydrocarbons on the surface of the water renders the water unfit for drinking or swimming and presents a safety hazard. The presence of the hydrocarbon pollutants floating freely on the surface of the water creates an even greater fire hazard than that which already exists due to the handling of flammable liquids at the fueling facility. The free release of pollutants into the marine environment at marine fueling facilities poses a number of concerns that are not addressed using the present method of eliminating the sheen from the surface of the water at these facilities.
Another common approach to removing the hydrocarbon spills from the surface of the water is to use absorbent devices, typically made of a non-woven, synthetic fabric such as polypropylene, polyester or nylon. Such fabrics are petro-chemical based materials having the physical properties of absorbing liquid hydrocarbons while repelling water. These materials can be used as flat pads or sheets, rolled into long cylindrical booms or packaged in an open weave plastic net to form a sausage-like boom.
The use of absorbent devices for removing spills from the surface of the water often results in the transfer of the liquid hydrocarbon pollutants from one environment to another since the absorbent devices are subject to having the sorbed hydrocarbons released by gravity, column weight and outside forces exerting pressure on them when they are removed from the spill area. The released liquid hydrocarbons are then free to seep through the ground and enter the adjacent water column or flow downstream as waste water runoff.
SUMMARY OF THE INVENTION
In accordance with the present invention, a method of employing absorbent devices is provided which will contain and prevent the spread of hydrocarbon spills on the surface of the water in marine fueling facilities. The absorbent devices used in the system not only absorb liquid hydrocarbons, but also quickly and irreversibly solidify the absorbed liquid hydrocarbons into an easily retrievable, solid rubber-like mass. The solidified hydrocarbons will not leech when exposed to pressure limits used to determine landfill suitability. The solidified devices can be disposed of as landfill, incinerated as a fuel or utilized as a component in the production of asphalt or other paving compounds.
The device is formed as a pillow from a textile material sewn to form layered chambers in stratification contained within an outer envelope layer which defines the overall pillow shape. A length of rope is sewn into one of the sides of the outer envelope, creating a boltrope effect similar to that used in the production of sails. The boltrope is incorporated in a method of attaching the pillows to the docks and piers of the fueling facility.
A seam is placed longitudinally along the center axis of the pillow, creating two columns of stratified pockets. Additional cross-seams are placed at evenly spaced intervals laterally from one side of the pillow to the opposite side of the pillow, crossing the center axis seam of the pillow in a perpendicular or an oblique orientation to the center axis of the pillow. This seaming results in a quilting effect which produces a calculated number and arrangement of chambers containing an approximately equal amount of solidifying polymer. The design and spacing of the seams creates multiple consolidation points of the stratified layers. These consolidation points define the multiple compartmented absorption cells and act as flow channels to facilitate and hasten the migration of the spill or leak to the solidifying polymer in the compartmented absorption cells, followed by the complete absorption and solidification of the spill or leak.
The seaming of the textile material components of the device can be accomplished by a variety of methods that include mechanical stitching, thermal sealing and ultra-sonic fusing. These seaming methods are used to seal the perimeter of the pillow, produce the individual chambers of solidifying polymer and unite the stratified internal layers with the outer envelope. The joining of the layers of textile material results in a series of consolidation points of the layers of textile material and creates the flow channels throughout the body of the pillow for the migration of spills and leaks to the absorptive cells within the pillow.
The solidifying polymer can be placed in the pillow using any of several different methods. As a first example, the polymer, in its granular form, can be placed in equally measured amounts, into the open end of the pillow after three sides of the pillow have been seamed and the center longitudinal axis seam has been placed to form side-by-side elongated pockets. The inserted polymer collects at the bottom of the pocket and a cross-seam is placed to form a polymer-filled chamber. The step of introducing polymer into the open end of the pillow, then sealing it into the chambers by placing a cross-seam is repeated until all the stratified chambers have been formed to create a matrix arrangement of polymer-filled chambers stratified within the outer envelope of the pillow. The seaming to form the matrix of chambers also acts to provide the quilting effect desired for increasing the rate of migration of the hydrocarbons to the interior of the pillow by the creation of consolidation points and flow channels.
Other methods of stratifying and sealing the solidifying polymer within the outer envelope of the device can be used. One method calls for the solidifying polymer to be encased and sealed within individual bags of single layer textile material, these bags being filled and sealed in an assembly-line fashion. Each bag, filled with a measured amount of the solidifying polymer is sealed to form a solitary chamber of solidifying polymer within a single layer of textile material. Individual bags are then arranged side-by-side in a matrix configuration of rows and columns to produce a single layer of bags conforming to the designated perimeter dimensions of the finished pillow. Identical layers of the arrangement of polymer-filled bags are duplicated and then stratified over the first layer of bags to produce the required thickness of the pillow. Each layer of the arrangement of bags is positioned so the perimeter of the overall shape of the layer and the side-by-side intersections of the matrix of bags in each layer are aligned in substantial registration with the corresponding perimeter of the arrangement of bags and the side-by-side intersections of the arranged bags of the other layers. The stratified layers of individual polymer-filled bags are then enclosed within an outer envelope of textile material and sealed within the perimeter of the outer envelope. The intersections of the individual polymer-filled bags of the stratified layers are seamed to the outer envelope of the pillow, creating the longitudinal and cross-seams of the pillow used as flow channels and consolidating points of the stratified layers. The result is the required quilting effect integral to the concept.
The solidifying polymer can also be suspended within the fibers of a textile material as they are being formed, or attached to the textile material. The suspending of the polymer is accomplished by incorporating the polymer into the body of the fabric during the process used to form the textile material. This process is normally used in the production of melt-blown or spunbonded textiles.
The manufacturing of a synthetic textile fabric material starts with raw petro-chemical based pellets, such as polypropylene, being blended with pigments and/or additives. This mixture is heated to the melting point of the pellets and extruded into filaments. The filaments are drawn and attenuated, using high velocity air to align the polymer molecules and maximize fiber strength. The resulting continuous, high tenacity filaments are formed into a web on a moving conveyor screen and thermally fused together with a bonding system to maximize the strength and surface stability of the fabric.
One method of suspending the solidifying polymer within the fabric is accomplished by adding it to the mix of raw petro-chemical based pellets, pigments and additives, melting the mixture and extruding filaments from the mixture. This method incorporates the polymer into the body of the filaments as they are formed.
The solidifying polymer is also suspended within the fabric by injecting an evenly distributed amount of the polymer into the web of filaments at an intermediate point on the moving conveyor screen as the filaments are formed into a web. As the filaments are thermally bonded into a piece of fabric, the solidifying polymer is trapped within the web of filaments, becoming a component of the finished textile fabric material.
The solidifying polymer can also be attached to the textile material by using an adhesive to bond an evenly distributed, measured amount of the polymer to a layer of textile material.
Certain re-cycled plastic materials can be mixed with the pellets, pigments and additive components that form the filaments of the textile material, utilizing the re-cycled plastic components in an effective pollution control device and eliminating them from landfill disposal.
The textile material, holding the polymer within its web of filaments or bonded to the polymer with an adhesive, are stratified in layers between two layers of textile material that form the outer envelope of the pillow and seamed within the periphery of the outer envelope of the pillow. Longitudinal and lateral seams are then added to the pillow to produce the desired quilting effect.
In each instance, the solidifying polymer is stratified and arranged between layers of textile material within the pillow formed by the outer envelope, with additional seams providing a quilting effect for the entire pillow.
The quilting of the pillow creates a series of continuous consolidation points of the internally stratified layers of textile material within the pillow envelope. The textile material absorbs the spilled or leaked liquid hydrocarbons on contact. This action, coupled with the continuous consolidation points of the internal and external layers of textile material and the unique stratification design of the chambered pillow speeds migration of the liquid hydrocarbons through the flow channels created by the quilting seams throughout the interior of the pillow via the capillary attraction of the liquid hydrocarbons to the textile material. The result is a uniform distribution of the liquid hydrocarbons throughout the entire structure of the pillow for absorption and solidification of the liquid hydrocarbons by the alternating layers of solidifying polymer within the stratified layers of the pillow.
Typically, the density and weight of the internal layers of stratified, textile material is substantially less than the density and weight of the textile material used to form the outer envelope of the pillow. This is done to reduce the volume of liquid hydrocarbons that may be retained within the textile material segments of the pillow in the event the volume of the spill the pillow is being used to sorb is in excess of the capacity of the solidifying polymer within the pillow. Pillows fabricated of thinner textile materials of less dense construction characteristically retain a smaller volume of liquid hydrocarbons within the textile material components of the pillow than pillows fabricated using heavier textile materials of greater density.
Chemical composition, thickness and density of the fibers utilized in the composition of a textile material play a critically governing role in controlling the rate of absorption and the ratio of retention of the liquid hydrocarbons being sorbed by the material. Textile materials formed by using a greater density of thicker fibers are sturdier, more resistant to tearing and will sorb and retain greater volumes of liquid hydrocarbons than textile materials composed of thinner fibers or formed in a less dense configuration. Thus, a heavier material is used for the outer envelope to add to the structural integrity and durability of the envelope while lighter textile material is used internally to form the stratified chambers of solidifying polymer. The migration of the sorbed liquid hydrocarbons throughout the interior of the pillow via the capillary attraction of the liquid hydrocarbons to the textile material remains a characteristic of the device, while the level of retention of the liquid hydrocarbons by the textile material diminishes.
The pillows are held in place along the dock of a fueling facility in a horizontal orientation. This results in a vessel moored at a dock to be fueled to be bordered by a system of absorbing and solidifying devices to contain and solidify any hydrocarbons spilled on to the surface of the water during the fueling operation. The pillows are attached to the edge of the fuel dock using a length of boltrope incorporated into the body of the pillows during their fabrication and a length of extrusion attached in a horizontal orientation to the side of the fuel dock at water level.
The extrusion is attached to the dock of the floating fueling facility using adhesives and/or metal fasteners to keep the channel of the extrusion in place in a parallel, horizontal orientation at the surface of the water.
The boltrope is sewn into the outer envelope of the pillow. The rope portion of the boltrope is placed in the fold of the non-woven fabric comprising the outer envelope, where it is seamed tightly into the fold of the non-woven fabric. This results in the boltrope section of the pillow having a greater diameter than the seam between the boltrope and the body of the pillow. The greater diameter of the boltrope causes the pillow to be held in place when the boltrope is placed in the channel of the extrusion while the smaller diameter of the seam between the boltrope and the body of the pillow extends through the open slit that runs the entire length of the extrusion. The boltrope will not pass through the open slit in the extrusion due to its diameter being greater than the width of the slit in the extrusion.
One end of the boltrope is placed in the open channel at the end of the extrusion, where the male cross-section of the boltrope slides through the female cross-section of the extrusion channel while the seamed area of the pillow adjacent to the boltrope is simultaneously inserted in the slit at the end of the extrusion. The pillow is slid horizontally through the extrusion with the boltrope passing through the channel extrusion and seamed area of the pillow passing through the slit of the extrusion.
Additional pillows with boltrope sewn into one side are added in a similar manner until the full length of the extrusion has pillows floating on the surface of the water along the dock of the fueling facility. Pillows held in place by the extrusion are joined in an end-to-end orientation by utilizing the grommets on each end of the pillows to prevent any gaps that may form between them. Such gaps could allow spilled or leaked hydrocarbons to flow out of the containment system.
A barrier boom of pillows, joined end-to-end and of sufficient length to surround all portions of the vessel to be fueled that are not bordered by the dock of the fueling facility, can be pulled across the surface of the water and attached to the ends of the dock, thereby completely surrounding the vessel prior to commencing fueling operations. Any hydrocarbons spilled on to the surface of the water can be "herded" to the perimeter of the barrier boom using a stream of water to propel the spill into the pillows where it can be absorbed and solidified. The portion of the barrier boom not attached to the dock area can then be retracted to allow the vessel to depart the fueling facility.
Solidified pillows can be easily extracted from the fueling area and fresh, non-sorbed pillows put in their place. Replacing the solidified pillows removes the spilled hydrocarbons from the of the water. The solidified devices can be disposed of as landfill, incinerated as a fuel or utilized as a component in the production of asphalt or other paving compounds.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the preferred embodiments of the invention in which:
FIG. 1 is a top view of the device in accordance with the present invention;
FIG. 2 is an exploded illustration of the first embodiment of the device;
FIG. 3 shows the detail of the overlock seam;
FIG. 4 shows the detail of the seam used to consolidate the internally stratified layers of textile material with the outer envelope of the device in FIG. 2;
FIG. 5 shows a cross section of the first embodiment of the device;
FIG. 6 is an exploded illustration of a second embodiment of the device;
FIG. 7 shows a series of polymer-filled and sealed bags;
FIG. 8 shows a cross section of the second embodiment of the device;
FIG. 9 is an exploded illustration a third embodiment of the device;
FIG. 10 shows a cross section of the third embodiment of the device.
FIG. 11 shows a cross-section of the extrusion;
FIG. 12 shows an oblique view of the pillow being held in place by the extrusion; and
FIG. 13 shows a vessel in a fueling slip.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1, an absorbent device 1 in accordance with the present invention is shown in a pillow-shaped configuration formed by an envelope 2 with seaming of the four sides 2a, 2b, 2c, and 2d. This seam is shown in greater detail in FIG. 3. A length of rope is sewn into the outer envelope along the entire length of side 2a, creating a length of boltrope 55 to attach the pillow to the fuel dock. A longitudinal seam 20 is shown sewn along the center axis of the pillow, and lateral seams 21, 22, 23, 24, 25, 26, and 27 are shown sewn at evenly spaced intervals from one side of the pillow to the opposite side of the pillow and crossing the longitudinal seam along the center axis seam of the pillow in a perpendicular orientation. These seams are shown in greater detail in FIG. 4. Grommets 28 and 29 are placed on the longitudinal seam along the center axis seam of the pillow on each end of the pillow to serve as a connecting point with other pillows to form a continuous boom.
FIG. 2 is an exploded illustration of the first embodiment of the device in FIG. 1, showing alternating layers of textile material 4 and 6 and solidifying polymer 3, 5, and 7 in a stratified arrangement between the layers of textile material 2 and 2x comprising the outer envelope of the device.
Referring to FIG. 5, the cross-section of the first embodiment of the pillow prior to closure at seam 2d reveals the stratification design of the pillow achieved by stacking pieces of textile material 2, 4, 6, and 2x and seaming them at points 2a, 2b and 2c using the overlock seam illustrated in FIG. 3. The cross-section of the boltrope portion of the pillow 55, created by sewing a length of rope into the outer envelope, is shown along seam 2a. The resulting pockets are arranged one on top of another and enclosed by a common outer envelope of layers 2 and 2x. Next, a seam 20 is sewn along the center axis of the pillow, providing a line of additional consolidating points of the internally stratified layers of textile material with the outer envelope of the pillow along its longitudinal axis and creating two columns of pockets 11, 12, and 13 and 14, 15, and 16 within the device. FIG. 5 shows the effect of alternate multi-layering of textile material layers 2, 4, 6 and 2x and the consolidation of the layers along seams 2a, 2b, 2c and 20 to form pockets 11, 12, 13, 14, 15, and 16. These pockets are then filled with polymer and sealed into the body of the pillow, resulting in an arrangement of stratified polymer-filled chambers.
The polymer is inserted into the device by placing a measured amount of the polymer in each pocket at the open end of the device and allowing the polymer to drop through the pockets until it is contained by seam 2b. The polymer is then sealed in the pockets with lateral seam 21, sewn from seam 2a to seam 2c and crossing seam 20 at a perpendicular angle. Seam 21 seals the polymer into chambers and creates an additional line of consolidation points of the layers of textile material. The sealing of the polymer into chambers results in an even distribution of the polymer throughout the device as it prevents loose polymer from migrating throughout the body of the device and clustering in a few areas.
The filling process is repeated, allowing the polymer to drop through the pockets until it is contained by seam 21 with seam 22 sewn to form the next section of stratified polymer-filled chambers. The process is repeated until the last section of pockets is filled with polymer. The last section of polymer-filled chambers and the pillow is seamed shut by seam 2d.
The internally stratified layers of textile material are consolidated with the outer envelope of the pillow at the seams 2a, 2b, 2c and 2d around the perimeter of the pillow, and at seams 20, 21, 22, 23, 24, 25, 26, and 27 along the longitudinal and lateral axes of the device. This allows liquid hydrocarbons that come in contact with the outer envelope layers of textile material 2 and 2x to migrate via the seams 2a, 2b, 2c, 2d, 20, 21, 22, 23, 24, 25, 26, and 27 under capillary attraction to the interior layers of textile material 4 and 6 and propagate throughout the pillow.
In accordance with the first embodiment directed to containment sumps and the like, the pillow envelope 2 measures 48"×6"×1/2". Each pillow chamber contains approximately 8 grams by weight of the solidifying polymer material for an approximate total weight of 1008 grams of polymer in the pillow. The textile material is preferably a petro-chemical based fabric such as polypropylene, polyester or nylon. The polymer material is preferably an organic elastomer polymer sold under the trademarks Waste-Set 3200, Waste-Set 3400, Nochar A610, Nochar A650, Enviro-Bond 403, Norsorex APX1, H-100 Environmental Spill Encapsulant or an equivalent.
FIG. 6 is an exploded illustration of the second embodiment of the device in FIG. 1, showing stratified layers of individual polymer-filled bags 30, 31 and 32 in a stratified arrangement between the layers of textile material 2 and 2x comprising the outer envelope of the device.
Referring to FIG. 7, a series of polymer-filled and sealed bags of single layer textile material are shown joined by ultra-sonic seams. This method of seaming is used to encase the polymer in each of the individual bags, to seal the stratified layers of individual polymer-filled bags within the outer envelope of textile material along the perimeter of the pillow and to create the consolidation seams of the outer envelope of textile material with the substantially registered junctions of the stratified layers of individual polymer-filled bags of the device in FIG. 6;
Referring to FIG. 8, the cross-section of the second embodiment of the device prior to closure at seam 2d reveals the stratification design of the pillow achieved by stratifying layers of individual polymer-filled bags 33, 34, 35, 36, 37 and 38 between outer envelope layers of textile material 2 and 2x. The ultra-sonic seam illustrated in FIG. 7 is used to consolidate the outer edges of the internal layers of polymer-filled bags with the outer edges of the textile material forming the outer envelope of the device along seams 2a, 2b and 2c. The cross-section of the boltrope portion of the pillow 55, created by sewing a length of rope into the outer envelope, is shown along seam 2a. Seam 20 is sewn along the center axis of the pillow and seams 21, 22, 23, 24, 25, 26 and 27 are sewn laterally across the pillow to consolidate the outer envelope layers with the internal layers along the junctions of the substantially registered stratified layers of individual polymer-filled bags.
FIG. 8 shows the effect of the stratified layering of individual polymer-filled bags 33, 34, 35, 36, 37 and 38 between the outer envelope layers of textile material 2 and 2x and the consolidation of the layers along seams 2a, 2b, 2c and 20 22, 23, 24, 25 and 26 to form an arrangement of polymer-filled chambers within the body of the device. The internally stratified layers of individual polymer-filled bags are consolidated with the outer envelope of the pillow at the seams 2a, 2b, 2c and 2d around the perimeter of the pillow, and at seams 20, 21, 22, 23, 24, 25, 26, and 27 along the longitudinal and lateral axes of the device.
These seams allow liquid hydrocarbons that come in contact with the outer envelope layers of textile material 2 and 2x to migrate via the seams 2a, 2b, 2c, 2d, 20, 21, 22, 23, 24, 25, 26, and 27 under capillary attraction to the interior layers of individual polymer-filled bags 33, 34, 35, 36, 37 and 38 and propagate throughout the pillow.
In accordance with the second embodiment directed to containment sumps and the like, the pillow envelope 2 measures 48"×6"×1/2". Each pillow chamber contains approximately 12 grams by weight of the solidifying polymer material for an approximate total weight of 576 grams of polymer in the pillow. The textile material is preferably a petro-chemical based fabric such as polypropylene, polyester or nylon. The polymer material is preferably an organic elastomer polymer sold under the trademarks Waste-Set 3200, Waste-Set 3400, Nochar A610, Nochar A650, Enviro-Bond 403, Norsorex APX1, H-100 Environmental Spill Encapsulant or an equivalent.
FIG. 9 is an exploded illustration of the third embodiment of the device in FIG. 1, showing layers of solidifying polymer suspended in textile material 40, 41 and 42 in a stratified arrangement between the layers of textile material 2 and 2x comprising the outer envelope of the device.
Referring to FIG. 10, the cross-section of the third embodiment of the device prior to closure at seam 2d reveals the stratification design of the pillow achieved by stratifying layers of polymer suspended in textile material 43, 44 and 45 between outer envelope layers of textile material 2 and 2x and seaming them at points 2a, 2b and 2c using the overlock seam illustrated in FIG. 3. The cross-section of the boltrope portion of the pillow 55, created by sewing a length of rope into the outer envelope, is shown along seam 2a. Seam 20 is sewn along the center axis of the pillow, providing a line of additional consolidating points of the internally stratified layers of polymer suspended in textile material with the outer envelope of the pillow along its longitudinal axis and creating two columns of internally stratified layers of polymer suspended in textile material 43, 44 and 45, and 46, 47 and 48 within the device. FIG. 10 shows the effect of the stratified layering of polymer suspended in textile material 43, 44 and 45, and 46, 47 and 48 between the outer envelope layers of textile material 2 and 2x and the consolidation of the layers along seams 2a, 2b, 2c and 20, 21, 22, 23, 24, 25 and 26 to form an arrangement of polymer-filled chambers within the body of the device.
These seams allow liquid hydrocarbons that come in contact with the outer envelope layers 2 and 2x to migrate via the seams 2a, 2b, 2c, 2d, 20, 21, 22, 23, 24, 25, 26, and 27 under capillary attraction to the interior stratified layers of polymer suspended in textile material 43, 44 and 45, and 46, 47 and 48 and propagate throughout the pillow.
In accordance with the third embodiment directed to containment sumps and the like, the pillow envelope 2 measures 48"×6"×1/2". Each layers of polymer suspended in textile material contains approximately 128 grams by weight of the solidifying polymer material for an approximate total weight of 384 grams of polymer in the pillow. The textile material is preferably a petro-chemical based fabric such as polypropylene, polyester or nylon. The polymer material is preferably an organic elastomer polymer sold under the trademarks Waste-Set 3200, Waste-Set 3400, Nochar A610, Nochar A650, Enviro-Bond 403, Norsorex APX1, H-100 Environmental Spill Encapsulant or an equivalent.
FIG. 11 is a cross-section of the extrusion used to hold the pillows in place on the water's surface around the edges of the fuel dock. The channel 56, is of a sufficient diameter to accommodate the boltrope sewn into the outer envelope of the pillows. The opening on the outer side of the channel, running the length of the extrusion between edges 51 and 52, allows the seam between the body of the pillow and the boltrope to pass through the extrusion as it is being slid into place. Vertical tabs 53 and 54 are used to secure the extrusion to the dock and finger piers sections of the fuel slip.
Referring to FIG. 12, a pillow 1 is shown being placed in a length of extrusion 50. The boltrope portion of the pillow 55 is placed inside the channel of the extrusion 56, with seam 2a of the pillow passing through the open slit in the extrusion found between edges 51 and 52. The length of extrusion 50 is attached to the dock at the waterline level by drilling holes in tabs 53 and 54 and placing fasteners through the holes and bolting the extrusion to the dock.
FIG. 13 is a view of a vessel 70 moored in the fuel slip. The vessel is surrounded by an arrangement of pillows 1 held in place on the surface of the water 69 by lengths of extrusion 50 attached to the dock 60. A chain of solidifying pillows 1, is shown in place on the surface of the water 69 across the open end of the fuel slip.
Ambient temperature and the viscosity of the liquid hydrocarbon to be solidified are the two most critical factors in determining the rate of absorption and the amount of time required to solidify the broad spectrum of liquid hydrocarbons this invention is designed to contain for removal and disposal. To enhance the polymer's effective interaction with pollutants, the pillow's construction utilizes the layering of polymer material and textile material to control the rate of absorption and solidification.
The effectiveness of the pillow is further enhanced with the addition of quilting seams. A longitudinal seam 20 along the center axis of the pillow and lateral seams 21, 22, 23, 24, 25, 26 and 27 perpendicular to the center axis of the pillow provide consolidation points of the internally stratified layers of textile material with the external textile material envelope and forms chambers within the pillow. The consolidation of the internal layers of textile material within the outer envelope speeds migration of the liquid hydrocarbons throughout the interior stratified layers of the pillow via the capillary attraction of the liquid hydrocarbons to the textile material. The lateral seams may also be oriented at an oblique angle to the center axis of the pillow. In either case, a quilted effect is achieved. Also, instead of a longitudinal center axis seam, a plurality of parallel longitudinal seams could be used. Further, the quilting effect may be achieved using a plurality of seams criss-crossing at oblique angles to one another so as to form the pockets in a diamond-shape rather than square or rectangular shapes.
The stratification design allows for optimum efficiency in utilizing the solidifying properties of the polymer. Very light viscosity liquid hydrocarbons react almost instantaneously with the polymer and are exposed to no more polymer than can be fully utilized for absorption and solidification. Stratification promotes rapid migration of light viscosity liquid hydrocarbons throughout the interior of the pillow, while slowing migration of the liquid hydrocarbons through the outer surface envelope area and exposure to the polymer. The extremely rapid reaction between the light viscosity liquid hydrocarbon and the polymer could otherwise result in the loose polymer located within the volume of the pillow being surrounded by a non-permeable, rubber-shell. The resulting surface blockage would thereby prevent the enclosed polymer from being used to solidify additional liquid hydrocarbons.
In addition, the stratification design allows the heavier viscosity liquid hydrocarbons that migrate through the layers of textile material to be suspended inside the pillow awaiting the polymer to absorb them and begin the solidification process.
The properties of the textile material that allow for rapid absorption and migration of all viscosities of liquid hydrocarbons effectively give the device maximum surface area exposure of the polymer through the stratification design.
Additional applications include, but are not limited to, removal of liquid hydrocarbons from bilges of marine vessels, monitor wells, electric utility transformers, petrochemical plants and pipelines, aviation fueling facilities and rail and trucking fueling terminals as well as use as a containment and clean-up product for municipal entities charged with eliminating petrochemical spills.
The foregoing description of the preferred embodiment has been for the purpose of explanation and illustration. It will be appreciated by those skilled in the art that many modifications and changes can be made in the structure without departing from the essence of the present invention. Therefore, it is contemplated that the appended claims will cover any modifications or embodiments which fall within the scope of the invention.
|
A system to contain, collect and remove hydrocarbons such as gasoline, diesel and/or lubricants that are spilled or leaked on to the surface of the water during fueling operations at marine fueling facilities. The system utilizes a series of absorbent devices formed as pillows and held in place on the surface of the water along the dock area of a fueling facility that absorb hydrocarbon pollutants that they come in contact with. The absorbed hydrocarbons are solidified within the pillow into a rubber-like mass. The consolidated mass is contained within the pillows, will float indefinitely and is easily retrieved and handled for disposal. Once the capacity of a pillow is reached, it will continue to act as a containment boom to keep the spill on the water's surface from spreading throughout the fueling facility area, allowing the spill to reach another pillow with the capacity to absorb and solidify the spill. A pillow that has reached its full absorbing and solidifying capacity can be easily replaced with a fresh pillow using a simple system of attaching the pillows to the periphery of the fueling facility. The solidified hydrocarbons will not leech when exposed to pressure limits used to determine landfill suitability. The solidified devices can be disposed of as landfill, incinerated as a fuel or utilized as a component in the production of asphalt, roofing materials or other tar-like compounds.
| 4
|
FIELD OF INVENTION
[0001] The present invention relates to novel loganin analogues and a process for the preparation thereof. More particularly the present invention relates to use of Iridoid glycoside loganin isolated from the fruit pulp of Strychnos nux - vomica and its bioactive semi-synthetic analogues against various human cancer cell lines grown in-vitro.
BACKGROUND OF INVENTION
[0002] Cancer is one of the most dreaded diseases of the 20th century and spreading further with continuance and increasing incidence in 21st century. In the United States, as the leading cause of death, it accounts for 25% of all the deaths in humans presently. It is considered as an adversary of modernization and advanced pattern of socio-cultural life dominated by Western medicine. Multidisciplinary scientific investigations are making best efforts to combat this disease, but the sure-shot, perfect cure is yet to be brought into world of medicine.
[0003] Natural anticancer agents are an important area of the current research and are in good demand all over the world. As a result of endless efforts by the scientist around the world, certain lead molecule such as vincristine (VCR), vinblastine (VLB), taxol and camptothecin have been discovered as nature's boon for cancer therapy.
[0004] Iridoid glycosides are important natural product and occur in a large number of plant families. Many reviews have dealt with their distribution, structure, properties and biosynthesis (Balachandran, P. Govindarajan, R. Pharmacological Research. 2005, 51, 19; El-Naggar, L. J. Beal, J. L. J. Nat. Prod. 1980, 43, 649). They have been reported to possess various biological activities such as antitumoral (Ishiguru, K.; Yamaki, M.; Takayi, S.; Ikada, Y.; Kawakani, K.; Ito, K.; Nose, T. Chem. Pharm. Bull. 1986, 34, 23) hemodynamic (Circosta, C.; Occhiuto, F.; Ragusa, S.; Trovato, A.; Tumino, G.; Briguglio, F.; De Pasquale, A.; J. Ethnopharmacol. 1984, 11, 259.), cholaratic (Miyagoshi, M.; Amagaya, S.; Ogihara, Y.; J. Pharmabiodyn. 1988, 11, 186), hepatoprotective (Chang, I. M.; Ryu, J. C.; Park, I. C.; Yun, H. S.; Yang, K. H. Drug Chem. Toxicol. 1983, 6, 443), antimicrobial, hypotensive, analgetic, antichloristic, sedative, laxative and various other effects (Sticher, O. (1977) In; New Natural Products and Plant Drugs with Pharmacological, Biological or Therapeutical Activity, (Wagner, H.; Wolff, P.; eds.). 137-176, Springer Verlag, Berlin).
[0005] Loganin, an iridoid glycoside is the major constituent of Strychnos nux - vomica fruit pulp. It has long been used as a precursor for the biosynthesis of indole alkaloids and lately it has been reported to posses various pharmacological activities (Graiku, K.; Aligiannis, N.; Chinou, I. B.; Harvala, C. Z. Naturforsch. 2002, 57C, 95; Mathad, V. T.; Raj, K.; Bhaduri, A. P.; Sahai, R.; Puri, A.; Tripathi, L. M.; Srivastava, V. M. L.; Bioorganic & Meidcinal Chemistry, 1998, 6, 605; Visen P. K. S.; Saraswat, B.; Raj, K.; Bhaduri, A. P.; Dubay, M. P.; Phytotherapy Research, 1998, 12, 405; Raj, K.; Matahad , V. T.; Bhaduri, A. P.; Ind. J. Chem., 1996, 35B, 1056; Recio, M. C.; Griner, R. M.; Manez, S.; Rias, J. L. Planta Med., 1994, 60, 232; Tandon, J. S.; Srivastava, V.; Guru, P. Y. J. Nat. Prod. 1991, 54, 1102; Handa S. S.; Sharma, A.; Chakroborti, K. K. Fitoterapia, 1986, 27, 307; Woerdengbag H. J.; Moska T. A.; Pras, N,; Malingre T. M. J. Nat. Prod. 1993, 56, 849. Strychnos Linn. (Fam. Loganiaceae) a large genus of scandent shrub or trees, found throughout the tropic and subtropics. Nearly 20 species occur in India, of which Strchnos nux - vomica renowned for the drug value of its poisonous alkaloids, Strychnine and Brucine. Strchnos nux - vomica is commonly known as Snake-wood or nux - vomica tree ( Anonymous, wealth of India, vol X. CSIR, New Delhi, 1961, 62).
[0006] Chemical investigations:
[0007] On going through the literature it was observed that loganin, a bitter glycoside isolated from Strchnos nux - vomica (Dunstan, W. R.; Short, F. W.; Pharm J Trans, 1983, 14, 1025; Merz, K. W.; Kerbs, K. G.; Arch Pharm, 1937, 275, 217; Meez, K. W.; Lehmann, H.; Arch Pharm, 1957, 290, 543) and other species of strychnos, Menyanthes trifoliate, Lonicera and Hydrangea -species has recently been the subject of various chemical and biosynthetic investigations. In 1974 Bisset et al isolated loganin from the fruit pulp of Strchnos nux-vomica as a major iridoid along with other minor iridoids and alkaloids. In the same year Isiguro et al reported the antitumor activity of several iridoid glycosides and their aglycones. In 1986 Handa et al reported that in traditional system of medicine, an iridoid glycoside (loganin) have a promising protective effect against liver disorders.
[0008] In 1991 Tandon et al J. Nat. Prod. 1991, 54, 1102, reported the antileishmanial activity of iridoid glycosides both in vitro (against anastigoles in macrophage cultures) and in vivo (in hamsters) test system. In 1994 Ricio et a.l Planta Med., 1994, 60, 232 studied the structrural considerations on the iridoids as anti-infllammatory agents. In 1996 Raj et al. Ind. J Chem., 1996, 35B, 1056, described synthesis of various loganin analogues and their hepatoprotective evaluation with structural activity relationship. In 1998 Mathad et al. Bioorganic & Meidcinal Chemistry, 1998, 6, 605 studied the immunostimulant activity profile of modified iridoid glycosides prepared from loganin, keto-loganin and arbortristoside A and some structure activity relationship was carried out.
[0009] The detailed literature search revealed that loganin is present in fruit pulp of Strchnos nux - vomica in sufficient amount (Bisset, N. G.; Choudhury, A. K. Phytochemistry, 1974, 13) and possesses various important biological activities such as hepatoprotective (Raj, K.; Matahad , V. T.; Bhaduri, A. P.; Ind. J. Chem., 1996, 35B, 1056), immunostimulant, antimicrobial and various other effects (Sticher, O. (1977) In; New Natural Products and Plant Drugs with Pharmacological, Biological or Therapeutical Activity, (Wagner, H.; Wolff, P.; eds.). 137-176, Springer Verlag, Berlin).
[0010] It was also recorded that few short report appeared in literature, refrerence may be made to Bisset, N. G.; Choudhury, A. K. Phytochemistry, 1974; Mathad, V. T.; Raj, K.; Bhaduri, A. P.; Sahai, R.; Puri, A.; Tripathi, L. M.; Srivastava, V. M. L.; Bioorganic & Meidcinal Chemistry, 1998, 6, 605 and Raj, K.; Matahad , V. T.; Bhaduri, A. P.; Ind. J. Chem., 1996, 35B,1056, on loganin for their various biological activities but to the best of our knowledge no work on the anticancer activity of loganin and its semi-synthetic analogues have been reported so far. Hence we wish to report the anticancer activities of loganin and its new semi-synthetic analogues against various human cancer cell lines grown in-vitro. Isolation of loganin was cariied out from the fruit pulp of Strychnos nux - vomica. Further chemical transformation of loganin was carried out to prepare various new synthetic analogues. Finally loganin and its various new synthetic analogues were evaluated for their anticancer activity against various human cancer cell lines.
SUMMARY OF THE INVENTION
[0011] Accordingly the present invention provides novel loganin analogues of formula I
[0012] In an embodiment of the present invention the novel loganin analogues of formula1, are represented by the group of the following compounds:
[0013] 2′,3′,4′,7-Tetra-O-acetylloganin (4), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-propionylloganin (5), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-lauroylloganin (6), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-myristoylloganin (7), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-palmitoyl loganin (8), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-acryloyl loganin (9), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3″,3″-dimethyl acryloylloganin (10), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin (11), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-(3′″)-nitrobenzoyl loganin (12).
[0014] The present invention further provides a process for the preparation of loganin analogue of formula 1,
the said process comprising the steps of: a) dissolving loganin (1) in pyridine and reacting it with trityl chloride, under stirring, at a temperature in the range of 30-40° C., adding crushing ice to the above said reaction mixture and extracting the resultant mixture with chloroform and further extracting the resultant extract with about 6% HCl, followed by washing with water and drying by known method to obtain 6′-O-trityl loganin (2), b) acetylating the above said compound (2) in pyridine with acetic anhydride to obtain the compound 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3), c) hydrolyzing the above said compound obtained (3) in step (b) by dissolving it in 70-90% acetic acid solution and refluxing it, at 70-90° C., for about 1 hr, adding water to above said reaction mixture, followed by extraction with chloroform, washing the resultant extract with water till it's neutralization, and drying by known method to obtain the compound 2′,3′,4′,7-tetra-O-acetyl loganin (4), d) acetylating or arylating the above said compound 2′,3′,4′,7-tetra-O-acetyl loganin (4) obtained in step (c) by dissolving it either chloroform along with catalytic amount of 4-dimethyl amino pyridine (DMAP) or in pyridine and reacting it with desired acid chloride or acid anhydride, for an over night period, at a temperature of 30-45° C., adding ice to the above said reaction mixture and extracting the resultant mixture with chloroform, followed by washing with water till it's neutralization, followed by purification and drying by known method to obtain the desired product from compounds (5) to (12).
[0020] In yet another embodiment the trityl chloride used in step (a) is in the range of 1-1.5 equivalent to loganin (1).
[0021] In yet another embodiment the compounds (5) to (12) obtained are represented by a group of the following compounds:
[0022] 6′-O-trityl loganin (2), 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3), 2′,3′,4′,7-tetra-O-acetyl loganin (4), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-propionylloganin (5), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-lauroylloganin (6), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-myristoyl loganin (7), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-palmitoyl loganin (8), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-acryloyl loganin (9), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3″,3−-dimethyl acryloylloganin (10), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin (11), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-(3′″)-nitrobenzoyl loganin (12).
[0023] The present invention further provides a pharmaceutical composition comprising loganin (1) or its analogues, salts or mixture thereof, optionally with pharmaceutically acceptable carrier, adjuvant and additives.
[0024] A composition as claimed in claim 6 , wherein the loganin analogues used are represented by a group of the following compounds:
[0025] 6′-O-trityl loganin (2), 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3), 2′,3′,4′,7-tetra-O-acetyl loganin (4), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-propionylloganin (5), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-lauroylloganin (6), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-myristoyl loganin (7), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-palmitoyl loganin (8), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-acryloyl loganin (9), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3″,3″-dimethyl acryloylloganin (10), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin (11), 2′,3′,4′,7-Tetra-O-acetyl-6′-O-(3′″)-nitrobenzoyl loganin (12).
[0026] In yet another embodiment the loganin used is isolated from the fruits pulp of Strychnos nux - vomica.
[0027] In yet another embodiment the loganin and its analogues exhibits anticancer activity against human cancer cell.
[0028] In yet another embodiment the composition exhibits anti cancer activity against but not limited to breast (MCF-7), Ovary (PA-1), Liver (WRL), Colon (COLO-320, CaCo2) cancer cells.
[0029] In yet another embodiment the pharmaceutical composition is useful as cancer chemotherapy agent.
[0030] In yet another embodiment the concentration of loganin (1) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 1 to 5 μg/ml.
[0031] In yet another embodiment the concentration of 6′-O-trityl loganin (2) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.25 to 2.0 μg/ml.
[0032] In yet another embodiment the concentration of 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.80 to 3.50 μg/ml.
[0033] In yet another embodiment the concentration of 4′,7-Tetra-O-acetyl-6′-O-propionylloganin (5) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.80-3.0 μg/m.
[0034] In yet another embodiment the concentration of 2′,3′,2′,3′,4′,7-Tetra-O-acetyl-6′-O-lauroylloganin (6) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.04 to 0.85 μg/ml.
[0035] In yet another embodiment the concentration of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-myristoyl loganin (7) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer and COLO-320 of colon cancer is in the range of 6.5 to 59.0 μg/ml.
[0036] In yet another embodiment the concentration of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3″,3″-dimethyl acryloylloganin (10) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.08 to 1.20 μg/ml.
[0037] In yet another embodiment the concentration of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin (11) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.04 to 0.54 μg/ml.
[0038] In yet another embodiment the concentration of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-(3′″)-nitrobenzoyl loganin (12) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.44 to 3.20 μg/ml.
[0039] The present further provides the use of loganin (1) and it's analogues as anticancer activity against human cancer cell lines.
[0040] In yet another embodiment the said compounds are active against but not limited to breast (MCF-7), Ovary (PA-1), Liver (WRL), Colon (COLO-320, CaCo2) cancer cells.
[0041] In yet another embodiment the dose of loganin (1) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 1 to 5 μg/ml.
[0042] In yet another embodiment the dose of 6′-O-trityl loganin (2) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.25 to 2.0 μg/ml.
[0043] In yet another embodiment the dose of 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.80 to 3.50 μg/ml.
[0044] In yet another embodiment the dose of 4′,7-Tetra-O-acetyl-6′-O-propionylloganin (5) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.80-3.0 μg/m.
[0045] In yet another embodiment the dose of 2′,3′,2′,3′,4′,7-Tetra-O-acetyl-6′-O-lauroylloganin (6) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.04 to 0.85 μg/ml.
[0046] In yet another embodiment the dose of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-myristoyl loganin (7) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer and COLO-320 of colon cancer is in the range of 6.5 to 59.0 μg/ml.
[0047] In yet another embodiment the dose of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3″,3″-dimethyl acryloylloganin (10) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.08 to 1.20 μg/ml.
[0048] In yet another embodiment the dose of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin (11) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.04 to 0.54 μg/ml.
[0049] In still another embodiment the dose of 2′,3′,4′,7-Tetra-O-acetyl-6′-O-(3′″)-nitrobenzoyl loganin (12) used in vitro MTT assay for IC 50 in cancer cell line MCF-7 of breast cancer, PA-1 of ovary cancer, WRL of liver cancer, COLO-320 of colon cancer and CaCo-2 of Adherent colon cancer is in the range of 0.44 to 3.20 μg/ml.
DETAILED DESCRIPTION OF INVENTION
[0050] As part of our studies we first isolated loganin from the fruits pulp of S. nux - vomica, and then various new synthetic analogues were prepared. Finally all the analogs along with loganin were tested for their anticancer properties against the five human cancer cell lines in-vitro. The anticancer activity testing was done by MTT assay and finally the results were confirmed by clonogenic assay from which the inhibitory concentration IC 50 the concentration (ug/ml) of the biomolecules required for 50% inhibition of cell growth was deduced. The data obtained in these bioassays against human cancer cells indicated that the parent molecule loganin showed significant cytotoxic activity against all the tested human cancer cell lines. The new analogous 2′,3′,4′,7-tetra-O-acetyl-6′-O-3,4,5-trimethoxy benzoyl loganin and 2′,3′,4′,7-tetra-O-acetyl-6′-O-lauroyl loganin showed 8-13 times higher activity than the known anticancer drug, vinblastine against the human suspension colon (Colo-320) and human adherent colon (CaCo2) cancer cell lines. While the remaining analogues along with the parent molecule, loganin showed compatible activity with vinblastine against the five tested human cancer cell lines.
[0051] The following examples are given by the awy of illustration and therefore should not be construed to limit the scope of the invention.
EXAMPLE-1
[0000] Collection of Plant Material and Extraction
[0052] The Strchnos nux - vomica fruits were collected locally from Lucknow, in the month of December 2000. The pulp of Strchnos nux - vomica fruits was obtained by removing seeds and peel from the fruits (˜12 Kg), this was successively extracted thrice at room temperature over night with MeOH in a percolator. The combined MeOH extract was concentrated under vacuum on a Buchi rotar vapour and finally dried on a high vacuum pump until the MeOH was completely removed.
[0053] The dried methanolic extract was dissolved in distilled water and filtered. The aqueous extract (filtrate) so obtained was fractionated successfully with n-hexane, ethyl acetate and n-butanol saturated with water to yield corresponding extracts.
EXAMPLE-2
[0000] Isolation of Loganin from Fruit Pulp of Strchnos nux - vomica
[0054] All the above fractions (n-hexane, ethyl acetate and n-butanol) were monitored on TLC, which showed that loganin was present in n-BuOH extract. The concentrated n-BuOH extract was kept in refrigerator for overnight, which afforded a white precipitate. The TLC profile of the precipitate showed that it is mainly loganin associated with some minor non polar impurities. Further purification of loganin was carried out as given below in the flow chart.
EXAMPLE-3
[0000] Preparation of Various Synthetic Analogues of Loganin
[0000] Tritylation of Loganin
[0055] The loganin was dissolved in pyridine and trityl chloride was added in 1.5 equivalents and stirred at 45° C. for 36 hrs to give the compound 6′-O-trityl loganin (2) in 65% yield.
[0000] Work up of the Reaction
[0056] After completion of the reaction, crushed ice was added to the reaction mixture and the mixture was then extracted with chloroform (4 times). The CHCl 3 extract was then extracted with 6% HCl solution (4 times). The chloroform solution was then washed with H 2 O (until it was neutralized), dried over anhydrous Na 2 SO 4 and solvent removed under vacuum at 40° C. The TLC profile of CHCl 3 extract showed tritylated product as the major component along with several other minor products, which was further purified by column chromatography.
[0000] Column Chromatographic Separation of the Tritylated Product
[0057] Column chromatographic separation of the tritylated product resulted in isolation of compound, 6′-O-trityl loganin (2) in 65% yield eluted with solvents CHCl 3 :MeOH (97:3).
[0000] Acetylation of Compound 2
[0058] Compound 2 was acylated in pyridine with acetic anhydride to give 2′,3′,4′,7-tetra-O-acetyl-6′-O-trityl loganin (3) in 92.1% yield.
[0000] Hydrolysis of Compound 3
[0059] Compound 3 was dissolved in 80% acetic acid solution and reflux at 80° C. for 1 h. Completion of the reaction was checked by TLC. After completion of the reaction, water was added and extracted four times with chloroform. The pooled chloroform extract was washed with water (until it was neutralized). The neutralized chloroform extract was dried over anhydrous Na 2 SO 4 and solvent removed under vacuum.
[0000] Column Chromatographic Separation of the Hydrolyzed Product
[0060] Column chromatographic separation of the hydrolyzed product resulted in the isolation of purified compound, 2′,3′,4′,7-tetra-O-acetyl loganin (4) in 76.7% yield eluted with the solvent system CHCl 3 : MeOH (99:1).
[0000] Preparation of New Acyl/Aryl Analogues of Compound 4
[0061] Further partially protected compound 4 was acylated/arylated with different acid chlorides/acid anhydrides by using the following methods.
[0000] General Procedure
[0000] Method 1:
[0062] The partially protected compound, 4 was dissolved in CHCl 3 along with catalytic amount of 4-dimethyl amino pyridine (DMAP) and then different acid chlorides/acid anhydrides were added in 1:1.5 ratio. The reaction mixtures were kept overnight at room temperature (30-45° C.). The progress of the reactions was checked by TLC. After completion of the reaction, ice water was added (˜15 ml) and reaction solutions were extracted three times with chloroform. The combined chloroform extracts was washed with water (until it was neutralized). The neutralized chloroform extract was dried over Na 2 SO 4 and concentrated on a rotatory evaporator under reduced pressure.
[0000] Method 2:
[0063] The partially protected compound, 4 was dissolved in pyridine and then different acid chlorides/acid anhydrides were added in 1:1.5 ratio. The reaction mixtures were kept overnight at room temperature (30-45° C.). The progress of the reaction was checked by TLC. After completion of the reaction, ice cold water was added and the reaction mixture was extracted four times with chloroform. The chloroform extracts were pooled together and washed four times with 6% HCl solution. The chloroform solution so obtained was washed with water until it was neutralized. The neutral chloroform extract was dried over anhydrous Na 2 SO 4 and solvent removed under vacuum at 40° C.
[0000] Preparation of Propionyl Derivative of Compound 4 with Propionic Anhydride
[0064] The partially protected compound, 4 (200 mg) was dissolved in CHCl 3 along with catalytic amount of 4-dimethyl amino pyridine (DMAP) and then propionic anhydride (0.08ml) was added in 1:1.5 ratio. The reaction mixtures were kept overnight at room temperature (32° C.). The progress of the reaction was checked by TLC. After completion of the reaction, ice water was added (˜15 ml) and reaction solutions were extracted three times with chloroform. The combined chloroform extracts was washed with water (until it was neutralized). The neutralized chloroform extract was dried over Na 2 SO 4 and concentrated on a rotatory evaporator under reduced pressure.
[0000] Column Chromatographic Separation of Various Acyl/Aryl Derivatives of Compound 4
[0065] After work up of the reactions, chloroform extracts of the above acyl/aryl analogues of compound 4 were purified by column chromatographic separation over silica gel using the solvents, hexane and chloroform as eluants in various proportions, which resulted in the isolation of purified products (5-12).
EXAMPLE-4
[0000] Identification of Loganin and its Synthetic Analogues
[0066] Loganin (1) and its synthetic analogues (5-12) were identified on the basis of their 1 H and 13 C NMR spectroscopic data. 1 H and 13 C NMR spectroscopic data of some selected compounds are given below:
[0067] Compound 2: Yield: 65%, m.p.=120° C., 1 HNMR (CDCl 3 ): δ 1.10 (3H, d, J=6.4 Hz, H-10), 1.50 (1H, m, H-6a), 1.90 (1H, m, H-8), 2.10 (1H, m, H-9), 2.30 (1H, m, H-6b), 2.50 (1H, m, H-5), 3.20 (1H, t, J=8.0 Hz, H-2′), 3.30- 3.40 (3H, m, H-3′, H-4′ and H-5′), 3.60 (4H, brs, H-12 and H-6′b), 3.80 (1H, brs, H-6′a), 4.00 (1H, brs, H-7), 4.60 (1H, d, J=7.4 Hz, H-1′), 5.10 (1H, d, J=4.6 Hz, H-1), 7.20-7.40 (16H, s, H-3 & Ar—H of 3 phenyl ring), 13 CNMR (CDCl 3 ) C-1 97.60d, C-3 150.50d, C-4 113.40s, C-5 31.60d, C-6 42.40t, C-7 73.80d, C-8 41.30d, C-9 45.80d, C-10 12.90q, C-11 166.00s, C-12 51.00q, C-1′ 99.40d, C-2′ 74.40d, C-3′ 77.00d, C-4′ 71.70d, C-5′ 75.40d, C-6′ 64.10t, C-1″ 87.00s, C-1′″, 1 iv & 1 v 144.10s, C-2′″ & 6″, 2 iv & 6 iv and 2 v & 6 v 128.90d, C-3′″ & 5′″, 3 iv & 5 iv and 3 v & 5 v 127.90d, C-4′″, 4 iv and 4 v 126.80d, FABMS: m/z 632 [M + ]; 4: Yield 76.7%, m.p.=148-150° C., 1 HNMR (CDCl 3 ): 1.00 (3H, d, J=6.5 Hz, H-10), 1.75-1.82 (2H, m, H-6a and H-8), 1.90-2.10 (12H, s, 3H each, 4×OCOCH 3 ), 2.20-2.30 (2H, m, H-9 and H-6b), 3.00 (1H, m, H-5), 3.50 (1H, brs, H-6′b), 3.60 (1H, m, H-6′a), 3.70 (4H, s, H-5′ and H-12), 4.80 (1H, d, J=7.9Hz, H-1′), 4.90 (1H, m, H-2′), 5.00 (1H, m, H-7), 5.10 (1H, m, H-1), 5.20 (2H, brs, H-3′ and H-4′), 7.3 (1 H, s, H-3), 13 CNMR (CDCl 3 ) C-1 95.80d, C-3 150.00d, C-4 114.00s, C-5 30.90d, C-6 39.50t, C-7 77.40d, C-8 39.50d, C-9 46.90d, C-10 12.90q, C-11 167.50s, C-12 51.30q, C-1′ 96.90d, C-2′ 71.60d, C-3′ 75.20d, C-4′ 70.00d, C-5′ 76.30d, C-6′ 63.40t, C-7- C OCH 3 (169.40s), C-7-CO CH 3 (20.40q), C-2′- C OCH 3 (171.40s), C-2′-CO CH 3 (21.10q), C-3′- C OCH 3 (170.60s), C-3′-CO CH 3 (20.9q), C4′- C OCH 3 (171.2s), C-4′-CO CH 3 (21.9q), FABMS: m/z 558 [M + ] 5: Yield 98.4%, m.p.=92° C., 1 HNMR (CDCl 3 ): 1.00 (3H, d, J=6.7 Hz, H-10), 1.11 (3H, t, J=7.5 Hz, H-2′″), 1.84-1.90 (2H, m, H-6a and H-8), 1.94, 2.00, 2.04, 2.10 (3H each, s, 4×OCOCH 3 ), 2.22 (2H, m, H-9 and H-6b), 2.31 (2H, m, H-1′″), 3.00 (1H, m, H-5), 3.69 (3H, s, H-12), 3.70 (1H, m, H-5′b), 4.16 (1H, m, H-6′b), 4.28 (1H, m, H-6′a), 4.90 (1H, d, J=8.1 Hz, H-1′), 5.00 (1H, t, J=9.4 Hz, H-2′), 5.10 (2H, m, H-7′ and H-1′), 5.20 (2H, m, H-3′ and H-4′), 7.30 (1H, s, H-3). 13 CNMR (CDCl 3 ): C-1 95.20d, C-3 149.30d, C-4 113.70s, C-5 30.30d, C-6 39.10t, C-7 77.00d, C-8 39.10d, C-9 46.00d, C-10 12.50q, C-11 168.90s, C-12 51.00q, C-1′ 96.30d, C-2′ 71.10d, C-3′ 72.60d, C-4′ 68.60d, C-5′ 72.80d, C-6′ 62.10t, C-7- C OCH 3 (169.80s), C-7-CO CH 3 (20.10q), C-2′- C OCH 3 (173.0s), C-2′-CO CH 3 (20.80q), C-3′- C OCH 3 (170.10s), C-3′-CO CH 3 (20.4q), C-4′- C OCH 3 (171.9s), C-4′-CO CH 3 (20.5q), FABMS: m/z 614 [M + ], Elemental analysis for C 28 H 38 O 15 Calc; C, 54.7, H, 6.2; Observ., C, 54.0, H, 6.0, 6: Yield: 98.6, m.p.=Oil, 1 H NMR (CDCl 3 ): 0.87 (3H, brs, H-11′″), 1.00 (3H, brs, H-10)1.25 (16H, brs, H-3′″-H-10′″), 1.50 (2H, m, H-2′″), 1.75-1.90 (2H, m, H-6a and H-8), 1.99 -2.06 (12H, s, 4×OCOCH 3 ), 2.09 (2H, m, H-9 and H-6b), 2.20 (2H, m, H-1′″), 3.00 (1H, m, H-5), 3.70 (4H, brs, H-5′ and H-12), 4.16 (1H, m, H-6′b), 4.24 (1H, m, H-6′a), 4.80 (1H, brs, H-1′), 4.90 (1H, d, J=7.9 Hz, H-2′), 5.10 (2H, m, H-7 and H-1), 5.20 (2H, brs, H-3′ and H-4′), 7.30 (1H, s, H-3), 13 CNMR (CDCl 3 ): C-1 95.00d, C-3 148.90d, C-4 113.40s, C-5 30.50d, C-6 38.70t, C-7 76.60d, C-8 38.70d, C-9 45.80d, C-10 12.10q, C-11 166.80s, C-12 50.50q, C-1′ 96.00d, C-2′ 71.00d, C-3′ 72.30d, C-4′ 68.70d, C-5′ 72.50d, C-6′ 61.80t, C-1″ 172.80s, C-1′″ 33.70t, C-2′″ 31.50t, C-3′″-C-8′″ 29.8-29.3t, C-9′″ 24.40d, C-10′″ 22.20t, C-11′″ 13.40q, C-7- C OCH 3 (168.9s), C-7-CO CH 3 (19.6q), C-2′- C OCH 3 (170.9s), C-2′-CO CH 3 (20.7q), C-3′- C OCH 3 (169.5s), C-3′-CO CH 3 (20.3q), C-4′- C OCH 3 (170.1s), C-4′-CO CH 3 (20.4q), FABMS: m/z 740 [M + ] Elemental analysis C 37 H 56 O 15 Calc; C, 60.0, H, 7.6; Observ; C, 59.2, H, 7.4; 9: Yield: 81.0%, m.p=68-70° C., 1 H NMR (CDCl 3 ): 0.99 (3H, d, J=3.5 Hz, H-10), 1.74-1.87 (2H, m, H-6a and H-8), 1.90-2.00 (12H, s, 3H each, 4×OCOCH 3 ), 2.06-2.20 (2H, m, H-9 and H-6b), 3.00 (1H, m, H-5), 3.60 (3H, s, H-12), 3.70 (1H, m, H-5′), 4.09 (1H, m, H-6′b), 4.17 (1H, m, H-6′a), 4.82 (1H, m, H-1′), 4.97 (1H, d J=5.9 Hz, H-2′), 5.10 (2H, m, H-7 and H-1), 5.20 (2H, m, H-3′ and H-4′), 5.25 (1H, d, J=9.5 Hz, H-2′″a), 5.70 (1H, m, H-1′″), 6.94 (1H, m, H-2′″b), 7.30 (1H, s, H-3), 13 CNMR (CDCl 3 ): C-1 95.70d, C-3 149.40d, C-4 113.80s, C-5 30.60d, C-6 39.20t, C-7 77.00d, C-8 39.20d, C-9 46.40d, C-10 12.50q, C-11 164.00s, C-12 50.90q, C-1′ 96.60d, C-2′ 71.60d, C-3′ 72.80d, C-4′ 69.20d, C-5′ 72.90d, C-6′ 62.60t, C-1″ 170.00s, C-1′″ 121.90d, C-2′″ 147.00t, C-7- C OCH 3 (165.5s), C-7-CO CH 3 (20.0q), C-2′- C OCH 3 (169.4s), C-2′-CO CH 3 (20.6q), C-3′- C OCH 3 (168.4s), C-3′-CO CH 3 (20.2q), C-4′- C OCH 3 (168.50s), C-4′-CO CH 3 (20.3q), FABMS: m/z 626 [M + ], Elemental analysis for C 29 H 38 O 15 Calc. C, 55.59, H, 6.1; Observ; C, 55.2, H, 6.0; 12: Yield 81%, m.p. 148° C., 1 H NMR (CDCl 3 ): 1.00 (3H, d, J=6.2 Hz, H-10), 1.69-1.87 (2H, m, H-6b and H-8), 1.92-2.06 (12H, s, 3H each, 4×OCOCH 3 ), 2.25 (2H, m, H-9 and H-6a), 3.00 (1H, m, H-5), 3.70 (3H, s, H-12), 3.90 (1H, m, H-5′), 4.30 (1H, m, H-6′b), 4.35 (1H, m, H-6′a), 4.90 (1H, d, J=7.6 Hz, H-1′), 5.10 (1H, t, J=9.0 Hz, H-2′), 5.20 (1H, brs, H-7), 5.30 (2H, m, H-1′ and H-3′), 5.40 (1H, t, J=9.9 Hz, H-4′), 7.30 (1H, s, H-3), 7.70 (1H, t, J=7.2 Hz, H-5′″), 8.30 (1H, d, J=6.7 Hz, H-6′″), 8.40 (1H, d, J=8.0 Hz, H-4′″), 8.80 (1H, s, H-2′″), 13 CNMR (CDCl 3 ): C-1 95.50d, C-3 149.30d, C-4 113.90s, C-5 30.50d, C-6 39.20t, C-7 77.00d, C-8 39.20d, C-9 46.30d, C-10 12.50q, C-11 163.40s, C-12 51.00q, C-1′ 96.50d, C-2′ 71.20d, C-3′ 72.30d, C-4′ 70.80d, C-5′ 72.80d, C-6′ 62.40t, C-1″, 170.30s, C-1′″ 131.10s, C-2′″124.80d, C-3′″149.00s, C-4′″ 127.90d, C-5′″ 129.80d, C-6′″ 135.10d, C-7- C OCH 3 (167.0s), C-7-CO CH 3 (20.0q), C-2′- C OCH 3 (167.0s), C-2′-CO CH 3 (20.0q), C-3′- C OCH 3 (168.9s), C-3′-CO CH 3 (20.3q), C-4′- C OCH 3 (169.8s), C-4′-CO CH 3 (20.4q), FABMS: m/z 707 [M + ], Elemental analysis for C 32 H 37 NO 17 Calc. C, 54.3, H, 5.2; Observ; C, 53.9, H, 5.1.
EXAMPLE-5
[0000] Cytotoxicity Testing of Loganin (1) and its Analogues 2-12
[0068] Cytotoxicity testing In-vitro was done by the method of Woerdenberg et al 17 . 2×10 3 cells/well were incubated in the 5% CO 2 , 95% atmosphere and 37° C. in CO 2 incubator for 24 h to enable them to adhere properly to the 96 well polysterene microplate (Grenier, Germany). Test compounds dissolved in 100% DMSO (Merck, Germany) in at least five doses were added and left for four hour after which the compound plus media was replaced with fresh media and the cell were incubated for another 48 h in the CO 2 incubator at 37° C. The concentration of DMSO used in our experiment never exceeded 1 %, which was found to be non toxic to cells. Then, 10 μL from 5 mg/ml stock of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; Sigma M 2128] was added, and plate were incubated at 37° C. for 4 h. 100 μL of dimethylsulfoxide (DMSO, Merck, Germany) were added to all wells and mixed thoroughly to dissolve the dark blue crystal. After a few minute at room temperature to ensure that all crystal were dissolve, the plate were read on a Spectra Max 190 Microplate Elisa Reader (Molecular Devices Inc., U.S.A), at 570 nm. Plate were normally read within 1 h of adding the DMSO. The experiment was done in triplicate and the inhibitory concentration (IC) values were calculated as; % INHIBITION=[1−OD (570 nm) of sample well/OD (570 nm) of control well]×100. IC 50 is the concentration μg/mL required for 50% inhibition of cell growth as compared to that of untreated control.
EXAMPLE-6
[0000] Cytotoxic Activity of Loganin 1 and its Analogues 2-12
[0069] Loganin and its synthetic anlogues were evaluated in-vitro for their anticancer activity against human breast (MCF-7), Ovary (PA-1), Liver (WRL), Suspension Colon (COLO-320) and Adherent colon (CaCo2) cancer cell lines by MTT assay and results are given in Table-1. From the Tables 1 it is evident that the parent molecule loganin showed significant cytotoxic activity against all the tested human cancer cell lines. On comparing the cytotoxicity of loganin with its synthetic analogues, it is clear that protection of primary alcoholic group of sugar residue with trityl chloride and acetylation of secondary alcoholic group in aglycon and sugar residue of loganin resulted into analogues 2 and 3 having enhanced cytotoxic activity than the starting material loganin against all the tested human cancer cell lines. On the other hand deprotection of primary alcoholic group of sugar residue results the compound with abolished cytotoxicity but it is interesting to note that when the partially protected compound 4 is acylated/arylated with different acid chlorides/acid anhydrides, drastic enhancement in cytotoxic activity for resulting analogues was observed. Careful observation revealed that when analogue 4 was arylated with benzoyl group having an electron donating substituents, showed significant enhancement in the cytotoxicity for the resulting analogue 11, while, the compound 4 when arylated with benzoyl group having electron withdrawing substituent such as analogue 12, it slightly decreased the activity in comparison to analogue 11. Similarly when compound 4 was acylated with hydrocarbons with small to moderate chain size (C 3 -C 12 ), the activity also increased drastically for all the five tested human cancer cell lines in comparison to the starting material, loganin, but when the length of hydrocarbon increased (above C 12 ) the activity of resulting compounds decreased drastically. Interestingly introduction of a double bond in the aliphatic chain such as in case of analogue 9, totally abolished the activity. But it was interesting to note that introduction of a gem dimethyl group in the terminal carbon of the double bond in the above analogue 9, resulted in the significant enhancement of anticancer activity as depicted in analogue 10. It might be due to the enhancement in the bulkiness and/or lipophilicity of the molecule due to increase of two more methyl groups.
[0070] On comparing our results with the known anticancer drug, vinblastine it was observed that two semi synthetic analogues 6 and 11 showed 13 times higher activity against the human suspension colon (COLO-320) cancer cell lines while analogue 11 showed 8 times higher activity against human adherent colon cancer cell line (CaCO2) than those for vinblastine.
TABLE 1 Anticancer activity of loganin (1) and its derivatives 2-12 (μg/ml) by MTT assay against human cancer cell lines. COLO- Dosage MCF-7 PA-1 WRL 320 CaCo2 range Compounds IC 50 IC 50 IC 50 IC 50 IC 50 IC 50 1 4.85 1.45 1.86 1.00 1.28 1.0-5.0 2 1.00 0.65 1.86 0.25 0.56 0.25-2.0 3 1.20 1.20 2.44 0.82 3.45 0.80-3.5 4 IA IA IA IA IA — 5 1.88 1.24 2.65 0.85 2.85 0.80-3.0 6 0.24 0.15 0.85 0.04 0.42 0.04-0.85 7 24.60 6.5 58.50 30.00 IA 6.5-59.0 8 IA IA IA IA IA — 9 IA IA IA IA IA — 10 1.00 0.65 1.20 0.08 0.80 0.08-1.20 11 0.25 0.10 0.54 0.04 0.06 0.044-3.54 12 1.25 0.85 3.20 0.44 1.00 0.44-3.20 Vinblastine 0.02 0.025 1.45 0.52 0.46 0.02-1.45 IA = Inactive
|
The present invention provides novel loganin analogues and a process for the preparation thereof. The present invention further provides the use of Iridoid glycoside loganin isolated from the fruit pulp of Strychnos nux - vomica and its bioactive semi-synthetic analogues against various human cancer cell lines grown in-vitro.
| 2
|
BACKGROUND OF THE INVENTION
This invention relates to flow control, and, more particularly to the control of fluid flow for in-line applications.
In many situations it is necessary to control the in-line flow of fluids such as liquids and gases. A common device for that purpose is a variable clamp. It functions by squeezing the line to constrict the opening through which the fluid passes. It requires that the line have sufficient resiliency to recover when the clamping pressure is removed. The objection to the clamping technique is that it cannot be used with relatively rigid conduits. In addition, the control that is exercised over fluid flow by clamping is imprecise.
Attempts have been made to overcome the foregoing difficulties by the use of valves which are placed in the line. Such valves tend to be complex and expensive. They are usually imprecise in their operation. They frequently provide an initial flow surge and are characterized by dead space. In addition they tend to drift and do not have a stable set position. The principal objection however is that they usually provide imprecise control over flow and are not able to provide flow control over a wide range. Typical flow control devices of the prior art are those illustrated in the following patents:
______________________________________ Patent No. Issued Inventor______________________________________4,073,314 2/14/78 Speelman, et al.3,943,969 3/16/76 Rubin, et al.3,659,573 5/2/72 Bennett3,503,418 3/31/70 Petrucci, et al.3,255,774 6/14/66 Gallagher, et al.______________________________________
Accordingly, it is an object of the invention to facilitate the control of fluid flow. A related object is to facilitate the control of fluid flow for in-line applications.
A further object of the invention is to overcome the difficulties associated with prior flow control valves. A related object is to avoid the difficulties associated with clamping type valves.
Still another object of the invention is to avoid initial flow surge in flow control valves, as well as a reduction in dead space in flow control valves.
Yet another object of the invention is to provide a flow control valve with fine metering as well as repeatable flow adjustments. Still another object is to achieve stable locking with reduced drift. A further object is to provide a comparatively broad range of flow control adjustment.
SUMMARY OF THE INVENTION
In accomplishing the foregoing and related objects, the invention provides for the exercise of flow control using a metering plug that is restricted to movement along the longitudinal axis of a control channel. This avoids the disadvantages of clamping valves and valves with variable positionable disks.
In accordance with one aspect of the invention, closure control is exercised by moving the plug with a micrometer adjustable control ring. This brings the plug into controllable proximity with a tapered channel that has a profile which mates that of the plug.
In accordance with another aspect of the invention, the valve can be produced by the injection molding of plastic parts without parting lines and their attendant disadvantages. The valve is readily assembled using an "O" ring between a base connector and a mating transitional section containing a tapered channel.
In accordance with still another aspect of the invention, the transitional section contains internal passages that accommodate positioning fins on the metering plug to promote the accuracy of the controlled spacing between the transition section and the plug.
In accordance with yet another aspect of the invention, the base connector also includes guide channels that receive positioning fins of the metering plug to provide enhanced control over flow. In addition, the valve desirably includes an adjustable flow control ring that moves the transitional member with respect to the base member. The former is engaged by the flow control ring through a lock ring on the transitional member which is advantageously secured by ultrasonic bonding.
DESCRIPTION OF THE DRAWINGS
Other aspects of the invention will become apparent after considering several illustrative embodiments taking in conjunction with the drawings in which:
FIG. 1 is a perspective view of the a control valve in accordance with the invention;
FIG. 2 is a cross-sectional view of the control valve of FIG. 1;
FIG. 3 is a perspective view of an alternative control valve in accordance with the invention; and
FIG. 4 is a cross-sectional view of the control valve of FIG. 3.
DETAILED DESCRIPTION
With reference of the drawings, an illustrative control valve 10 in accordance with the invention is shown in FIG. 1.
The control valve 10 is formed by complementary body members 20 and 30 which are connectable between sections 50-1 and 50-2 of a line 50 as shown in FIG. 2.
Returning to the overall configuration of the control valve 10 in FIG. 1, a transitional body member 20 is movable with respect to a base member 30 by a micrometer adjustable flow ring 40. The flow ring is rotationally secured to the body member 20 by a lock ring 21. The flow ring 40 includes on its periphery a set of graduations 42 that permit the accurate positioning of the transitional section 20 with respect to the base section 30 with reference to an indexing mark 31 on the base section 30. The flow ring 40 also includes a knurled periphery 43 to facilitate a gripping engagement with the control ring during adjustment operations. The base member 30 includes a similar knurled periphery 33. In the adjustment operation the knurled periphery 33 is gripped by the fingers of one hand and the knurled periphery 43 is gripped by the fingers of the other hand. The two parts 40 and 30 are rotated relative to one another to the desired setting. In practice, as indicated in FIG. 2, the neck 32 of the base 30 is fixed in a tubing section 50-2 so that only the control ring 40 is movable. Similarly, the neck 22 of the transitional member 20 is fixed in a tubular section 50-1 as indicated in FIG. 2. Flow through the valve 40 is in the direction indicated by the arrows A.
The internal constructional details of the valve 10 are set forth in FIG. 2. Control is principally exercised by a metering plug 60 which rests initially in a recessed cup 34 of the base member 30. When the control ring 40 is elevationally rotated with respect to the base 30, it carries the transitional section 20 away from the cup region 34 and thus increases the interval between the taper of the metering plug 60 and the corresponding internal taper of the member 20. The plug 60 includes positioning fins 61 which are located within corresponding recesses 22 of the section 20. Similarly, the fins 61 also are positioned with respect to recesses 35 of the base member 30. In addition, the plug 60 contains channels 62 which provide ingress into the outgoing channel 52 from the incoming channel 51. The desired seal between the members 20 and 30 for longitudinal movements is provided by an "O" ring 63. The various parts are assembled by positioning the metering plug 60 in the base of the base member 30 and then sliding the transitional member 20 over the plug onto the base. This is followed by threading the flow ring 40 onto the base member 20 and applying a lock ring 21 near the base of the neck of the transitional member to provide a surface that is engaged by the flow ring 40 during micrometer adjustment operations. The lock ring is desirably secured to the connector 20 by ultrasonic bonding and there are supplementary locking ribs 24 provided to promote the desired locking action.
An alternative control valve 10' is shown in FIG. 3. The valve 10' is formed by complementary body members 20' and 30' which are connectable between sections 50-1 and 50-2 of the line 50 as shown in FIG. 4.
In the overall configuration of the valve 10' in FIG. 3 the body member 20' is movable with respect to the other member 30' by a micrometer adjustable flow ring 40'. The flow ring 40' includes on its collar a set of graduations 42' that permit the accurate positioning of the transitional section 20' with respect to the base section 30'. The collar is movable with respect to an indexing mark 21' through 360° reaching a stop 26' when fully open. The flow ring 40' also includes flutings 43' on its lower portion to facilitate gripping during adjustment operations. The transitional member 20' includes similar flutings 25' to promote gripping. In the adjustment operation the flutings 43' are gripped by the fingers of one hand and the similar flutings 25' are gripped by the fingers of the other hand. The flow ring 40' is then rotated to the desired setting.
The internal construction details of the valve 10' are shown in FIG. 4. Control is effected by a metering plug 60' which is in two parts 61' and 62'. The part 61' is press fit into the part 62' which includes a flow channel 62f' provided by sections which are spaced apart according to the desired channel width and held apart by the member 61'. The plug 60' formed by the combination of the parts 61' and 62' is press fit into the base member 30' and serve to position a sealing "O" ring 63' with respect to the transitional member 20'. The base member 30' includes recesses 34' which receive fingers 27' of the member 20'.
In the assembly of the valve 10', once the O ring 63' has been positioned on the neck of the member 30' and the plug 60' has been seated in the channel of the base member 30', the transitional member 20' is located on the base member 30' with the fingers 27' in the recesses 34'. A ring portion 43' is then threaded onto the base member 30' at thread positions 44'. A retaining portion 41' is then positioned over the transitional member 20' and ultrasonically sealed to the ring 43' at an interface 46'. The valve 10' is then ready for operation.
While various aspects of the invention have been set forth by the drawings and specification, it is to be understood that the foregoing detailed description is for illustration only and that various changes in parts, as well as the substitution of equivalent constituents for those shown and described may be made without departing from the spirit and scope of the invention as set forth in the appended claims.
|
Method and apparatus for the control of fluid flow using a metering plug that is positioned in a control channel and restricted to movement along the longitudinal axis of the channel. Closure control is exercised by moving the plug with a micrometer adjustable control ring into closer proximity with a tapered channel that has a profile corresponding to that of the plug.
| 8
|
[0001] The present invention is directed to a camouflage tire suitable for use in various vehicle use environments wherein it is desirable to reduce or eliminate a viewer's visual perception of the tire against the given environmental background.
BACKGROUND OF THE INVENTION
[0002] Vehicles for military and recreational use often are camouflaged to reduce the ability of a viewer to perceive the vehicle in a given environment. For example, military trucks are often colored in suitable camouflage patterns having various areas of green, brown, tan, black, etc. that are arranged to allow the vehicle to blend in with a forested or mountainous environment. Alternatively, the vehicle may be colored white to blend in with a snowy or arctic type environment, or the vehicle may be colored tan, brown, or various shades of pink to blend in with a desert or grassland environment. The particular shades of colors used and the camouflage pattern depend on the vehicle use environment.
[0003] While camouflage of vehicle parts such as the body panels is routine, camouflage of tires has not been successfully accomplished. The use of a typically black tire on an otherwise camouflaged vehicle may leave the vehicle susceptible to visual detection, due to the contrast of the black tires with the environmental background. It would therefore be desirable to have a tire camouflaged with a suitable color and/or pattern that will reduce or eliminate the visual perceptibility of the tire when mounted on a vehicle in a given environment.
SUMMARY OF THE INVENTION
[0004] The present invention provides a camouflaged tire, wherein the tire comprises a surface pattern such that the visual perceptibility of the tire against a given environmental background is reduced as compared to a standard, black tire.
[0005] In one embodiment, the camouflaged tire comprises a multicolored pattern suitable for use in a forest or mountainous region or the like.
[0006] In another embodiment, the camouflaged tire comprises a monochromatic pattern suitable for use in a snowy or arctic region or the like.
[0007] In yet another embodiment, the camouflaged tire comprises a monochromatic pattern suitable for use in a desert or grassland region or the like.
[0008] The camouflage tire may comprise a flexible, elastomeric coating applied to a cured tire. The coating may comprise one or more colorants to provide the camouflage tire with the desired camouflage pattern. The coating may be applied to the tire in one or more layers to provide one or more areas of color on the surface of the camouflage tire, resulting in a suitable camouflage pattern usable in a given environment.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The camouflage tire comprises a tire having at least one external surface, and a coating applied to the at least one external surface. The coating may include colorants to give the camouflage tire a suitable appearance and function such that the camouflage tire will have a reduced visual perceptibility when viewed against the background of a given environment.
[0010] The camouflage tire may comprise any vehicle tire as is known in the art. In one embodiment, the camouflage tire may comprise an all terrain vehicle (hereinafter referred to as ATV) type tire suitable for use on an ATV type recreational vehicle such as the Sportsman 500 and Sportsman 6×6 made by Polaris and the like, and ATVs made by Yamaha and the like. In another embodiment, the camouflage tire may comprise a truck or jeep tire suitable for use on commercial or military trucks, Jeep® type vehicles, Hummer® type vehicles, or other vehicles such as sport utility vehicles (hereinafter referred to as SUV), pickup trucks, off road earth moving vehicles and the like. Any tire usable in a manner in which the user desires a reduced visual perceptibility of the tire against a given environmental background may be used in the camouflage tire.
[0011] The camouflage tire may further comprise a coating applied to at least one external surface of the tire. A coating may be applied to any or all external tire surfaces, including the bead, sidewall, and tread surfaces of the tire. In one embodiment, the coating is applied coextensively over the entire external surface of the tire.
[0012] The coating applied to the tire external surfaces may be any suitable coating material that will adequately adhere to the tire surface and suitably resist peeling, cracking, and sloughing from the tire. In one embodiment, the coating is a liquid solution of at least one elastomer in a water or solvent based carrier.
[0013] In one alternative embodiment, the coating may be applied as a water based elastomer liquid. The elastomer may be dispersed as finely divided polymer particles in the water based carrier as an emulsion or latex comprising various suitable additives including surfactants, preservatives, and colorants. Other additives may be included in the water based elastomer liquid as are known in the art. The water based elastomer may be used as a one part coating application or as part of a two-part application. In one embodiment, the water based elastomer may be used as a one part coating wherein suitable curing agents are included to promote crosslinking or otherwise cure the elastomer coating. In another embodiment, the water based elastomer may be used a part of a two part application, wherein suitable curing agents are contained separate from the water based elastomer, and mixed with the water based elastomer immediately prior to application on the tire external surface.
[0014] In another embodiment, the coating may be applied as a solvent based liquid. The elastomer may be partially or completely dissolved or swelled in a suitable organic solvent. Suitable solvents include but are not limited to various organic solvents as are known in the art such as cyclohexane, hexane, heptane, octane, decane, dodecane, methylene chloride, chloroform, and the like; and various aromatic solvents such as toluene and the like; halogenated aromatics, various Tolusols generally containing C 7 hydrocarbons and significant amounts of aromatic compounds therein, xylene, dichlorobenzene, and the like; diphenyl ether, and the like; ketones including acetone, methyl ethyl ketone, methyl isobutyl ketone, and the like; and alkyl esters such as ethyl acetate, methyl acetate and the like. Solvents may be used singly or as a mixture of one or more solvents. The solvent based elastomer liquid may be used as a one part coating application or as part of a two-part application. In one embodiment, the solvent based elastomer may be used as a one part coating wherein suitable curing agents are included to promote crosslinking or otherwise cure the elastomer coating. In another embodiment, the solvent based elastomer may be used a part of a two part application, wherein suitable curing agents are contained separate from the solvent based elastomer, and mixed with the solvent based elastomer immediately prior to application on the tire external surface.
[0015] One suitable solvent based elastomer is available commercially under the name EnduraLast from the Lord Corporation. This material may be modified through the addition of suitable colorants to obtain the colors desirable in a camouflage pattern on a tire.
[0016] The elastomer usable in either a water based or solvent based coating may be any suitable elastomer that will form a uniform coating on the external surface of the tire and will resist cracking, peeling or sloughing from the surface. In one embodiment, the elastomer may comprise one or more crosslinkable thermoplastic elastomers as are known in the art including natural or synthetic rubber, halogenated rubbers, polyurethanes, polyacrylics, polyacrylates, chloropolymers, fluoropolymers, and the like. The elastomer may alternatively comprise EPDM, silicone rubber, polychloroprene, epichlorohydrin, acrylonitrile rubber, hydrogenated acrylonitrile rubber, zinc salts of unsaturated carboxylic acid ester grafted hydrogenated nitrite butadiene elastomer, natural rubber, synthetic polyisoprene, styrene-butadiene rubber, 1,4-trans-polybutadiene, ethylene-vinyl-acetate copolymer, ethylene methacrylate copolymers and terpolymers, chlorinated polyethylene, chlorosulfonated polyethylene, alkylated chlorosulfonated polyethylene, trans-polyoctenamer, polyacrylic rubber, and the like, and mixtures thereof.
[0017] The elastomer may be present in the water based or solvent based coating liquid in a concentration suitable to facilitate application of the coating to the tire surface and allow relatively rapid removal of the water or solvent carrier by drying or evaporation or the like. In one embodiment, the elastomer may be present in the water based or solvent based coating liquid in a range of about 10 to about 90 percent by weight.
[0018] The water based or solvent based coating liquid may comprise one or more cure agents as is required to obtain a cured coating on the camouflage tire. Such cure agents may include but are not limited to well-known classes of peroxides including diacyl peroxides, peroxyesters, dialkyl peroxides and peroxyketals. Specific examples include dicumyl peroxide, n-butyl-4,4-di(t-butylperoxy) valerate, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-butylperoxy) cyclohexane, 1,1-di(t-amylperoxy) cyclohexane, ethyl-3,3-di(t-butylperoxy) butyrate, ethyl-3,3-di(t-amylperoxy) butyrate, 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, t-butyl cumyl peroxide, a,á-bis(t-butylperoxy)diisopropylbenzene, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy) hexyne-3, t-butyl perbenzoate, 4-methyl-4-t-butylperoxy-2-pentanone and mixtures thereof Cure coagents may also be present. Such coagents include but are not limited to triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallyl trimellitate, diallylidene pentaerithryte, diallyl terephthalate, tetraallyl oxyethane, triallyl citrate, acetyl triallyl oxyethane, acetyl triallyl citrate, di-, tri-, tetra- and penta-functional acrylates, di-, tri-, tetra- and penta-functional methacrylates, n,n′-m-phenylene-dimaleimide, 1,2-cis-polybutadiene and mixtures thereof. Cure agents may be added to the coating liquid in an amount suitable to facilitate crosslinking or otherwise cure of the elastomer as is appreciated by one of skill in the art without undue experimentation.
[0019] The water based or solvent based coating liquid may comprise one or more colorants as are desired to impart a given color or pattern to the camouflage tire. The color imparted by the colorants is not limited and may include any color obtainable with known colorant additives. The colorants may include any suitable dyes, pigments, or the like that impart the desired color. The colorants may be included in the water or solvent based coating liquid or mixed with the coating liquid immediately prior to application to the tire. The relative amount of colorant to be added to the coating liquid is dependent on the type of colorant, the desired color, and the desired intensity of the color, as would be appreciated by one of skill in the art without undue experimentation.
[0020] Dyes are generally defined as compounds which contain groups that confer color, generally called chromophores. More information on dyes in general is available in The Chemistry of Synthetic Dyes , Volumes I and II by K. Venkaktaraman, 1952, published by Academic Press, Inc., New York, and in Organic Chemistry by W. T. Caldwell, 1943, published by Houghton Mifflin Company in its chapter entitled “Synthetic Dyes,” Pages 702 through 725.
[0021] The coating compositions of the present invention also may contain color pigments, including inorganic pigments, such as. titanium dioxide, talc, mica, iron oxides, lead oxides, chromium oxides, lead chromate and carbon black, including conductive carbon black, and organic pigments such as phthalocyanine blue and phthalocyanine green, as well as a variety of other color pigments.
[0022] The water based or solvent based coating liquid is applied to one or more external surfaces of a tire by any of various application methods as are known in the art, including spraying, brushing, rolling, submersion, and dipping, wiping, and the like. In one embodiment, the water based or solvent based coating liquid is sprayed onto one or more external surfaces of the tire. The spray is applied manually or automatically using spray application devices as are known in the art.
[0023] To promote adhesion of the applied coating, the external surfaces of the tire may require preliminary preparation prior to application of the water based or solvent based coating. In one embodiment, the external tire surfaces may be cleaned of dirt, oils, and other contaminants using an aqueous detergent solution or other cleaning material. Mold release agents such as silicone mold release agents that may interfere with adhesion may be removed using solvents such as alcohols and the like. The external tire surfaces may further be prepared by application of a suitable primer material. In one embodiment, the external tire surface may be coated may be pretreated with a chlorinating agent such as sodium hypochlorite and hydrochloric acid, or with a cyanuric acid solution. One example of a chlorinating agent is commercially available under the tradename Chemlok® 7701. The primer may be applied to the surface of the elastomeric material by brushing, dipping, spraying, wiping, or the like, after which the primer is allowed to dry.
[0024] To further promote adhesion of the coating to the tire surface, the tire rubber may comprise particular agents that promote adhesion. One such approach is taught in U.S. Pat. No. 4,669,517, fully incorporated herein by reference, wherein it is disclosed to add at least one hydroxyl terminated diene polyol to the tire rubber compound to promote adhesion.
[0025] As a further way to promote adhesion, it may be desirable if making the camouflage tire to use a tire produced without the use of silicone type mold release agents. Such agents as are typically used in manufacture of tires may interfere with the adhesion of the elastomer coating.
[0026] After any preliminary surface preparation and priming, the water based or solvent based coating material may be applied to the one or more external tire surfaces by one of the aforementioned methods. In one embodiment, the coating material containing suitable colorant and curing agents is sprayed onto at least part of all entire external surfaces of the tire. The coating solution is applied in a manner sufficient to give a coating over part or all of the external surface of the tire, where the thickness of the coating when cured is suitable to prevent cracking, peeling, and sloughing from the tire surface. In one embodiment the coating thickness may be from about 0.1 to about 2 microns. In another embodiment, the coating thickness may be from about 0.25 to about 1 microns.
[0027] The coating solution may be applied in one or more layers as is needed. In one embodiment, a camouflage pattern having two or more colors may require sequential application of two or more layers of coating solution, with each layer having the same or different colorant to obtain the desired pattern. Each subsequent layer may be applied to part or all of the external tire surface, to obtain a plurality of color regions which in total comprise a desired camouflage pattern. Subsequent applications of the coating materials may require a slight time delay to allow for drying or partial cure of the previous layer.
[0028] In one embodiment, the camouflage tire may be a camouflage ATV tire suitable for use in a forest or mountainous region. The camouflage ATV tire suitable for use in a forest or mountainous region may comprise two or more colored regions on the surface of the tire, which may be applied by sequential spraying of layers of water based or solvent based coating liquids. The camouflage ATV tire may be preliminarily cleaned with a detergent solution to remove dirt and oils, alcohol to remove any silicone mold release agents, and all external surfaces primed with a suitable primer. A first layer may be applied as a continuous layer of black colored elastomer liquid to give a continuous layer of black over the bead, sidewalls, and tread. Next, one or more regions of color such as olive drab, yellow, or tan colored elastomer liquid may be sprayed over parts of the black layer to give a plurality of regions of color as is required to give the desired camouflage pattern. The plurality of color regions may overlap and may extend over one or more external surfaces. The color regions applied subsequent to the initial black layer may extend over at least a part of the external surface of the camouflage tire.
[0029] The water based or solvent based coating liquid may be applied to give camouflage tires having a camouflage pattern that meets military specifications. Alternatively, the camouflage pattern may be any pattern that is suitable to satisfy the aesthetic desires of the user, or to provide a camouflage tire having reduced visual perceptibility against the background of a given use environment.
[0030] In another embodiment, the camouflage tire may have a camouflage pattern comprising a single color to make the camouflage tire suitable for use in an relatively monochromatic environment. For example, camouflage tires suitable for use in a snowy or arctic environment may be white or a variation thereof over the entire external surface. Camouflage tires suitable for use in a desert or grassland environment may be tan, salmon, or pinkisk or some variation thereof over the entire external surface. Thus, the camouflage pattern on the camouflage tire may comprise one or more regions of color as is need for use in a particular environment.
[0031] For camouflage tires suitable for use in environment where a monochromatic tire is desirable, the tire rubber may be made using a non-black filler and without carbon black. Typically, black tires comprise a black filler such as the various carbon blacks as are known in the art. In the case of a camouflage tire having a white, tan, or otherwise monochromatic hue other than black, a non-black filler may be used. Such non-black fillers include the silicas, clays, and other non-black fillers as are known in the art.
EXAMPLE 1
[0032] In this example, several physical properties of an applied camouflage coating on an ATV were measured. Camouflage coating was applied to standard ATV type sidewall and tread compounds. The samples were tested for various properties to characterize the strength of the film as well as the ability of the film to resist environmental factors.
[0033] For the camouflage colors, the compound testing was run on ATV tread and sidewall compounds. Lab samples were cured and then coated using the green and brown coatings used on the camouflage tires. It is believed that the coating material was substantial the same as the EnduraLast tire coating available from Lord Corporation, with modification to include suitable colorants.
[0034] The initial camouflage coating showed a greater propensity of cracking in the kinetic ozone test and a lower fatigue resistance. All other physical properties were equivalent to the uncoated samples, including static ozone and cyclic dynamic ozone testing. The cracking on the kinetic ozone test was not seen on the passenger samples that were coated.
[0035] There was some discoloration of the samples noted after ozone testing.
[0036] Results of the physical properties testing is shown in Tables 1 and 2.
TABLE 1 Matis 2002000422 284726 284728 284725 N150F w/ 284727 K234C w/ N150F Paint K234C Paint UTS 300% Modulus 5.35 5.21 5.38 5.42 Tensile 11.44 13.46 16.42 13.89 Elongation 562 626 701 664 #95 Monsanto Cyclic 1554 56 1440 86 Fatigue Cam 14 Penetration Energy (J) 0-5 mm 0.076 0.079 0.083 0.085 0-20 mm 2.645 2.645 2.756 2.793 Bent Loop Ozone ok ok ok ok Kinetic Ozone (60%) not broken broken not broken broken Dynamic Cyclic Ozone 2 days 4 days 6 days 5 days (25%) to break to break to break to break Dynamic Cyclic Ozone 7 days 7 days 10 days 8 days (25%) Aged 3 days @90 C. in to break to break to break to break oven Dynamic Cyclic Ozone 10 days 14 days 13 days 12 days (25%) Aged 3 days @90 C. in to break to break to break to break water (Note some change in color)
[0037]
284726
284728
284725
N150F w/
284727
K234C w/
N150F
Paint
K234C
Paint
#95 Monsanto Cyclic
1366
1041
1440
1175
Fatigue Cam 14
EXAMPLE 2
[0038] In this example, ATV tires were painted in camouflage. Three front tires (AT25×8−12 Rawhide Grips) and three rear tires (AT25×10−12 Rawhide Grips) were coated. The tires were coated in a forest camouflage, consisting of green, brown and black and a desert camouflage consisting of tan, brown, and black. One rear and one front tire were only painted on the sidewall, whereas the other 4 tires had the entire tread and sidewall surface coated. Tires were cleaned, then coated with the black coating to give a consistant color. The other two colors were sprayed on to achieve the camouflage effect. The coating process was completely manual. It is believed that the coating material was substantial the same as the EnduraLast tire coating available from Lord Corporation, with modification to include suitable colorants.
[0039] Tires were run on an ATV endurance test in order to determine the durability of the coating. The tires were run 300 miles on an off road course and powerwashed at 25 mile intervals. Then the tires were run through a mud pit for 1 hour and powerwashed at 15 minute intervals. This test simulates about 1 season/1 year of use of fairly strenous use by a customer.
[0000] First Test:
[0040] The coating was already wearing off the tread area after only 50 miles. The tires with only the sidewall coated looked better after wear. It was decided that only the sidewall would be coated for future tests and we would not pursue coating the entire tread area. There was noted flaking and peeling of the coating on the sidewall. Upon inspection of the tested tires it was determined that the peeling was due to poor adhesion of the coating.
[0041] The front tires saw more scuffing of the coating than the rear tires. In general, the front tires will see more wear. However, the rear tires also had a scuff rib which may have helped protect the sidewall. It was decided in future tires, a front tire design with a scuff rib would be tested to determine if it would help protect the sidewall from scuffs.
[0000] Second Test:
[0042] Front—cleaned, Tracker P with scuff rib cleaned, Rawhide Grip—no scuff rib
[0043] Rear—cleaned, Rawhide Grip with scuff rib not cleaned but cured without pre-cure paint and mold release, Rawhide Grip w/scuff rib
[0044] Coating was slightly modified from first test to be more flexible. Tires were cleaned with isopropyl alcohol before coating. The one tire that was not cleaned showed a considerable amount of peeling despite the fact that it did not have any pre-cure paint or mold release on it. This suggests that the waxes used as protectants in the sidewall compound which bloom to the surface may also contribute to the lack of adhesion of the coating if not cleaned immediately prior to the application. The cleaned tires showed no sign of flaking or peeling at the end of the test.
[0045] The scuff rib on the front tire did make a marked improvement in protecting the sidewall from scuffs.
[0046] After testing the coating was intact with only some scuffs. The scuffs were deemed acceptable without the peeling.
|
The present invention is directed to a camouflage tire suitable for use in various vehicle use environments wherein it is desirable to reduce or eliminate a viewer's visual perception of the tire against the given environmental background.
| 1
|
COPYRIGHT AUTHORIZATION
[0001] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of software development, and more particularly, to a web-based workflow automation system.
BACKGROUND
[0003] A workflow defines a sequence of tasks to be performed to achieve an objective. Examples of workflows include workflows for business processes (e.g., processing insurance claims, payroll), and various manufacturing and fabrication processes.
[0004] Although various workflow tools have been developed, these tools suffer from deficiencies including lack of a unified platform for designing, configuring and administering the workflows. Moreover, conventional workflow tools, such as the Windows Workflow Foundation (WF) and Microsoft BizTalk Server (“BizTalk”) require highly skilled technicians to design and configure solutions. For example, Windows Workflow Foundation (WF) requires writing declarative workflows (a programming skill) and knowledge of the .NET Framework. BizTalk relies heavily on a combination of programming utilizing the Microsoft Visual Studio toolset and a Windows-based interface. Moreover, involvement and intervention of system administrators is usually necessary.
SUMMARY OF THE INVENTION
[0005] According to the methods and systems of the present invention, a web-based workflow automation system for developing event-based workflows is provided. The workflow automation system enables users with little or no programming knowledge to easily create and schedule event based workflows utilizing a web based interface. The workflow automation system provides a unified platform for project and workflow creation, execution, and testing.
[0006] As used herein, a workflow refers to a sequence of activities. The execution outcome of an activity determines, either alone or in combination with another activity, the activity or activities that will be executed next (if any) in the workflow. By convention, the initial activity in a workflow is a Start activity. Construction of the workflow includes assigning a set of properties for the project and each set of activities in the workflow, each set of the properties based on a template. Once the workflow is constructed, the workflow can be executed on an ad hoc basis or as scheduled. In an embodiment, a Default environment is built in and does not support project execution or scheduling but can be used by a developer to define project and activity properties capable of being inherited in other environments.
[0007] A notable feature of the present invention is the inclusion of a user interface element referred to herein as a property grid wherein property values for a project, an activity, or a schedule can be user-defined. The property grid has a uniform layout, such as a tabular layout in which each row can be used to input a property value for a property. The property grid supports input of an absolute value, a reference, or an expression. Where the property value is a reference, the reference is automatically reflected across all property values which consume the reference. An expression may be written in various ways, including in the syntax of a supported high-level programming language (such as C#). Additionally, a look-up mechanism is provided for extracting and displaying historical property values so that they are selectable for input. Preferably, the property grid includes rows having one or more GUI widget for inputting/selecting an appropriate property value or indicating whether a property value is to be inherited or overridden.
[0008] These and other aspects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 shows a block diagram illustrating the environment-project-workflow hierarchy, as these concepts are used in the present invention;
[0010] FIG. 2 shows an exemplary diagram of a web-based workflow automation system, according to a preferred embodiment of the present invention; and
[0011] FIG. 3 to FIG. 22 show various exemplary screens illustrating aspects of the web-based workflow automation system, according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0012] FIG. 1 illustrates the relationship between an environment, a project, and a workflow, as these concepts are employed herein. As shown, an environment can include a project, and a project, in turn, can include a workflow.
[0013] As used herein, an environment relates to the collection of resources and policies associated with a stage of development.
[0014] As used herein, a project is a management construct for an endeavor planned and designed to achieve a particular outcome. A project includes development of at least one workflow which can be executed on an ad hoc basis or scheduled.
[0015] As used herein, a workflow refers to a sequence of activities. The execution outcome of an activity determines, either alone or in combination with another activity, the activity or activities that will be executed next (if any) in the workflow. By convention, the initial activity in a workflow is a Start activity.
[0016] As used herein, an activity refers to a task which is capable of being performed using a general purpose computer, a hardware device with firmware and/or software, and/or an electro-mechanical device with a microcontroller (e.g. robotic arm).
[0017] As used herein, a schedule refers to the points in time when the Start activity of a workflow will be performed.
[0018] As used herein, a project domain refers to the general category of a project.
[0019] As used herein, the Default environment refers to a built-in environment that does not support project execution or scheduling but can be used by the developer to define project, activity or schedule (as the case may be) properties capable of being inherited in other environments.
[0020] As used herein, a property refers to one of a set of characteristics established or inherited regarding a project, an activity or a schedule.
[0021] As used herein, a property value refers to the value of a property which can be an absolute value, a reference, or an expression.
[0022] As used herein, a property grid refers to a user interface element in which property values for a project, activity or schedule (as the case may be) can be user-defined. The property grid has a consistent layout and look and feel although the contents change depending on the project, activity or schedule selected.
[0023] Referring to FIG. 2 , an exemplary diagram of a web-based workflow automation system 100 is shown. As depicted, the workflow automation system 100 includes a distributed application which is partitioned between a service provider (server 120 ) and a plurality of service requesters (clients 140 ). Under this arrangement, a request-response protocol, such as hypertext protocol (HTTP), can be employed such that a client 140 can initiate requests for services from the server 120 , and the server 120 can respond to each respective request by, for example, executing an application 125 on the server 120 , and (where appropriate) sending results to the client 140 . It is to be understood that in some embodiments, however, substantial portions of the application logic may be performed on the client 140 using, for example, the AJAX (Asynchronous JavaScript and XML) paradigm to create an asynchronous web application. Furthermore, it is to be understood that in some embodiments the application 125 can be distributed among a plurality of different servers 120 (not shown).
[0024] Preferably, the illustrated entities (the server 120 and the clients 140 ) communicate via the Internet 150 which provides a path for data communication, and allows exchange of information signals. Although the Internet 150 is depicted as being used for communication among the illustrated entities, it is to be understood that other network elements could, alternatively, or in addition, be used. These include any combination of wide area networks, local area networks, public switched telephone networks, wireless or wired networks, intranets, the Internet or any other distributed processing network or system. In still other embodiments, the workflow automation system 100 can be implemented on a single standalone computer system.
[0025] In the following description of the present invention, exemplary methods for performing various aspects of the present invention are disclosed. It is to be understood that the steps illustrated herein can be performed by executing computer program code written in a variety of suitable programming languages, such as C, C++, C#, Visual Basic, and Java. It is also to be understood that the software of the invention will preferably further include various Web-based applications 125 written in HTML, PHP, Javascript, jQuery accessible by the clients 140 using a suitable browser 145 (e.g., Internet Explorer, Mozilla Firefox, Google Chrome, Opera).
[0026] Project/Activity/Schedule Properties and the Property Grid
[0027] A notable feature of the present invention is the inclusion of a user interface element referred to herein as a property grid wherein property values for a project, an activity, or a schedule can be user-defined. As will be apparent, the property grid has a consistent layout and look and feel although the contents can change depending on the project, activity or schedule selected.
[0028] To illustrate the property grid feature, FIG. 3 shows an exemplary screen including a property grid 130 for defining the properties of a particular “activity”. In this case, the activity is of activity type “SQL Execute Text”, which was selected from a drop-down menu 132 having predefined activity types. The set of activity types available in the drop-down menu 132 will vary depending on the project domain. In this example, the list of activity types will include all of those that typically are employed in the project domain “Information Technology General”. It is to be understood that the property grid 130 is shown for illustrative purposes. Further, it is to be understood that although this example involves a property grid for defining the properties of an activity, property grids used for defining the properties of projects and schedules are also available and have similar features.
[0029] To ensure data integrity, the property grid 130 includes appropriate controls to input data values for each property. In particular, preferably, the property grid 130 can be configured such that the only allowable property values, where appropriate, are an absolute value, a reference (wherein a reference checkbox for the property can be checked) or an expression (wherein an expression checkbox for the property can be checked). Additionally, the input data can be validated for data type compatibility, e.g., where a property value can only be an integer, an alphabetic value would not be accepted.
[0030] Referring to FIG. 4 , an exemplary screen having a property grid 130 in a Production environment is illustrated. As shown, the “Payroll File to Vendor ABC” project is opened, and the user has elected to inherit each of the properties of the selected activity except the “Connection String” property wherein the user has inputted an expression. The value inputted for the “Connection String” property is different from the one assigned to this property in the Default environment. In general, a property value in a non-Default environment (such as the Production environment) can be inherited (wherein the inherited checkbox for the property can be checked) from the Default environment.
[0031] Each property of a project, activity, or schedule is represented in the pertinent property grid by a row. For example, the SQL Execute Text activity type has the properties Result Set Type, Connection String, Command Text, Transform Type, and Result File Name. Where input values for a property are mandatory, a visual indicator, such as a check mark (as shown) is displayed next to the property. As illustrated in FIG. 4 , the Result Set Type, Connection String, and the Command Text properties are mandatory.
[0032] Preferably, an absolute value for a property can be input by un-checking the reference checkbox, the expression checkbox and the inherit checkbox (if applicable). The appropriate control to input an absolute value appears next to the property name.
[0033] Preferably, property values can be edited in any environment. For property values created in the Default environment, the property values are automatically inherited in other environments but can be expressly overridden. Overriding a property value is accomplished by un-checking the inherit checkbox corresponding to the property in the property grid. The property value is then overridden by providing an absolute value, a reference, or an expression.
[0034] Property References
[0035] Property references are used when a particular property value is reused across projects or activities. For example, several projects may need to use the same project type property value Working Folder Path, e.g. C:\Users\arup\Documents\WorkingFolder. If for some reason, the property reference value changes, then the new property reference value is automatically applied for all properties that are using the property reference.
[0036] The Reference checkbox that appears after the Property Name in the property grid is checked while creating or editing a project/activity to indicate a reference. Clicking the reference checkbox changes the value textbox into a drop-down with a list of available references. References are created and managed independently of projects and activities.
[0037] Creating a Property Reference
[0038] FIG. 5 illustrates an exemplary screen for creating a project type property reference. To create a project/activity type property reference, the Workbench tab on the main menu is clicked, followed by the Project/Activity tab followed by the Reference tab and finally the New tab is clicked. A project/activity type is then selected from the Project/Activity Type drop-down list. All properties belonging to the selected Project/Activity Type appear in the Property drop-down list. The property whose reference is to be created is selected from the Property drop-down list. A suitable Property Reference Name is then entered. Depending on the type of the property that has been selected, a suitable input control appears next to the Control field. A suitable value is entered/selected for the Control field. Notes can be entered in the Note field. Checking the Baseline checkbox renders this property reference un-editable. The Add button is clicked to add this Project/Activity Type Property Reference.
[0039] Viewing a Property Reference
[0040] FIG. 6 illustrates an exemplary screen for viewing an activity type property reference. To view a project/activity type property reference, the Workbench tab on the main menu is clicked, then the Project/Activity tab on the Workbench page is clicked. The Reference tab is clicked. And then the Detail tab is clicked. A reference version is selected from the Reference Version drop-down list. The details of the Project/Activity Type Property Reference version appear along with a Dependents section that lists all dependent project versions/activities. The Edit, Delete, Baseline and New Version buttons will appear if the reference version has not been based. Only the New Version button will appear for a baselined reference version.
[0041] Editing a Property Reference
[0042] For those property references that qualify to be edited, the property reference is first viewed (as above) and then the Edit button which appears next to a drop-down list is clicked to edit the property reference. An Update button is clicked to finalize the changes.
[0043] Creating a New Version of a Property Reference
[0044] FIG. 7 illustrates an exemplary screen for creating a new version of a property reference. (Navigation: Workbench tab Project/Activity tab Reference tab Detail tab Reference Version drop-down list). A property reference version is viewed and the New Version button appears next to the drop-down list. A modal confirming the request to create a new version appears. On user confirmation, a new version is created.
[0045] Property Grid Expression Feature
[0046] FIG. 8 illustrates an exemplary screen for setting an expression as a property value. In this example, a Microsoft C# programming language expression that evaluates to a property value is used in the property grid by checking the Expression checkbox. A C# expression is used that evaluates to a value with the same data type as that of the property. The screen illustrates how an out file name can have the current date embedded in the file name. Note that DateTime.Now.Month, DateTime.Now.Day and DateTime.Now.Year are the C# syntax to get the current month, day and year respectively. Although the illustrated example shows a C# expression, it is to be understood that the present invention could support expressions written in other high level languages.
[0047] Environments
[0048] Generally, an environment relates to the policies and available resources under which a project is created, enabled or executed. E.g., Production environments typically have stringent access control, change management, logging, data control, etc., as opposed to development environments. New environments can be added and existing environments deleted in the Administration page. The Default environment does not support project execution. Projects created in the Default environment are visible in other environments and can be enabled or disabled for execution in any other environment. The properties of a project created in the Default environment can be overridden in non-Default environments. However, projects created in a non-Default environment can only be enabled or disabled for execution in their creation environment and are not visible in any other environment. Moreover, schedules can only be created in non-Default environments and are only visible in the environment where they were created.
[0049] Creating a New Environment
[0050] FIG. 9 illustrates an exemplary screen for creating a new environment. To arrive at this screen, the Administration tab on the main menu is clicked. Then, the Environment tab of the Administration page is clicked. The New tab under the Environment tab space is clicked, and the Environment Name and Description are entered. To add the environment, the Add button is clicked. The Detail tab under the Environment tab will be displayed with the new environment details and a “success” message highlighted.
[0051] Projects
[0052] A project is a management construct to achieve a certain objective. A project includes at least one workflow which can be executed via a schedule or on an ad-hoc basis. A project created in the Default environment is automatically inherited across other environments but may be overridden. When a project created in the Default environment is inherited in another environment, all project components (e.g., activities) are also inherited. A project created in a non-Default environment cannot be inherited.
[0053] A project is created by selecting a template from a predefined set of project type templates and then configured by setting the project attributes and property values. Multiple project type templates address different vertical domains. For example, the Information Technology General template addresses a generalized business systems domain for common information technology (IT) activities such as copying files, sending email, encrypting files, etc. Plug-in technology enables project templates for diverse domains and verticals to be integrated seamlessly.
[0054] Change management is achieved utilizing versioning. A newly created project is assigned a “version 1”. A project version is editable until a baseline is created utilizing the Baseline button adjacent to the Project Version drop-down in the Project tab General tab. Clicking the New Version button next to the Project Version drop-down in Project tab General tab also baselines the older version and renders it un-editable in addition to creating a newer version with the same attributes and properties as the older version. Only the latest project version is editable, unless it has been baselined.
[0055] Creating a New Project
[0056] FIG. 10 illustrates an exemplary screen for creating a new project. (Navigation: Workbench tab→Project tab→New tab). Once on this screen, the user enters the Project Name (e.g., “Payroll File to Vendor”), the Effective Date (e.g., 11/29/2011 10:00:00 AM) and Inactive Date (e.g., 12/31/2012 20:00 AM). An appropriate type of project is selected from the Project Type drop-down list. In this example, a project type of Information Technology General has been selected. The properties of the selected project type appear below the drop-down list. The properties of the selected project type are entered, namely the location of the Working Folder Path (“C:\Users\arup\Documents\WorkingFolder”) and Archive Folder Path (“C:\Users\arup\Documents\ArchiveFolder”). To create the project, the Add button is clicked. The Detail tab under the Project tab then will be displayed with the new project details, as shown in FIG. 11 .
[0057] Viewing a Project
[0058] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Project tab→General tab). A project version is selected from the Project Version drop-down list. The project attributes (Baselined, Enabled, Project Type, Note, Effective Date, Inactive Date, Created By, Created Date, Modified By and Modified Date) and project type properties are displayed below the drop-down list.
[0059] Baselining a Project
[0060] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Baseline button). An existing project version is viewed. The Baseline button appears next to the Project Version drop down list if the project version has not yet been baselined and the project is being viewed in the creation environment. The Baseline button is clicked to baseline the project version.
[0061] Deleting a Project
[0062] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Delete button). Project versions that are not baselined can be deleted in their creation environment. An existing project version that qualifies to be deleted is viewed and the Delete button appears next to the Project Version drop down list. The Delete button is clicked to delete the project version.
[0063] Editing a Project
[0064] FIG. 12 illustrates an exemplary screen for editing a project. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Project tab→General tab→Edit button). Baselined project versions cannot be edited. Project versions that have been created in the Default environment and are not baselined can be edited in all environments. Project versions that have been created in a non-Default environment and are not baselined can be edited only in the creation environment. A project version that qualifies to be edited is viewed and the Edit button appears at the bottom. The Edit button is clicked to edit the project version. The Project Type cannot be changed once a project has been created. The project attributes like Project Name, Note, Effective Date and Inactive Date fields can be edited only in the project creation environment. The Project Type properties can be edited in the creation environment. For a project created in the Default environment, the Project Type properties can be overridden in non-Default environments. The Update button is clicked to finalize the changes.
[0065] A notable feature of the present invention is a lookup button 138 which appears at the end of text input boxes. Clicking the lookup button 138 (as shown in FIG. 12 ) brings up a pop-up list 137 (as shown in FIG. 13 ) with absolute values that have previously been used, and a selection from the pop-up list 137 can then be made. Note that a physical copy of the value will be made and stored unlike in the case of reference value where only the reference will be made.
[0066] Enabling/Disabling a Project
[0067] (Navigation: Project tab→Detail tab→Project Version drop-down list→Project tab→General tab→Enable button). Project versions cannot be enabled or disabled in the Default environment since they cannot be executed there. Project versions can be enabled or disabled in non-Default environments by clicking the Enable Project/Disable Project button that appears at the bottom.
[0068] Creating a New Project Version
[0069] (Navigation Workbench tab→Project tab→Detail tab→Project Version drop-down list→New Version button). An existing project version is viewed. The New Version button appears next to the Project Version drop down list if the project version is being viewed in the creation environment. The New Version button is clicked to create a new project version.
[0070] Viewing Project Execution
[0071] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Project tab→Execution tab). An existing project version is viewed in a non-Default environment. The Execution tab under the Project Detail tab space is clicked.
[0072] Activities
[0073] An activity refers to a task which is capable of being performed on a computer or a computer assisted device (e.g. robotic arm). The execution outcome of an activity determines, either alone or in combination with another activity, the activity that will be executed next (if any) in the workflow. The start activity is the root activity or starting point of the workflow. An activity is created by selecting a template from a predefined set of activity type templates and then configured by setting the activity property values. An activity can only be created in the environment the project that it belongs to is created. Properties of an activity created in the Default environment can be overridden in non-Default environments.
[0074] The topics discussed in this section are in context to an existing project version is selected (see Viewing a Project). The Activity tab under the Project tab Detail tab is clicked and tabs to perform various activity related functions appear.
[0075] Creating a New Activity
[0076] FIG. 14 illustrates an exemplary screen for creating a new activity. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→New tab). The New tab under the Activity tab space is clicked. The Activity Name (“Get First Name of Users”) is entered. An appropriate type of activity is selected from the Activity Type drop-down list. In this example, an activity type of SQL Execute Text has been selected. The properties of the selected activity type appear below the drop-down list. The properties of the selected activity type are entered, namely Result Set Type (value of “MultipleRows”), Connection String (reference to “WorkhorseConnectionString, v1”), Command Text (value of “SELECT FirstName FROM USER”), Transform Type (value of “FixedLength”) and Result File Name (value of “FirstNames.txt”). The Add button is clicked. The Detail tab under the Activity tab under the project version gets displayed with the new activity details.
[0077] Viewing an Activity
[0078] FIG. 15 illustrates an exemplary screen for viewing an activity. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Detail tab).The Detail tab under the Activity tab space is clicked. The desired activity is selected from the Activity Name drop-down list. The activity attributes (Enabled, Activity Type and Note) are displayed below the drop-down list. The activity type properties are displayed under the Properties tab and the activity type events are displayed under the Events tab below the drop-down list.
[0079] Viewing Activities
[0080] FIG. 16 illustrates an exemplary screen for viewing an activity. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→List tab). The List tab under the Activity tab space is clicked. All activities that are a part of the project are displayed.
[0081] Viewing UnassignedActivities
[0082] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Unassigned tab). The Unassigned tab under the Activity tab space is clicked. The activities that are not a part of the Start sub-tree are displayed. These activities will not be executed when the project is executed.
[0083] Viewing a Workflow
[0084] FIG. 17 illustrates an exemplary screen for viewing a workflow. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Workflow tab). The Workflow tab under the Activity tab space is clicked. The desired activity sub-tree is selected from the Sub-tree drop-down list. Note that the sub-tree with the Start root node only gets executed during project execution. The non-Start root node sub-trees' are orphans and will not get executed unless they are attached to the Start sub-tree.
[0085] Managing Activity Events
[0086] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Detail tab→Events tab). An existing activity is selected (see Viewing an Activity). The Events tab is clicked. Activity events can be edited for an activity that is editable. If a handler activity exists for an event, the Change button is displayed otherwise an Add button is displayed. The Add/Change button is clicked. The new handler activity or no activity (None option) is selected from a popup list that displays a list of available handler activities. Note that the popup list displays activities that have not already been used as an event handler activity elsewhere. The Update button is clicked to confirm the selection.
[0087] Deleting an Activity
[0088] (Navigation: Project tab→Detail tab→Project Version drop-down list→Activity tab→Detail tab→Delete button). An activity belonging to a project version that is not baselined can be deleted in the creation environment. An existing activity that qualifies to be deleted is viewed and the Delete button appears next to the Activity Name drop-down list. The Delete button is clicked to delete an activity. If other activities depend on an activity, then that activity cannot be deleted.
[0089] Editing an Activity
[0090] FIG. 18 illustrates an exemplary screen for editing an activity. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Detail tab→Edit button). The same rules that apply for editing a project version apply to editing an activity that belongs to the project version. An activity that qualifies to be edited is viewed and the Edit button appears at the bottom. The Edit button is clicked to edit the activity. The Activity Type cannot be changed once an activity has been created. The Activity Name and Note can be edited only in the activity creation environment. The Activity Type properties can be edited in the creation environment. For an activity created in the Default environment, the Activity Type properties can be overridden in non-Default environments. The Update button is clicked to finalize the changes.
[0091] Enabling/Disabling an Activity
[0092] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Activity tab→Detail tab→Edit button). An activity cannot be enabled/disabled in the DEFAULT environment since this environment does not support project execution. An activity can be enabled/disabled in all non-DEFAULT environments by clicking the Edit button and checking or un-checking the Enabled checkbox and then clicking the Update button.
[0093] Schedules
[0094] A schedule is used to execute a project. Workhorse schedules are environment specific and hence can only be created and executed in non-DEFAULT environments. Schedules cannot be inherited across environments and are only visible in the environment that they have been created.
[0095] The topics discussed in this section are in context to an existing project version is selected (see Viewing a Project). The Activity tab under the Project tab→Detail tab is clicked and tabs to perform various activity related functions appear.
[0096] Creating a New Schedule
[0097] FIG. 19 illustrates an exemplary screen for creating a new schedule. (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Schedule tab→New tab). A non-Default environment is selected from the Environment list-box. The New tab under the Schedule tab space is clicked. The Schedule Name (“By-weekly Payroll File Every Other Sunday at 10:30 AM”) is entered. An appropriate type of schedule is selected from the Schedule Type drop-down list. In this example, a schedule type of Recurring Weekly Once a Day has been selected. The properties of the selected schedule type appear below the drop-down list. The properties of the selected schedule type are entered, namely Recurring Frequency (value of “2” indicating by-weekly), Execution Time (reference to “10:30:00 AM”) and Day(s) of Week (value of “Sunday” selected in list box). The Add button is clicked. The Detail tab under the Schedule tab under the project version gets displayed with the new schedule details. The Next Run Date signifies the date and time that this project version will be executed next via this schedule.
[0098] Viewing a Schedule
[0099] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Schedule tab→Detail tab). A non-Default environment is selected from the Environment list-box. The Detail tab under the Schedule tab space is clicked. The desired schedule is selected from the Schedule Name drop-down list. The schedule attributes (Enabled, Next Run Date, Effective Date, Inactive Date, Schedule Type and Note) and schedule type properties are displayed.
[0100] Viewing Schedules
[0101] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Schedule tab→List tab). A non-Default environment is selected from the Environment list-box. The List tab under the Schedule tab space is clicked. All schedules that are a part of the project are displayed.
[0102] Editing a Schedule
[0103] (Navigation: Workbench tab→Project tab→Detail tab→Project Version drop-down list→Schedule tab→Detail tab→Edit button). A schedule that qualifies to be edited is viewed and the Edit button appears at the bottom. The Edit button is clicked to edit the schedule. The Schedule Type cannot be changed once a schedule has been created. The Schedule Type properties can be edited. The Update button is clicked to finalize the changes.
[0104] Event-Based Workflow Supporting Tree-Based Execution
[0105] A project requires an activity of type Start that is used to initiate execution. A typical activity type supports a minimum of four events: Failed, Skipped, Completed and Started. The present invention supports the creation of custom activity types that have more than the four standard events.
[0106] The detail view of an activity has two tabs: Properties and Events. As shown in FIG. 20 , the Events tab displays the events that may occur during the execution of the activity and the handler activities that are executed after each specific event is raised. Note that each activity in a project workflow may be executed at the most one time. Each activity may participate as a handler activity only once excluding the Start activity. The Start activity initiates project execution and hence does not participate as a handler activity.
[0107] FIG. 21 shows an exemplary screen illustrating a workflow to process a payroll file. As illustrated, the Compress Payroll File activity is executed when the activity Get Payroll Data is completed causing the Completed event to be raised.
[0108] Configuration of Events
[0109] Referring to FIG. 22 , activity events are viewed by selecting the Events tab from an activity detail. The Events tab is clicked to view the events that may be raised when the activity is executed and the corresponding activity that will be executed on the generation of any particular event. The Events tab displays a table with rows for each event and an Add/Change button to add or change an event handler activity.
[0110] The Add button is displayed for events that have not yet been assigned an event handler activity. The Change button is displayed for events that have been assigned an event handler activity. Clicking an Add or Change button in the Events view brings up a popup with a list of activities that have not yet been assigned to the workflow.
[0111] To un-assign an event handler activity from an event, the Change button is clicked, the option None is selected from the popup list and the Update button clicked. To reassign an event handler activity, the Change button is clicked, the new event handler activity is selected from the popup list and the Update button clicked.
[0112] Configuration of events is only permissible for activities in their creation environment. For an activity created in the Default environment, configuration of events is only possible in the Default environment and the event configuration is inherited across all other environments where workflow modifications are not permissible.
[0113] Display Context Change Automatically to Reflect Environment Change
[0114] The environment selection list on the top right corner of the main page lists the available environments with the currently active environment selected. When the currently active environment is changed in the environment selection list for a project created in the Default environment, the project and activity attributes, property values and action controls (e.g., Create, Delete, Execute buttons) change automatically to reflect the environment change. Note that a project created in the DEFAULT environment is visible across all environments and the constituent activity property values may be overridden in other environments.
[0115] Entity Relationship (E-R) Diagram Notes
[0116] In the above description of the present invention, exemplary screen layouts were provided to illustrate various features of the present invention. It is to be understood that the processing underlying these screens will necessarily involve storage and retrieval of information related to the environments, projects, activities, workflows and schedules created by the user. Although there are a number of ways in which to organize such information, Appendix A to the present application provides entity-relationship diagrams illustrating the data model used to implement the present invention, according to a preferred embodiment. It is to be understood that various relational database management systems and related technology can be used to implement the storage and retrieval of information for the present invention, according to the entity-relationship diagram presented herein.
[0117] Note: In the following discussion “entities” are shown in bold and italicized.
[0118] The Plugin entity represents a plug-in or snap-on based architecture that allows a PluginType (e.g., Project Type or Activity Type or Schedule Type) to be added to the “Workhorse framework” by just modifying settings and not requiring code changes to the framework. E.g., “Email” is an Activity Type Plugin which is used to send emails. The framework used herein allows properties of the Plugin to be automatically displayed utilizing the Property Grid without requiring additional user interface programming.
[0119] A plug-in is an assembly program that is created utilizing a high level language like C#. E.g., Email is an Activity Type plug-in that is written in a high level language such as C# and contains logic to send email and defines properties that are required to send an email like the sender's and receiver's email addresses, email header, email body, etc. The present framework interprets the properties defined in the Email plug-in and renders these properties appropriately in the user interface as well as captures property values.
[0120] A PluginObject entity represents an actual PluginType (e.g. Project) that is instantiated as is the case when a new project (e.g. when a project called “PayrollProcess” is created). The properties of the PluginObject “PayrollProcess” are represented by the PluginObjectProperty entity.
[0121] The PropertyReference entity represents property references for properties of a Plugin. The PluginObjectPropertyReference entity associates a PropertyReference with a PluginObject (e.g. when “PayrollProcess” project uses a reference “WorkhorseConnectionString” value for a property). The PluginObjectPropertyValue entity represents a property value for a PluginObject (e.g., “C:\Users\arup\Documents\WorkingFolder”).
[0122] The Environment entity represents an execution environment (e.g., “Production”). The PluginObjectEnvironment entity represents a PluginObject in a particular environment (e.g. project “PayrollProcess” in the “Development” environment). The properties and references of the PluginObject in an environment are overridden using the PluginObjectPropertyEnvironment, PluginObjectPropertyEnvironmentValue and PropertyEnvironmentReference entities. The PluginObjectEnvironmentEventLog entity represents logging events that are generated by a PluginObject (project/activity/schedule) during the execution of a project.
[0123] The Project entity is a type of PluginObject that is used to create, execute and mange a workflow. The ProjectEnvironment entity represents a project in a particular environment. An Activity entity is a type of PluginObject used to perform a specific task.
[0124] The ActivityEnvironment entity represents an activity in a particular environment. The ActivityEvent entity represents all possible events that may be generated by an activity and the event handler activities that are executed when a particular event is generated.
[0125] The Schedule entity is a type of PluginObject used for scheduling a project. The Execution entity represents an execution run of a project. The Execution Type entity represents the type of execution (e.g. manual or scheduled). The Variable entity represents a variable that may be defined and used to define property values.
[0126] While this invention has been described in conjunction with the various exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.
Appendix A
[0000]
[0127]
|
A web-based workflow automation system for developing event-based workflows is provided. The workflow automation system enables users with little or no programming knowledge to easily create and schedule event based workflows utilizing a web based interface. The workflow automation system provides a unified platform for project and workflow creation, execution, and testing.
| 6
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a pipe gasket having an asymmetric profile which is made by connecting two ends of an extruded elastomeric material.
The gasket of the invention is used in joining pressure pipe and, more particularly, those pipe with a bell on one end and the other end plain.
2. Description of the Prior Art.
Extruding, cutting and splicing rubber strips of a single hardness and symmetric cross section is well known and many o-rings are made by this process. Such o-rings have round, square, rectangular or other symmetric cross-sectional shapes. Extruding, cutting and splicing of rubber strips of asymmetric cross sections which are made for push-on joint pipe gaskets is not known.
Cast iron pressure pipe with a bell on one end and the other plain or bevelled, have, for many years, been joined by utilizing a rubber gasket which is compressed between the inside walls of the bell and the outside wall of the plain or bevelled end of the next pipe in a series of telescoped pipes. The most successful of such systems provides an elongated retainer groove in the bell with a gasket sealing wall as well as throat and wall portions which guide and limit travel of the plain end as it passes through the bell opening and the rubber gasket. Such a pipe joint is described in U.S. Pat. No. 2,953,398 issued Sept. 20, 1960 and U.S. Pat. No. 4,108,481 issued Aug. 22, 1982. Gaskets of this type generally have three essential features, a sealing bulb portion, a heel portion and an inner conical wall.
Since both the pipe bell and plain end may be produced without machining, relatively large variations in as-cast diameters are encountered. The gasket sealing bulb, in turn, is subjected to a wide range of compressions from approximately 2% to 45% of its original thickness. To aid in entry of the plain end into the gasketed bell over the large range of diameters encountered, the inner wall of the gasket is generally made in a conical form which tapers from the mating throat diameter of the bell to the inner sealing bulb diameter of the gasket. To further aid in the assembly, the gasket bulb has a relatively soft Shore A durometer hardness between about 40 and 60.
The retainer heel portion of the gasket is typically produced from a higher hardness compound than the sealing bulb to aid in retention of the gasket during joint assembly and to prevent blowout of the softer bulb portion when the assembled joint is subjected to high internal pressures. The retainer heel portion of a typical gasket has a Shore A durometer hardness between about 75 to 90. The retainer heel portion is generally designed to fit into a retaining groove of the bell section of the enclosing pipe. Known gaskets exhibiting these features are asymmetric in cross-sectional profile.
Gaskets of similar asymmetric cross-sectional profiles have also been produced from single hardness rubber compounds. If the entire gasket is of the harder compound, extremely high assembly forces are required. If the entire gasket is of the softer compound, the gasket is subject to be dislodged during assembly and, in addition, only relatively low internal pressures can be held. Single hardness gaskets are, therefore, normally produced of an intermediate Shore A hardness range from between about 60 and 75. In general, with single hardness gaskets of this type, one or more of the attributes of the dual hardness gasket is diminished.
It has been conventional to manufacture asymmetric profile annular pipe gaskets by the compression molding process. For dual hardness gaskets, a portion of the mold (corresponding to the retainer heel portion of the gasket) is filled with a rubber compound which, when cured, will have a Shore A durometer hardness of between about 75 and 90 and a second portion of the mold (corresponding to the sealing bulb portion of the gasket) is filled with a rubber compound which, when cured, will have a Shore A durometer hardness of between about 40 and 60. The mold is closed and, with suitable pressure and temperature, the two compounds are bonded together and the gasket is cured.
It is also conventional to manufacture asymmetric profile dual hardness gaskets by extruding the uncured compounds together to form a "preprep stock" of the desired profile cross-sectional area. The uncured preprep stock is then placed in a rubber mold for forming, joining and curing. Asymmetric profile dual hardness and single hardness gaskets are made by these and other well-known molding techniques.
SUMMARY OF THE INVENTION
The present invention relates to a method of making an asymmetric profile pipe gasket. The gasket is made by extruding a rubber compound in the shape of the cross section in a long extrusion, curing the extrusion, cutting the elongated extrusion a predetermined length and bonding the two free ends together to form an annular gasket.
Because the newly formed annular gasket has an asymmetric shape, unless special precautions are taken, the annular gasket will distort when rolled and bonded into a ring. This distortion makes the gasket unserviceable since the gasket would not properly sit in the pipe bell gasket retainer portion. This distortion will be more pronounced in those gaskets made with rubber material with two different hardnesses.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a method of making single or multiple hardness gaskets of asymmetric cross section comprising the steps of extruding through a die an extrusion made of rubber or similar elastomeric material, curing the strips, cutting the elongated strips a predetermined length and bonding the two free ends together to form an annular pipe gasket.
It is another object of the invention to provide a novel gasket of asymmetric cross section of single or multiple hardnesses which will not distort from the designed profile when an extruded length of the profile is rolled and bonded into a ring.
It is a further object of the present invention to provide a novel annular pipe gasket of asymmetric cross section having single or multiple hardnesses which is less expensive to produce than previously known gaskets.
BRIEF DESCRIPTION OF THE DRAWING
Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention taken in conjunction with the accompanying drawing in which like numerals indicate like elements and in which:
FIG. 1 is a cross-sectional view of a pipe bell using the gasket of the present invention and of a plain end of another pipe entering the pipe bell.
FIG. 2 is a cross-sectional view of a prior art pipe bell and gasket with a plain end of another pipe entering the pipe bell,
FIG. 3 is a cross-sectional view of a prior art gasket illustrating the distortion which occurs when the prior art gasket profile is extruded and spliced into a gasket,
FIG. 4 is a cross-sectional view of the gasket of the present invention showing the minor axis of flexure and the four quandrants of the gasket.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the preferred embodiment illustrated in FIG. 1 there is shown a joint which is to be formed between a pipe bell 1 of one pipe and a plain end 2 of another pipe. The gasket 3 of the present invention is shown in place in pipe bell 1.
The inner surface of pipe bell 1 has a retainer groove 4 bounded by a front wall 5 and retainer wall 6, and a compression rib 7 which extends radially inwardly from a sealing wall 8. In addition, the bell has a throat portion 9 which extends radially inwardly and joins the front wall 5. As the joint is assembled the throat 9 guides the plain end 2 until the bevelled end 10 contacts the conical inner face 11 of the gasket 3. The wedging action between the bevelled end 10 and the conical face 11 compresses the sealing bulb portion 12 of the gasket between the plain end 2 and the compression rib 7 and the sealing wall 8. The retainer wall 6 of the bell inner surface engages the retainer shoulder 13 of the gasket to prevent the gasket from dislodging during assembly of the joint.
In tight joint conditions, the gasket space G between the sealing wall 8 and plain end 2 is relatively small and the gasket compression and joint assembly forces are relatively high. A sealing bulb 12 of a relatively soft durometer elastomer is used to reduce the force required for tight joint assemblies. A harder durometer elastomer is used for the retainer heel portion 14 to prevent the gasket from dislodging during tight joint assemblies.
In loose joint conditions the throat gap T between the throat 9 and the plain end 2 is relatively large. When the pipe joint is pressurized, the gasket is forced toward the front wall 5 and fills the retainer groove 4 of the pipe bell. The softer sealing bulb 12 of the gasket will attempt to extrude through the throat gap T. The harder retainer heel portion 14 of the gasket, resists the extrusion of the softer bulb portion 12 of the gasket through the throat gap T.
While the invention has been described in the environment of a pipe joint in which the bell end of the enclosing pipe has a compression rib 7, the gasket will also perform its sealing function with a bell configuration such as that shown in U.S. Pat. No. 2,953,398 which does not have a compression rib.
The preferred embodiment gasket is made by forming an extrusion formed of two rubber compounds of different hardness. Each particular compound being extruded may be of an asymmetric cross section. Preferably, the two compounds are extruded through separate dies and immediately thereafter through a common die and subsequently cured in a manner well known to those skilled in the art of dual hardness rubber extrusion.
The cured dual hardness extrusion is then cut to a predetermined length having free ends. The two free ends are brought together and then spliced or adhered together to form a circular gasket. When an extrusion is bent to form a gasket, the profile of the extrusion has a natural tendency to bend about the weak or minor axis of flexure of the profile such that the minor axis of flexure forms a cylinder of revolution about the central axis of the gasket. In a homogeneous material in which the modulus of elasticity is the same in compression and in tension, the minor axis of flexure coincides with the minor axis of the moment of inertia of the profile. In rubber compounds, there can be considerable difference between the tensile modulus and the compressive modulus. This difference causes the minor axis of flexure to shift away from the minor axis of the moment of inertia. With symmetric profiles of rubber extrusions which have an axis of symmetry which coincides with the major axis of the moment of inertia (perpendicular to the minor axis), the axis of flexure is parallel to the minor axis of the moment of inertia. A parallel shift in the axes causes no distortion since both the axes form cylinders of rotation around the central axis of the gasket. Extrusions of symmetric profiles can, therefore, be readily formed into a ring without appreciable distortion of the profile.
It is well known that extruded straight strips of an elastomer can be cut a desired length and spliced to form an annular gasket. The known pipe gaskets made in this manner have a symmetrical cross-sectional profile with at least one axis of symmetry. Gaskets of this type are used for pipe which have diameters which vary over a relatively small range such as are encountered in machined joints.
It has been found that prior art asymmetric profile gaskets normally used for push-on joint pipe will distort from the intended profile when made by the extrusion process. The minor axis of flexure b-b' of the designed profile of a prior art gasket 17 of FIG. 2 is not parallel to the axis of rotation B-B'. As shown in FIG. 3 the prior art gasket 17 designed profile, if extruded and spliced into a ring, distorts from its intended shape so that the minor axis of flexure b-b' is cylindrical. In the distorted shape, the retainer shoulder 18 would form an angle to the bell retainer wall 19 and does not function to retain the gasket during assembly. In addition, the conical inner face 20 of gasket 17 distorts to be more cylindrical in shape. The distortions prevent gasket 17 from properly sitting in the pipe bell and functioning as a push-on joint pipe gasket over the required pipe tolerance ranges. Similar distortions occur with other known single and dual hardness asymmetric gasket profiles used for push-on joint pipe when the gaskets are made by the extrusion process.
It has been found that asymmetric profiles exhibiting the features required for push-on pipe gaskets can be designed such that the profiles will not distort when a single hardness rubber extrusions of the profiles are formed into an annular gasket. In addition, it has been found that asymmetric profiles exhibiting the features required for push-on pipe gaskets can be designed such that the profiles will not distort when multiple hardness extrusions of the profiles are formed into an annular gasket.
The minor axis of flexure a-a' of gasket 3 of FIG. 4 of the present invention is predetermined and calculated by first calculating the orientation of the minor axis of the moment of inertia of a proposed cross section. The proposed profile is divided into four basio quandrants C, D, E and F as shown in FIG. 4. Quadrants C and D form the harder retainer heel portion of the gasket while quandrants E and F form the softer sealing bulb portion of the gasket. Quadrants C and E are above the minor axis of the moment of inertia and are in a state of tensile stress when the extruded profile is formed into a ring gasket. Quadrants D and F are below the axis and are in a state of compressive stress when the extruded profile is formed into a ring gasket.
The orientation of the minor axis of flexure of the proposed cross section is obtained by transforming the cross section of different moduli into an equivalent cross section of a single modulus. This transformation is accomplished by making proportional mathematical increases in the area of each quadrant to the modulus of the quadrant. For example, if the moduli of quadrants C, D, E, and F are 1000, 2000, 3000 and 4000 psi respectively, the area of quadrant D is doubled, the area of quadrant E is tripled, the area of quadrant F is quadrupled and no change is made to the area of quadrant C. Tensile moduli are used for the quadrants above the minor axis and compressive moduli are used for the quadrants below the axis. A new minor axis of moment of inertia is then calculated for the transformed cross section. As a result, the minor axis of flexure divides the profile in such a manner that the tensile moduli on one side of said minor axis equals the compressive moduli on the other side of said minor axis. This minor axis is now a close approximation of the axis of flexure of the cross section if the moduli are linear over stress range encountered. In fact, the moduli of elastomers are normally not linear, but, over the relatively small stress levels required to bend the strip to form a gasket, a linear approximation adequately predicts the axis of flexure.
The desired orientation of the axis of flexure is obtained by making changes to the gasket contour 15 in nonessential sections of the profile and/or to the hard/soft parting line 16 and recalculating the orientation of the axis of flexure until the desired axis parallel to the central axis of the gasket is obtained. Nonessential sections of the profile are sections which do not breach the design of the conical inner face 11, the retainer shoulder 13 or the thickness of the sealing bulb.
The design process is aided by the use of computer graphics wherein the proposed gasket profile and hard/soft parting line is input to a graphics computer by digitizing the profile on a digitizing table. Computer software was developed to divide the profile into any desired finite number of small squares or rectangles. The moments of inertia are calculated for each square or rectangle using well-known moment of inertia equations. The moment of inertia and the orientation of the major and minor axes of the moment of inertia is then determined for the total shape using well-known equations. The proposed gasket profile with orientation of the axes is shown on the computer terminal. Changes are made to the gasket profile either on the computer screen or through the digitizing tablet and the resultant effects on the axis orientation are readily seen. Revisions are made to the profile until the required parallel minor axis is achieved. A similar technique can be used with single hardness gaskets or for gaskets with more than two hardnesses.
While the body of the specification primarily relates to the embodiment involving the extrusion of the gasket, the invention comtemplates the production of the same gasket via the use of a compression mold having the determined profile.
The present embodiments of this invention are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims.
|
This invention pertains to a method of making a pipe gasket having an asymmetric profile which is made by connecting two ends of an extruded elastomeric material, and the gasket made thereby.
| 8
|
This invention relates generally to aircraft propellers, and deals more particularly with an improved fixed pitch propeller designed to operate efficiently through a wide range of aircraft speeds.
BACKGROUND OF THE INVENTION
Prior art fixed pitch propellers can be designed to operate most efficiently either at climb speeds of the aircraft or below. In the alternative a conventional fixed pitch propeller can be designed to operate most efficiently at higher cruise speeds of the aircraft upon which they are installed. The purpose of the present invention is to provide an improved fixed pitch propeller which will operate efficiently in both regimes, and which will also exhibit improved performance of the aircraft upon which it is installed both at take off and at speeds in excess of cruise speed.
In aircraft equipped with conventional fixed pitch propellers the speed of rotation of the propeller is related to the throttle setting of the engine driving the propeller, and to the airspeed of the aircraft. A given propeller geometry will be most efficient at only one aircraft speed and at a particular engine speed. Variable pitch propellers that maintain a preset engine speed do overcome, and/or alleviate the inherent "single speed" design of conventional fixed pitch propellers. However, both fixed pitch propellers and variable pitch propellers are built on the premise that the relationship of blade pitch angle at a particular radial station of the blade is dictated primarily by the aircraft's forward speed, and engine speed, hence the station's blade rotational speed.
More specifically, fixed pitch propellers have traditionally been made with blade angles that are related to radial stations along the blade such that the trigonometric tangent of the blade angle (β) at a particular radial station is inversely proportional to the radial distance (R) of the station from the blade's rotational axis (tanβ= k R ). In a "cruise" prop this constant (k) is greater that it would be in a "climb" prop.
If we look at the helical path that the rotating propeller blade tip describes in space, for example, the "pitch distance" of the helix is a function of the propeller's speed, or more correctly velocity, and this velocity has a direction that is dictated by the rotational speed of the propeller and by the forward speed of the aircraft. The propeller is a rotating wing that generates lift (thrust) as it moves through the air. According to aerodynamic theory any wing has an optimum angle of attack that provides the highest ratio of lift (or thrust) to drag. Therefore, the propeller can only operate at optimum efficiency at a particular speed (corresponding to a particular forward speed and rotational speed). In a conventional fixed pitch propeller for example, the "pitch distance" of the ideal helix might be 72". This "pitch distance" is dictated by the blade angle at the tip, and this ideal helix also dictates blade angles at the various blade stations as described above. That is, tangent β= k R .
SUMMARY OF THE INVENTION
The new fixed pitch propeller described herein does not have a single constant (k) that dictates the blade angle along the entire blade's radius. Instead, the swept disc area defined by the propeller (excluding the relatively unusable hub area) is split (half and half) so that an outboard portion (from 60%-75% blade station to the tip) has a "climb" prop constant (n) that is less than the constant (k) referred to in the preceding paragraph. An inboard portion of the blade (from 20% to 60% or 75%) has a "cruise" prop constant (m) that is greater than the constant (k), and greater than the constant (n) that defines the blade angle of the outboard portion.
Traditional fixed pitch single "constant" propellers generally represents a compromise between a "climb" prop and a "cruise" prop. Such a compromise tends to overload the engine in the low aircraft speed regime due to the fact that the blade is operating at an angle of attack that is higher than the angle for best efficiency (maximum lift or thrust to drag). The result is low engine speed (RPM) at take off and hence reduced horsepower available (since horsepower is directly proportional to RPM).
The compromised or traditional fixed pitch single "constant" propeller also tends to overspeed at high aircraft speeds due to the fact that the blade is operating at an angle of attack that is too low for best efficiency (maximum thrust to drag for the airfoil shape used). The result is high engine speed (RPM) at the high speed end of the aircraft's performance envelope. In fact, excessive RPM's limit top speed because engine damage can result unless the pilot reduces aircraft speed and/or engine speed in this situation.
In further accordance with the present invention, and in addition to the above described blade angle relationships for the inner and outer blade portions, another approach to optimizing the blade performance over a wider range of aircraft speeds is disclosed. The airfoil geometry also has an influence on optimum blade efficiency (optimum thrust/drag). More specifically, a wider airfoil chord dimension can also effect the angle of attack for best efficiency. When combined with the above described blade angle relationships for the inner and outer blade portions this change to the airfoil geometry from blade root to tip can be so chosen as to further enhance the efficiency of this unique blade.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a prototype blade from the 20% radius or station to the 100% radius or tip station, and illustrates the blade profile with reference to the axis of rotation.
FIG. 2 is a tabular presentation of the specific dimensions depicted in FIG. 1.
FIG. 3 is a graphical presentation of the ratio of the power absorbed by a conventional fixed pitch propeller blade to that absorbed by the blade of FIGS. 1 and 2 (and assumes that all available brake horsepower is absorbed by the propeller at the speeds indicated at the left hand side of this view).
FIG. 4 is a graphical presentation of the relationship between the blade angle at various stations along the blade between the 20% and 100% radius of the blade.
FIG. 5 is a schematic graphical illustration of the variation in "twist" of the blade from the root end of the blade Ro to the tip of the blade Rt.
DETAILED DESCRIPTION
A typical fixed pitch propeller of conventional geometry is generally fabricated with a blade angle that varies from the root to the tip according to the relationship tangent of blade angle equals K R where the blade angle is measured relative to a radial plane and where k is a constant and R the radius of the particular station along the blade where the blade angle is to be calculated.
In order to improve the performance of a conventional fixed pitch propeller at relatively low speeds the constant K can be made less than would be the case if the propeller were primarily designed for use at cruise speed. In short, the manufacturer and/or his customer must decide whether he will opt for a fixed pitch propeller that is most efficient at climb speed or in the alternative to install a fixed pitch propeller which is most efficient at cruise speed. Alternatively, the prop may be a compromise between these two design configurations.
The present invention seeks to obviate this dilemma on the part of both the manufacturer and the aircraft owner in that a fixed pitch propeller is provided which will operate efficiently in both the climb speed regime and in the cruise speed regime.
The envelope of efficient operation for a fixed pitch prop according to the present invention is significantly expanded beyond that of a conventional fixed pitch propeller generally. Each propeller blade is provided with an inboard portion, extending generally from its 20% radius to its 60%-75% radius, with blade angles that are designed to permit efficient operation at cruise speeds or above. On the other hand from 65% to 100% radius the range of blade angles is so chosen that the propeller blade angles are most efficient at climb speeds. This combination not only provides for satisfactory operation in both speed regimes, but quite unexpectedly, also yields results that are significantly better than would be the case with conventional propeller blades of either climb or cruise speed configuration in both these speed regimes. FIG. 4 illustrates in graphic fashion the relationship between these inboard and outboard portions of a typical propeller blade.
Turning next to the specific example illustrated in FIGS. 1, 2 and 3 a propeller blade has been constructed in accordance with the present invention and actual tests have substantiated the theoretical results illustrated in FIG. 3. These results have been compared with a conventional fixed pitch propeller in FIG. 3. This comparison, though analytical in nature, is based upon the ability of the propeller to absorb engine power at various speeds. It should be observed that a conventional fixed pitch propeller will cause engine RPM to vary not only as a result of throttle setting but also as a result of aircraft speed. Therefore, at takeoff speed full RPM for the engine installation provided in a typical light aircraft may not be achieved until a speed far above takeoff speed with a conventional fixed pitch propeller. By the same token, at cruise speeds and higher the conventional fixed pitch propeller will create a situation where engine RPM can be excessive. In accordance with the present invention a propeller blade constructed as suggested in FIGS. 1, 2 and 3 will at take off and in climb have most of the engine horsepower absorbed by the outer blade portion from the 65% to the 100% radial station, and considerably less air will be drawn through the inboard portion of the blade due to the fact that the blade angles at the inboard stations are operating at angles of attack well above the angles associated with maximum efficiency. That is, the ratio of lift to drag (or propeller thrust to drag) will not be optimized in the inboard portion of the rotating propeller disc.
As speed increases, generally after the aircraft has climbed to its cruising altitude, the relative efficiency of the inboard portion of the propeller blade will be greatly improved. In fact, the outboard portion becomes totally inefficient and the outboard portion of the propeller blade will be unloaded in cruise even as the inboard portion of the blade was unloaded during takeoff and climb.
As a result of the unloaded portions of the blade being operated at zero angle of attack the engine power is totally available for the efficiently operating inboard "cruise" portion of the prop at higher cruise speeds. This result has the effect of permitting full throttle operation of the aircraft even at speeds well above cruise speed. Such a result has not been possible heretofore due to the fact that the engine speed would exceed the maximum recommended by the manufacturer if the aircraft were operated at high speed and at full throttle.
From FIG. 3 it will be apparent that the available brake horsepower will be more effectively utilized in a fixed pitch propeller constructed in accordance with the present invention, particularly at higher speeds. This has been substantiated by actual flight test, and the level flight cruising speed of a typical light airplane has been increased significantly when the airplane is equipped with a propeller constructed in accordance with the teachings of FIGS. 1 and 2.
From FIG. 4 it will be apparent that the preferred embodiment of the present invention provides a propeller blade having two different formulas to define the blade angle along its length. More specifically, an inboard blade portion from the 20 percent blade station to approximately the 60 percent blade station has a blade angle (β). The tangent of the blade angle (β) equals m divided by R where m is a constant somewhat greater than the constant generally used for present day fixed pitch propellers generally. From the tip of the propeller to the intermediate blade station referred to previously, the tangent of the blade angle (γ) is equal to a constant n divided by the radial distance to the particular station on the blade which is being calculated. This constant n is somewhat less than the typical constant normally provided in a conventional fixed pitch propeller generally. Preferably, the relationship between m and n is such that m is approximately 10 percent greater than n.
|
A fixed pitch propeller has blades that are not solely dependent on the blade angle dictated by the helical path of the blade tip. An outboard portion of the blade has a range of blade angles that are relatively flat to operate most efficiently at lower aircraft speeds. An inboard portion of the blade has a range of blade angles that are relatively high pitched to allow efficient operation at higher aircraft speeds
| 8
|
FIELD OF THE INVENTION
[0001] The invention relates to hydrolases obtainable from grains for use in food processing and manufacturing industries, to the germination of grains such as barley and to isolation of enzymes from grains.
BACKGROUND OF THE INVENTION
[0002] Many hydrolytic enzymes of grains, of which limit dextrinase (EC 3.2.1.142), α and β amylase (EC 3.2.1.1 and EC 3.2.1.2 respectively), 1-6-β-glucanase (EC 3.2.1.39), β1,4-xylanase (EC-3.2.1.8), arabinoxylanase (EC 3.2.1.136), and P glucosidase (EC 3.2.1.21) are examples, have found application in a variety of industries, and in particular, in food processing and manufacturing industries.
[0003] These enzymes, otherwise known as hydrolases, are typically obtained for commercial application from tissues such as plant tissue, including grains, pulses, legumes and the like and bacterial fermentations and the like. In some circumstances these enzymes may be produced in recombinant expression systems.
[0004] A problem with some of the processes by which many hydrolases are obtained for commercial application is that they tend to provide for a sub-optimal yield of hydrolase. Hence, considerable expense is incurred in obtaining commercial quantities of hydrolases.
[0005] There is a need for improvements in processes for obtaining hydrolases, especially improvements that are associated with improved yields of hydrolases.
SUMMARY OF THE INVENTION
[0006] In summary, in certain embodiments there is provided a process for increasing the amount of, or expression of an enzyme in a grain.
[0007] In other embodiments there is provided a process for producing a grain having a high relative abundance of an enzyme.
[0008] In other embodiments there is provided a process for producing an enzyme.
[0009] In further embodiment there is provided a process for extracting, purifying or isolating an enzyme for a grain having a high relative abundance of an enzyme.
[0010] Typically the process involves wounding a grain that is undergoing germination to form a wounded grain having at least one site of tissue damage that can be at least partially repaired by the wounded grain and permitting the wounded grain to at least partially repair an at least one site of tissue damage of the wounded grain to form a repaired grain. Otherwise stated, conditions are provided to a grain that provide for germination of a grain and that provide for one or more wounds to be applied to a grain. These conditions provide for a wound applied to a grain to be repaired by the grain.
[0011] In some embodiments the process includes allowing a rootlet to grow from a grain, removing the rootlet from the grain and growing a further rootlet from the grain.
[0012] In certain embodiments, a process for extracting, purifying or isolating an enzyme from a grain having a high relative abundance of an enzyme includes the further step of releasing or otherwise extracting and/or purifying or isolating an enzyme from a grain having a high relative abundance of an enzyme.
[0013] In further embodiments there is provided a grain having a high relative abundance of an enzyme. The grain is typically formed from a process involving providing conditions to a grain that provide for germination of the grain and for one or more wounds to be applied to the grain. These conditions also provide for a wound on a grain to be repaired by the grain.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0014] It has been found that the expression of hydrolases can be significantly increased, leading to a significant increase in the relative abundance or otherwise relative amount of a hydrolase in a tissue, in circumstances wherein a tissue is wounded and permitted to repair. Specifically, as described herein, it has been found that barley grains grown in conditions in which the grains were subjected to wounding and repair had amounts of hydrolases, α-amylase EC 3.2.1.1 and β-amylase EC 3.2.1.2, as much as 1.7 fold and 0.05 fold greater than barley grains grown in conditions not involving wounding and repair. Other hydrolases, limit dextrinase EC 3.2.1.142 and β1,4-xylanase EC 3.2.1.8 were found in up to 16.8 and 6.5 fold greater amounts in these grains.
[0015] These findings are particularly significant because when the grains the subject of injury and repair are processed for release of enzymes according to commercial extraction processes or otherwise, improved yields of hydrolytic enzymes can be obtained.
[0016] Thus in certain embodiments there is provided a process for increasing the amount of, or expression of an enzyme in a grain. The process includes the step of providing conditions to a grain that provide for germination of the grain and for one or more wounds to be applied to the grain, or in other words, for germinating a grain in conditions in which the grain is wounded by application of one or more wounds to the grain.
[0017] In other embodiments there is provided a process for producing a grain having a high relative abundance of an enzyme. The process includes the step of providing conditions to a grain that provide for germination of the grain and for one or more wounds to be applied to the grain.
[0018] In one embodiment, the grain is a barley grain. However, it will be understood that other grains may be processed, including, for example, rice, wheat, corm, maize and the like. Further, legumes and pulses such as lentils, soybeans and the like may also be processed.
[0019] It is important that the greater proportion of grains subjected to the process are not lethally wounded. A lethal wound tends to be one that results in death of a grain embryo, or one that otherwise prevents a grain from at least partially repairing a wound applied to the grain,—or otherwise from germinating.
[0020] Further, as discussed in more detail below, it has been found that a live grain embryo is associated with the enhanced secretion of one or more enzymes from a grain during germination.
[0021] The grain may be wounded by applying a physical treatment to the grain. Physical treatments include those that result in abrasion, laceration, tumbling, agitation or compression of the grain. Other forms of physical treatment are contemplated.
[0022] Particularly useful physical treatments are those that cause injury to a rootlet or part thereof such as a rootlet tip, or that remove a rootlet or part thereof from a grain, or an injury to a shoot, grain husk or pericarp. A treatment that results in an affect on an outer layer of a grain, aleurone layer or hemicellulose layer or like may also be useful.
[0023] An example of a process for abrasion of a grain is shown in U.S. Pat. No. 3,754,929. A process for compression of a grain is shown in U.S. Pat. No. 4,052,795.
[0024] Grain may also be wounded by one or more of chemical treatment, exposure to temperature, pressure or radiation.
[0025] Chemical treatments include alkali treatment. This treatment is particularly useful, among other things, for solubilizing or partially solubilizing the grain husk. An example of an alkali treatment is one wherein grains are conditioned over a time course of 24 hours during a second steep.
[0026] Other forms of chemical treatment include treatment with ammonia. An example of chemical treatment with ammonia is shown in U.S. Pat. No. 3,134,724.
[0027] As noted above, the grain may be wounded by heating the grain. Generally speaking, a grain should not be heated beyond 40° C. as above these temperatures, a grain embryo may be lethally wounded. Heating is generally performed during a second steep. Heating may be useful for softening a glucan outer husk of a grain.
[0028] A particularly useful wounding regimen is to apply a treatment to the grain that causes removal of a rootlet from the grain and in which repair mechanisms cause re-growth of a further rootlet from the wounded grain. In certain embodiments the rootlets are grown to about 5 to 7 days from the start of germination, although other time periods may be appropriate. Generally it is preferred to have removed rootlets before 12 days from the start of germination, and in some instances, earlier than this, for example, 10 days from the start of germination.
[0029] Although it is particularly useful to remove roots, rootlets, rot tips and shoots and shoot tips, in certain embodiments other grain organs may be removed, examples of which include grain husk and associated layers.
[0030] Generally speaking, roots, shoots or the like need only be removed once from a grain for there to be an enhancement in enzyme production beyond that observed iri unwounded grain. In certain embodiments, a treatment for wounding a grain is applied repeatedly. This has advantages for ensuring that all grains are wounded at least once, for example by removal of a root, shoot or the like once from each grain. This may be useful particularly as at any one time that a treatment is applied, not all grains may have reached the same stage of development of organ. Further in certain embodiments it is advantageous to remove more than one root, shoot or the like from a grain.
[0031] It will be understood that it is not necessary to re-injure a repaired grain. Further, it is not necessary that an injured grain undergo complete repair.
[0032] An example of an apparatus for applying a wound is shown in U.S. Pat. No. 3,174,909. Generally, an apparatus may be comprised of a drum for holding grains, the drum having an internal baffle, in use, for agitating grains contained in the drum when the drum is rolled, and a roller for rolling the drum.
[0033] Thus in certain embodiments there is provided a process for increasing the amount of a hydrolytic enzyme in a grain Including:
allowing a rootlet to grow from a grain; removing the rootlet from the grain; and allowing a further rootlet to grow from the grain, to increase the amount of a hydrolytic enzyme in a grain.
[0037] Germination is generally recognised as a process characterised by one or more of hydration of tissue leading to modulation of volume of a grain, modulation of enzyme activity, change in endosperm structure and composition and modulation of embryo activity.
[0038] Typically, the grains to which conditions for injury and repair are applied are grains that are undergoing germination i.e. grains that at the time of application of injury are about to germinate, or grains that are in an active state of germination at the time of application of injury, or grains that have completed germination at the time of application of injury.
[0039] In certain embodiments, the grains are in an active state of germination at the time of application of injury and remain in that state during repair and subsequent further injury and repair steps.
[0040] Typically, the grains have a moisture content of about 40% or less at the time that the injury and repair processes occur. The moisture content is a proportion of dry weight over hydrated weight. A moisture content of about 30-35% as a proportion of dry weight is particularly useful in certain embodiments.
[0041] Generally the moisture content is more than about 10%, more than about 15%, about 20%, about 25%, about 30% to 35% and generally should not exceed 40%.
[0042] In certain embodiments, the moisture content is more than about 25% after steeping and about 30% to 35% post an extended germination period and should not exceed 40% at any time.
[0043] The desired moisture content may be obtained by steeping the grains in an appropriate aqueous solution. The solution may simply be water, or it may include other compounds such as growth promoters, such as gibberillic acid, anti-microbials (such as SO 2 ) especially anti-fungals, or other compounds such as NH 4 OH alkalis to soften the grain and raise the pH.
[0044] The steep may consist of a single steeping step, or it may consist of multiple steeping steps, each step characterised according to the conditions applied during each steep. For example a first steep might include conditions in which grain is hydrated to less than about 40%. For example a grain may be hydrated from an initial grain moisture of ˜10% to about 20% moisture content in the presence of ˜50 ppm SO 2 for about 12-24 hours in the first steep. This solution may then be removed to exclude any bacteria and avoid any continued reaction with SO 2 on surface proteins or glucans. A second steep step might include adjusting hydration of the grain to about 20-30% moisture content at an increased pH up to 8.0, in the presence of 5-20 ppm gibberillic acid and perhaps some minor heating to 40° C. in the last hour for a total steeping time of 12-24 hours.
[0045] In certain embodiments, the grain is steeped for about 5 days, although it may be steeped for fewer days, for example, 1, 2, 3 or 4 days. Further, there may be benefit in steeping the grain for longer than 5 days. However, in these circumstances it becomes more difficult to control fungal contamination during the steeping process.
[0046] Further, a grain may be subjected to injury and/or repair prior to steeping, during steeping, or after steeping (i.e. at “steep out”).
[0047] It will be understood that in certain embodiments conventional steeping steps may not be required.
[0048] Where one or more steeping steps are implemented, the grain may be injured and permitted to repair for a period of up to 12 days after the completion of the steeping steps, although injury and repair may occur across a greater time. The length of time is dependent in part on the enzymes that are increased in the grain. Times that are suitable to specific grains are discussed further herein. In certain embodiments, the grain is injured and permitted to repair about 3 days after steeping is completed, about 5 days after steeping is completed or about 10 days after steeping is completed. During these times, the grain may be treated with a growth promoter such as gibberillic acid and maintained at less than 35% moisture in the presence of light.
[0049] In certain embodiments the conditions are controlled so as to minimise respiration of the grains during steeping or germination. Respiration is generally understood as a process by which energy is released from molecules such as carbohydrates. One advantage of limiting respiration is to minimise the extent of biochemical processes that are unrelated to wound repair, and hence conserve and direct available energy to wound repair, hence leading to increases in synthesis of a hydrolytic enzyme in a grain. Another advantage is to limit the production of molecules associated with respiration, such as sugars and CO 2 and the like which would support growth of contaminating microbes such as fungi and the like.
[0050] One way of minimising respiration is to control the moisture content of the grains undergoing germination and/or steeping. This can be achieved by controlling the relative humidity of the environment during germination and/or steeping, i.e. by controlling the temperature and moisture content of the environment. Generally it is preferable to provide conditions for minimising respiration which prevent starch granules in the grain from bursting. In one embodiment the relative humidity is about 80% and the temperature is less than about 20° C., preferably about 10 to 15° C.
[0051] In certain embodiments, the grain may be treated to eliminate microbes located on the surface of the grain. This may be useful for at least limiting contamination of the grain as the grain is undergoing germination. Particularly useful treatments are those that kill fungi, or fungal spores that would otherwise enable fungi to grow on grain during grain germination. Examples include washing in an anti-microbial, gassing in SO 2 or ammonia, treatment with urea, irradiation, especially UV irradiation, exposure to light.
[0052] An additional or alternative approach is to prevent root or shoot development from penetrating through the grain husk. In some circumstances, penetration of the husk by these organs provides opportunity for micro-organisms to infect the endosperm.
[0053] It will be understood that further enhancements in relative abundance of particular hydrolases in a grain can be obtained by modifying steeping conditions. Examples of modifications that are relevant to particular hydrolases are discussed further herein.
[0054] One particular advantage of the process discussed herein is that the grains obtained therefrom can be subjected to further downstream processing, such as for example to purify or otherwise extract enzymes from these grains. For example, the grains obtained from the process discussed herein could be subjected to the process discussed in U.S. Pat. No. 4,355,110 to purify pullulenase.
[0055] The process discussed herein is particularly useful for enhancing the expression of grain hydrolases, especially those located in the aleurone and starch endosperm layers, and embryo. Examples of enzymes include limit dextrinase, α and β amylase, 1-6-β-glucanase, β1,4-xylanase, arabinoxylanase, lipoxygenase and p glucosidase
[0056] α and β amylase may be obtained in enhanced amounts by a 2 day steep and 3 days germination.
[0057] Limit dextrinase may be obtained in enhanced amounts by a 2 day steep and 7-8 days germination.
[0058] Xylanase may be obtained in enhanced amounts by a 2 day steep and 10-12 days germination.
Example
[0059] Grains were steeped as described for 2 days and were then incubated for a further 10 to 15 days in conditions including:
[0000] UV illumination to retard microbial growth;
controlled temperature between about 7 and 13° C., normally about 10° C.;
controlled relative humidity at 80% with passive recirculating air flow;
periodic tumbling for 30 minute periods to prevent rootlets and shoots from penetrating the grain husk, each tumbling period followed by a 3 hour rest period.
|
The invention relates to a process for increasing the amount of enzymes in a grain by germinating the grain in conditions in which the grain is wounded. The invention also relates to hydrolases obtainable from grains for use in food processing and manufacturing industries, to the germination of grains such as barley and to isolation of enzymes from grains.
| 2
|
[0001] The present invention is a continuation-in-part of and claims priority to PCT WO 03/068999 published in English on 21 Aug. 2003 and to South African application 2002/0872, the entire contents of both are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to a heap bioleaching operation and more particularly is concerned with the delivery of a substance to a heap which is subjected to bioleaching.
[0003] The bioleaching of heaps of ores is a rapidly developing practice, particularly for the extraction of base metals from low grade sulphide ores. Through inoculation with bioleaching micro-organisms it is possible to initiate oxidation in ferrous- and sulphide-containing heaps which results in the liberation and solubilisation of base metals for subsequent solution recovery.
[0004] The effective extraction of metals in heap leaching operations depends, to a substantial extent, on the microbiological activity in the heaps. This activity is influenced by at least two factors, namely a uniform and effective distribution or inoculation of microbial cells capable of mineral leaching and an optimal nutrient availability to the microbial cells.
[0005] It is known to inoculate ore particles, substantially uniformly, by applying an inoculum to the particles prior to stacking the ore particles to form a heap, or by means of an agglomeration process. A more common method of inoculation is by irrigating a heap by recycling raffinate, a pregnant liquor solution or an intermediate liquor solution. The latter method is often resorted to due to the fact that a large volume of a suitable inoculum may not be available at the start of a heap leaching process, particularly during the stacking stage.
[0006] Nutrient compounds are required at certain optimal concentrations in order to facilitate microbial growth and activity. If these nutrients are added to an irrigation solution then they are likely to be precipitated from the solution as it migrates through a heap. This effectively removes the nutrients from the solution and the nutrients are then not available for microbial consumption.
[0007] The increased addition of nutrient compounds to an irrigation solution is undesirable due to the increased precipitation which would result from such addition. This, in turn, is detrimental to the chemical and physical factors which are desirable to facilitate the leaching process. If the nutrient compounds are precipitated then the microbial population in a heap is required to perform in a sub-nutrient environment and this results in sub-optimal bioleaching activity.
[0008] If a microbial inoculum is added to an irrigation solution, supplied for example to a top of a heap, then a sub-optimal distribution of the inoculum results due to the fact that the ore material through which the solution passes exerts attachment and filtration effects on the migrating microbial cells which give rise to a non-uniform microbial distribution within the heap.
SUMMARY
[0009] The invention provides a method of delivering a substance to a heap which is subjected to bioleaching which includes the steps of producing a gaseous suspension of particles of the substance and introducing the suspension into the heap.
[0010] The substance may include one or more nutrients of any suitable composition, a microbial inoculum, or any appropriate mixture of the aforegoing.
[0011] The nutrients may be selected from phosphates, ammonia, potassium and, more generally, nutrients which are known in the art as being desirable for promoting microbial activity within a heap leaching process. The invention is not limited in any way in this regard.
[0012] The microbial inoculum which is introduced into the heap is chosen according to requirement taking into account at least the following factors: the metal or metals which are to be leached; the ambient conditions, including temperature of the heap; the availability of nutrients; and similar parameters.
[0013] The inoculum may contain vegetative microbial cells but, preferably, use is made of ultra-micro bacteria (UMB). UMB are microbes which have been cultured in a manner which causes a reduction in size. As a consequence of such size reduction the carrying capacity of the gaseous suspension is increased.
[0014] It falls within the scope of the invention for the particles in the gaseous suspension to be solid but, preferably, the particles are in liquid form i.e. droplets.
[0015] The particle size should be below 20 micrometers and preferably is in the range of 5 to 10 micrometers.
[0016] The particles may be produced from a liquid suspension which contains the substance i.e. the nutrient or nutrients and the microbial cells.
[0017] The gaseous suspension of particles may be introduced into the heap using any appropriate technique and the invention is not limited in this regard. Preferably the suspension is injected into an air stream which is used to aerate the heap.
[0018] The invention may include the step of increasing the relative humidity of the air stream. The relative humidity of the air stream may be increased to a level which, given the circumstances, is as high as possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention is further described by way of example with reference to the accompanying drawings in which:
[0020] [0020]FIG. 1 schematically illustrates an aerosol generator for use in the method of the invention,
[0021] [0021]FIG. 2 schematically illustrates a technique for introducing an aerosol, produced in the manner shown in FIG. 1, into a heap which is subjected to a bioleaching process, and
[0022] [0022]FIG. 3 illustrates one possible interaction of aerosol droplets with ore particles within a heap.
DETAILED DESCRIPTION OF THE INVENTION
[0023] [0023]FIG. 1 of the accompanying drawings illustrates an aerosol generator 10 for use in the method of the invention. The function of the generator is to produce a gaseous suspension of fine liquid particles 12 from a liquid suspension 14 of a mixture of nutrients and microbial cells.
[0024] Without being limiting the nutrients in the suspension liquid 14 may include phosphates, ammonia and potassium.
[0025] The microbial cells in the suspension liquid 14 may be vegetative microbial cells but, as has been indicated, use is preferably made of ultra-micro bacteria (UMB). UMB are microbes which have been cultured in a manner which removes their polysaccharide cell envelopes, a process which often results in a reduction in size of the cells.
[0026] When a cell suspension is exposed to starvation conditions for a prolonged period changes occur in the cells in response to the unfavourable growth environment. The bacteria adapt through a series of starvation-survival responses with changes including a reduction in cell size, the use of cell storage products, a reduction in the endogenous respiration rate, a degradation of proteins, a reduction in RNA and the production of specific starvation proteins (Ref 1 ).
[0027] The starved cells are much smaller than the full-sized cells with significantly less glycocalyx (Ref 2 ; Ref 3 ). The small starved cells, which are usually termed ultra-micro bacteria, may be of the order of 0.3 micrometers or less in diameter. The UMB are dormant after starvation but they can be resuscitated with nutrient stimulation (Ref 3 ; Ref 4 ; Ref 5 ).
[0028] As a consequence of the size reduction and the reduced glycocalyx production the number of cells per unit volume which can be carried by each droplet is increased. It is also found that the maintenance requirements for the aerosol generator are reduced.
[0029] The aerosol generator 10 includes a vessel 16 which contains the liquid 14 and an outlet pipe 18 which has an inlet 20 below a level 22 of the liquid 14 . An air space 24 inside the vessel, above the liquid level 22 , is pressurised by any suitable device, not shown. This forces the liquid 14 upwardly through the pipe 18 , as is indicated by means of an arrow 26 , towards a baffle 28 which is in the nature of an atomising nozzle. As the liquid is forced through the baffle it is reduced to droplets in the range of 5 to 10 micrometers in diameter making up an aerosol 30 . FIG. 2 illustrates a heap 36 of ore particles, of any appropriate kind, which is subjected to a bioleaching process. The bioleaching process is not explained in detail herein for, generally, it is known in the art. The current explanation is confined to the method of delivering the liquid 14 , in droplet form, to the heap 36 .
[0030] An air manifold 38 extends through a lower region of the heap and has at least one and desirably a plurality of outlet nozzles 40 at different locations inside the heap.
[0031] The aerosol generator 10 , shown in FIG. 1, is connected to the manifold 38 at a location which is close to the heap 36 . The manifold is fed by an air blower 40 which produces a constant stream 42 of pressurised air which is passed into a humidifier 44 . The humidifier contains a counter-current water spray 46 which raises the relative humidity of the air to a level which is as high as possible under the circumstances. The humidified air leaves the humidifier through an exit 48 and the aerosol 30 is then injected into the air supply before the air passes into the manifold inside the heap.
[0032] The aerosol delivery system shown in FIG. 2 produces droplets which are sufficiently large to contain microbial cells but which are sufficiently small to be carried by the humidified air stream which is normally used for aerating the ore heap 36 . By injecting the aerosol into the air supply manifold the microbial cells and the nutrients are delivered to exposed surfaces of ore particles within the heap. This is effected without the adsorption and filtration effects, which have been referred to hereinbefore, impacting on this delivery mode.
[0033] The aerosol droplets are delivered in a gaseous suspension (the humidified air stream) and consequently the migration path of the droplets within the heap 36 is significantly less impeded than what is the case with liquid migration i.e. when the heap is irrigated from above with an appropriate solution. The aerosol droplets also penetrate the heap more rapidly. As the droplets are not in contact with mineral surfaces while in transit the risk of precipitation (in the case of nutrients) and of adsorption (in the case of microbial cells) is reduced. Greater uniformity of cell distribution and nutrient supplementation can therefore be achieved and maintained within the heap.
[0034] [0034]FIG. 3 illustrates one possible way in which the liquid 14 is applied to ore particles 50 within the heap 36 . A stream 52 of humidified air which contains droplets 30 is injected from one of the nozzles 40 (see FIG. 2) into the heap 36 . The air percolates upwardly along a myriad of paths between the particles 50 together with the entrained droplets 30 . The droplets break up upon colliding with ore particles 50 , as is indicated by means of reference numerals 54 , and the liquid in the droplets splutter-coats surfaces of the particles. This process results in an effective and wide-spread distribution of the inoculum and nutrients throughout the ore body within the heap. Clearly the degree of dispersion can be controlled, at least to a limited extent, by strategically positioning the air nozzles 40 of the manifold within the heap. To a considerable extent therefore it becomes possible to inoculate, or supply nutrients to, a heap, substantially uniformly, after the heap has been formed and, if necessary, on an on-going basis.
References
[0035] Ref 1 —Lappin-Scott, H. M. and Costerton, J. W. (1992). Ultramicrobacteria and their biotechnological applications. Curr Opinion Biotechnol 3, 283-285.
[0036] Ref 2 —MacLeod, F. A., Lappin-Scott, H. M. and Costerton, J. W. (1988). Plugging of a model rock system by using starved bacteria. Appl Environ Microbiol 54 6), 1365-1372.
[0037] Ref 3 —Lappin-Scott, H. M., Cusack, F., MacLeod, A. and Costerton, J. W. (1988b). Starvation and nutrient resuscitation of Klebsiella pneumoniae isolated from oil well waters. J Appl Bacteriol 64, 541-549.
[0038] Ref 4 —Lappin-Scott, H. M., Cusack, F. and Costerton, J. W. (1988a). Nutrient resuscitation and growth of starved cells in sandstone cores: A novel approach of enhanced oil recovery. Appl Environ Microbiol 54 (6), 1373-1382.
[0039] Ref 5 —Bryers, J. D. and Sanin, S. (1994). Resuscitation of starved ultramicrobacteria to improve in situ bioremediation. Annals New York Academy of Sciences . 745, 61-76.
|
A method of heap leaching wherein a gaseous suspension which contains a microbial inoculum or nutrients is introduced into the heap.
| 2
|
FIELD OF THE INVENTION
[0001] The present invention relates to direct memory access control generally and, more particularly, to a method and/or apparatus for implementing a multi-destination direct memory access transfer.
BACKGROUND OF THE INVENTION
[0002] Video processing, video coding, and graphics application technologies are markets that have been growing substantially over the last few years. The technologies are combined into many applications and are widely used. Video data bandwidth usage is high especially since video resolution enabled on televisions and personal computer monitors keep increasing all the time. For example, 1080 progressive (1080P) resolution is available now in most new televisions. An associated bandwidth for a simple display of 1080P video is about 3 gigabits per second. Digital signal processors performing video coding, video processing or graphics applications are sensitive to memory bandwidth criteria. The memory bandwidth criteria limit the performance of many systems rather than processing power. Therefore, memory bandwidth optimization is useful in order to enable such applications.
[0003] Many video processing techniques utilize several copies of a frame at several locations within a memory. Three-dimensional (3D) graphics applications also perform texture mapping over 3D scenes by considering the resolution from which to extract the current level of detail specified after a 3D warping. Furthermore, scalable Video Coding (SVC) uses multi-resolution representations of the video. The multi-resolution representations enable both error resilient transmission of the video and an ability to personalize video experience according to the edge device capabilities and type of service (i.e., standard or prime services).
[0004] Referring to FIG. 1 , a block diagram of a conventional method 10 for creating multi-destination copies is shown. In the method 10 , a frame stored at a location 12 is read directly from a memory 14 to two or more locations 16 a - 16 b in another memory 18 using two independent transfers 20 a - 20 b . The transfers 20 a - 20 b are controlled by a direct memory access engine 22 . A problem with the method 10 is that a bandwidth cost for the memory 14 is high, the total transfer is typically slow and a bottleneck is created for the application relying on the frames in the memory 18 . In the method 10 , the bandwidth involved is two frame reads from the memory 14 and two frames writes into the memory 18 .
[0005] Referring to FIG. 2 , a block diagram of another conventional method 30 for creating multi-destination copies is shown. In the method 30 , the frame at the location 12 is read from the memory 14 to the location 16 a using the transfer 20 a . The direct memory access engine 22 then copies the frame from the location 16 a to the location 16 b in another transfer 32 . The lack of the transfer 20 b decreases the bandwidth consumption of the memory 14 compared with the method 10 . However, method 30 still causes some issues. In particular, congestion is created in the memory 18 , especially if both copies of the frame in the memory 18 are to be accessed temporally proximate each other. A synchronization issue is also created due to the transfer 20 a writing to the location 16 a while the transfer 32 tries to read from the location 16 a . Furthermore, the internal memory bandwidth of the memory 18 is increased due to the added read from the location 16 a at the start of the transfer 32 .
SUMMARY OF THE INVENTION
[0006] The present invention concerns an apparatus generally including an internal memory and a direct memory access controller. The direct memory access controller may be configured to (i) read first information from an external memory across an external bus, (ii) generate second information by processing the first information, (iii) write the first information across an internal bus to a first location in the internal memory during a direct memory access transfer and (iv) write the second information across the internal bus to a second location in the internal memory during the direct memory access transfer. The second location may be different from the first location.
[0007] The objects, features and advantages of the present invention include providing a method and/or apparatus for implementing a multi-destination direct memory access transfer that may (i) read data from a source and store the data in several destinations, (ii) decimate the data before storing in one or more of the destinations, (iii) interpolate the data before storing in one or more of the destinations, (iv) filter the data before storing in one or more of the destinations, (v) reduce a bandwidth utilization of the source, (vi) maintain bandwidth utilization of the destinations, (vii) avoid congestion at the destinations, and/or (viii) free digital signal processing power from the task of making multiple copies of the data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other objects, features and advantages of the present invention will be apparent from the following detailed description and the appended claims and drawings in which:
[0009] FIG. 1 is a block diagram of a conventional method for creating multi-destination copies;
[0010] FIG. 2 is a block diagram of another conventional method for creating multi-destination copies;
[0011] FIG. 3 is a block diagram of an apparatus in accordance with a preferred embodiment of the present invention;
[0012] FIG. 4 is a functional flow diagram of an example method for a multi-destination transfer;
[0013] FIG. 5 is a functional block diagram of an example method for a processed, multi-destination transfer; and
[0014] FIG. 6 is a functional flow diagram of another example method for a multi-destination transfer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIG. 3 , a block diagram of an apparatus 100 is shown in accordance with a preferred embodiment of the present invention. The apparatus (or device or circuit) 100 generally comprises a circuit (or module) 102 , a circuit (or module) 104 , a circuit (or module) 106 , a circuit (or module) 107 , a circuit (or bus) 108 and a circuit (or bus) 110 . The circuits 102 to 110 may represent modules and/or blocks that may be implemented as hardware, firmware, software, a combination of hardware, firmware and/or software, or other implementations.
[0016] A signal (e.g., EXT) may be conveyed by the bus 108 between the circuit 102 and the circuit 104 . In some embodiments, the signal EXT may be a bidirectional signal. A signal (e.g., INT) may be conveyed by the bus 110 between the circuit 104 , the circuit 106 and the circuit 107 . In some embodiments, the signal INT may be a bidirectional signal. A signal (e.g., TASK) may be presented from the circuit 107 to the circuit 104 .
[0017] The circuit 102 may be fabricated in (on) a die (or chip) 112 . In some embodiments, the circuits 104 , 106 , 107 and 110 may be fabricated in (on) another die (or chip) 114 . In other embodiments, all of the circuits 102 - 110 may be fabricated in (on) the same die (e.g., 112 or 114 ).
[0018] The circuit 102 may implement an external memory circuit. The circuit 102 is generally operational to store data presented to and received from the circuit 104 via the signal EXT on the bus 108 . In some embodiments, the circuit 102 may be implemented as a double data rate (DDR) memory. Other memory technologies may be implemented to meet the criteria of a particular application. Since the circuit 102 may be fabricated on the die 112 apart from the die 114 , the circuit 102 may be considered external to the circuits of the die 114 .
[0019] The circuit 104 may be implemented as a Direct Memory Access (DMA) controller circuit. The circuit 104 may be operational to transfer the data between the circuit 102 and the circuit 106 in one or more DMA transfer operations. Some transfers may be from a single location in a source circuit (e.g., 102 ) to a single location in a destination circuit (e.g., 106 ). Other transfers may be from a single location in the source circuit to two or more locations in the destination circuit.
[0020] Where a DMA transfer involves multiple destinations, the circuit 104 may be further operational to process the data routed to at least one of the locations in the destination circuit. Processing may include, but is not limited to, decimation, interpolation, filtering and/or deinterlacing of the data. For example, where the data is an image, picture, frame or field from a video sequence or still picture, the decimation may include removal of every other pixel horizontally and/or vertically. Other decimation techniques may be implemented to meet the criteria of a particular application. As a result, an image may be copied from the circuit 102 to a given location in the circuit 106 at full resolution while another smaller version of the image may be written to another location in the circuit 106 .
[0021] Where the processing is an interpolation, multiple copies of an image may be copied from the circuit 102 to multiple locations in the circuit 106 . Each copy in the circuit 106 may have a different size (or resolution). For example, a standard video frame (e.g., 720 by 480 pixels) may be copied from the circuit 102 to a particular location in the circuit 106 without interpolation. Another copy of the standard video frame may be interpolated to a high resolution (e.g., 1920 by 1080 pixels) and stored at a different location in the circuit 106 . Furthermore, the processing may include conversion of the interlaced fields into progressive frames. Therefore, the circuit 106 may contain both standard and high-definition frames that are eventually presented to a standard and/or high-definition displays and/or recording devices.
[0022] Where the process is filtering, a lowpass filter may be implemented to smooth the data (e.g., smooth an image of a still picture or field/frame of video. The lowpass filtering may also be designed to decimate pictures/fields/frames. High-pass filtering may also be implemented to sharpen details in the pictures/fields/frames. Other types of filtering may be implemented to meet the criteria of a particular application.
[0023] The circuit 106 may implement one or more internal memory circuits. The circuit 106 is generally operational to store one or more copies of the data received from and/or present data to the circuit 104 in the signal INT. In some embodiments, the circuit 106 my implement a static random access memory. In other embodiments, the circuit 106 may implement a dynamic random access memory. Other memory technologies may be implemented to meet the criteria of a particular application. Since the circuit 106 may be fabricated on the same die 114 as the circuit 104 , the circuit 106 may be considered an internal memory.
[0024] The circuit 107 may implement a Digital Signal Processor (DSP) circuit. The circuit 107 is generally operational to process the data stored in the circuit 106 . The processing may include, but is not limited to video processing, graphics processing, audio processing and still picture processing. Access to the circuit 106 may be via bus 110 . The circuit 107 may also be operational to configure the circuit 104 to perform one or more DMA transfer operations. Configuring may be achieved by loading a source address and one or more destination addresses into the circuit 104 via the signal TASK.
[0025] The circuit 108 may implement an external memory bus circuit. The circuit 108 is generally operational to achieve control of the circuit 102 and transfer data to and from the circuit 102 . Where the circuit 102 is fabricated on a die separate from the circuit 104 , line drivers, electrostatic discharge circuitry, termination circuitry and the like may be implemented for the circuit 108 . In some embodiments, the circuit 108 is a point-to-point bus to connect to a single circuit 102 . In other embodiments, the circuit 108 may implement a multi-drop bus to connect to multiple circuits 102 . Other inter-chip bus technologies may be implemented to meet the criteria of a particular application.
[0026] The circuit 110 may implement an internal memory bus circuit. The circuit 110 is generally operational to exchange data between the circuit 104 and the circuit 106 and between the circuit 106 and the circuit 107 . In some embodiments, the circuit 110 may be a multi-drop bus. Other intra-chip bus technologies may be implemented to meet the criteria of a particular application.
[0027] Referring to FIG. 4 , a functional flow diagram of an example method 120 for a multi-destination transfer is shown. The method (or process) 120 generally comprises a step (or operation) 122 , a step (or operation) 124 , a step (or operation) 126 , a step (or operation) 128 , a step (or operation) 130 and a step (or operation) 132 . The steps 122 to 132 may represent modules and/or blocks that may be implemented as hardware, firmware, software, a combination of hardware, firmware and/or software, or other implementations. The method 120 may be performed by the apparatus 100 .
[0028] In the step 122 , data (e.g., a frame) may be stored in the circuit 102 . The data may be transferred (e.g., read) from the circuit 102 to the circuit 104 in the step 124 . The transfer may take place on the bus 108 . Step 124 may form a part of a single DMA transfer operation. In the step 126 , the circuit 104 may transfer (e.g., write) the data to the circuit 106 via the bus 110 . The circuit 106 may store the data in the step 128 at a given location. The transfer of step 126 and storage of step 128 may also form parts of the single DMA transfer operation. The data may undergo another transfer (e.g., write) from the circuit 104 to the circuit 106 in the step 130 . The transfer of step 130 may also take place on the bus 110 . In the step 132 , the data may be stored in the circuit 106 at another location. The transfer of step 130 and the storage of step 132 may form parts of the single DMA transfer. Steps 130 and 132 may be performed in parallel to steps 126 and 128 . Although the method 120 illustrates two destinations for the data in the circuit 106 , other embodiments may write the data to three or more destinations using the same technique.
[0029] Referring to FIG. 5 , a functional block diagram of an example method 140 for a processed, multi-destination transfer is shown. The method (or process) 140 generally comprises the step 122 , the step 124 , the step 126 , the step 128 , a step (or operation) 142 , a step (or operation) 144 and a step (or operation) 146 . The steps 122 to 146 may represent modules and/or blocks that may be implemented as hardware, firmware, software, a combination of hardware, firmware and/or software, or other implementations. The method 140 may be performed by the apparatus 100 .
[0030] The steps 122 to 128 in the method 140 may be the same as in the method 120 . In the step 122 , data (e.g., a frame) may be stored in the circuit 102 . The data may be transferred (e.g., read) from the circuit 102 to the circuit 104 in the step 124 . The transfer may take place on the bus 108 . Step 124 may form a part of a single DMA transfer operation. In the step 126 , the circuit 104 may transfer (e.g., write) the data to the circuit 106 via the bus 110 . The circuit 106 may store the data in the step 128 at a given location. The transfer of step 126 and storage of step 128 may also form parts of the single DMA transfer operation.
[0031] In the step 142 , the circuit 104 may process the data as received from the circuit 102 . The processing may include, but is not limited to, decimating, interpolating, filtering and/or deinterlacing. Step 142 may be performed in parallel to steps 126 and 128 . In the step 144 , the processed data may be transferred from the circuit 104 to the circuit 106 via the bus 110 . The circuit 106 may store the processed data in the step 146 at another location, different from the location used in the step 128 . Although the method 140 illustrates two destinations for the data in the circuit 106 , other embodiments may write the data to three or more destinations using the same technique.
[0032] As illustrated in the methods 120 and 140 , the circuit 100 generally has a capability to receive and operate on a source location and several destination locations. Writing to the several destination locations may be performed using one or more transfer techniques, depending on the capabilities of the circuit 106 . The transfer techniques may include, but are not limited to, sequential, parallel, interleaved and/or alternating transfers. For example, where the circuit 106 has a single data port, the circuit 104 may perform multiple sequential transfers through the data port to write the data to multiple locations (or addresses). Where the circuit 106 is implemented as a multiport device, the circuit 104 may transfer multi-destination data in parallel to respective multiple ports. The data may be multiple copies of the same data or a copy of the data and a copy of processed data. In either situation, a frame or other block of data may be read once from a single location in the circuit 102 and written into the circuit 106 at multiple locations. Thus, the bandwidth utilized on the bus 108 and the circuit 102 may be a single read operation. The bandwidth utilized on the bus 110 and the circuit 106 may be N writes, where N is the number of copies written into the circuit 106 .
[0033] Furthermore, the apparatus 100 generally avoids the congestion issue and the synchronization issue described for FIG. 2 . In particular, the writes (e.g., step 128 and 132 ) of the data into multiple different areas of the circuit 106 may be performed independently of each other. Furthermore, the write of step 128 into an area of the circuit 106 does not have to be synchronized with a subsequent read from the same area.
[0034] Improvements in performance may be created by the processing step 142 of the method 140 . By processing the data before writing to the circuit 106 , the method 140 generally avoids a subsequent read and a subsequent write to the circuit 106 . For example, without the step 142 , data written unprocessed to an area of the circuit 106 may be subsequently read from the circuit 106 , processed elsewhere (e.g., the circuit 107 ) and then written back into the circuit 106 . Processing elsewhere uses additional bandwidth necessitated by the pre-processing read from the circuit 106 and the post-processing write to the circuit 106 . Buffering the unprocessed data in the circuit 106 may also increase the utilized storage capacity of the circuit 106 . For example, where the processing is a decimation of the frame, two full frames may be initially stored in the circuit 106 . After decimation of a frame copy by half both vertically and horizontally, a quarter-sized frame may be written back into the circuit 106 . Therefore, the circuit 106 should be sized to handle the two full frames plus the quarter-size frame. Using the method 140 , the data is processed (e.g., decimated) before the initial write into the circuit 106 . Therefore, the circuit 106 may be sized to store a full frame and the smaller quarter-sized frame, a savings of three-quarters of a frame. Method 140 may also save processing power of the circuit 107 . By performing the initial processing in the circuit 106 , the processed data may be readily available to the circuit 107 in a more suitable form.
[0035] Referring to FIG. 6 , a functional flow diagram of an example method 160 for a multi-destination transfer is shown. The method (or process) 160 generally comprises a step (or operation) 162 , a step (or operation) 164 , a step (or operation) 166 , a step (or operation) 168 , a step (or operation) 170 , a step (or operation) 172 and a step (or operation) 174 . The steps 162 to 174 may represent modules and/or blocks that may be implemented as hardware, firmware, software, a combination of hardware, firmware and/or software, or other implementations. The method 160 may be performed by the apparatus 100 .
[0036] In the step 162 , data may be stored in the circuit 106 . The data may be transferred (e.g., read) from the circuit 106 to the circuit 104 in the step 164 . The transfer may take place on the bus 110 . Step 164 may form a part of a single DMA transfer operation. In the step 166 , the circuit 104 may transfer (e.g., write) the data to the circuit 102 via the bus 108 . The circuit 102 may store the data in the step 168 at a given location. The transfer of step 166 and storage of step 168 may also form parts of the single DMA transfer operation. Within the circuit 104 , the data may undergo optional processing in the step 170 . The processed data may be transferred (e.g., write) from the circuit 104 to the circuit 102 in the step 172 . The transfer of step 172 may also take place on the bus 108 . In the step 174 , the data may be stored in the circuit 102 at another location. The transfer of step 172 and the storage of step 174 may form parts of the single DMA transfer. Although the method 160 illustrates two destinations for the data in the circuit 102 , other embodiments may write the data to three or more destinations using the same technique.
[0037] The architecture of the apparatus 100 generally improves memory bandwidth utilization problems commonly found in video processing, 3D graphics and other high memory bandwidth applications. The methods 120 , 140 and/or 160 generally result in better bandwidth utilization of the circuit 102 , the circuit 106 , the bus 108 and the bus 110 than existing methods. The methods 120 , 140 and/or 160 generally do not suffer from the congestion problem and synchronization problem associated with the method 30 . Establishing multiple resolution versions of a frame in the circuit 106 as part of a single DMA transfer operation has an advantage. For example, the creation of downscaled versions of the frame saves the circuit 107 from reading from the circuit 106 , performing the downscaling operation and writing back to the circuit 106 .
[0038] The methods 120 , 140 and/or 160 generally enable efficient memory copying operations for video, graphics and other applications, in which the same content is copied from the source circuit to multiple locations in the destination circuit and/or at multiple resolutions. The multi-resolution and/or multi-location copy operations may be performed by a circuit 104 having a design optimized for the particular application(s).
[0039] The apparatus 100 generally reads data from a source and stores the data into several destinations. Decimation, interpolation, filtering, deinterlacing and/or other processing techniques may be applied to one or more of the copies during the DMA transfer operation. Therefore, the apparatus 100 generally lowers the bandwidth utilization of both the circuits 102 and 106 , does not suffer from the congestion problems or the synchronization problems. The apparatus 100 may also free the circuit 107 to perform other useful tasks by performing initial processing of one or more of the copies.
[0040] The functions performed by the diagrams of FIGS. 4-6 may be implemented using one or more of a conventional general purpose processor, digital computer, microprocessor, microcontroller, RISC (reduced instruction set computer) processor, CISC (complex instruction set computer) processor, SIMD (single instruction multiple data) processor, signal processor, central processing unit (CPU), arithmetic logic unit (ALU), video digital signal processor (VDSP) and/or similar computational machines, programmed according to the teachings of the present specification, as will be apparent to those skilled in the relevant art(s). Appropriate software, firmware, coding, routines, instructions, opcodes, microcode, and/or program modules may readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant art(s). The software is generally executed from a medium or several media by one or more of the processors of the machine implementation.
[0041] The present invention may also be implemented by the preparation of ASICs (application specific integrated circuits), Platform ASICs, FPGAs (field programmable gate arrays), PLDs (programmable logic devices), CPLDs (complex programmable logic device), sea-of-gates, RFICs (radio frequency integrated circuits), ASSPs (application specific standard products), one or more monolithic integrated circuits, one or more chips or die arranged as flip-chip modules and/or multi-chip modules or by interconnecting an appropriate network of conventional component circuits, as is described herein, modifications of which will be readily apparent to those skilled in the art(s).
[0042] The present invention thus may also include a computer product which may be a storage medium or media and/or a transmission medium or media including instructions which may be used to program a machine to perform one or more processes or methods in accordance with the present invention. Execution of instructions contained in the computer product by the machine, along with operations of surrounding circuitry, may transform input data into one or more files on the storage medium and/or one or more output signals representative of a physical object or substance, such as an audio and/or visual depiction. The storage medium may include, but is not limited to, any type of disk including floppy disk, hard drive, magnetic disk, optical disk, CD-ROM, DVD and magneto-optical disks and circuits such as ROMs (read-only memories), RAMS (random access memories), EPROMs (electronically programmable ROMs), EEPROMs (electronically erasable ROMs), UVPROM (ultra-violet erasable ROMs), Flash memory, magnetic cards, optical cards, and/or any type of media suitable for storing electronic instructions.
[0043] The elements of the invention may form part or all of one or more devices, units, components, systems, machines and/or apparatuses. The devices may include, but are not limited to, servers, workstations, storage array controllers, storage systems, personal computers, laptop computers, notebook computers, palm computers, personal digital assistants, portable electronic devices, battery powered devices, set-top boxes, encoders, decoders, transcoders, compressors, decompressors, pre-processors, post-processors, transmitters, receivers, transceivers, cipher circuits, cellular telephones, digital cameras, positioning and/or navigation systems, medical equipment, heads-up displays, wireless devices, audio recording, storage and/or playback devices, video recording, storage and/or playback devices, game platforms, peripherals and/or multi-chip modules. Those skilled in the relevant art(s) would understand that the elements of the invention may be implemented in other types of devices to meet the criteria of a particular application.
[0044] As would be apparent to those skilled in the relevant art(s), the signals illustrated in FIGS. 3-6 represent logical data flows. The logical data flows are generally representative of physical data transferred between the respective blocks by, for example, address, data, and control signals and/or busses. The system represented by the circuit 100 may be implemented in hardware, software or a combination of hardware and software according to the teachings of the present disclosure, as would be apparent to those skilled in the relevant art(s).
[0045] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the scope of the invention.
|
An apparatus generally including an internal memory and a direct memory access controller is disclosed. The direct memory access controller may be configured to (i) read first information from an external memory across an external bus, (ii) generate second information by processing the first information, (iii) write the first information across an internal bus to a first location in the internal memory during a direct memory access transfer and (iv) write the second information across the internal bus to a second location in the internal memory during the direct memory access transfer. The second location may be different from the first location.
| 8
|
CROSS-REFERENCE TO RELATED APPLICATIONS
The present disclosure is a continuation of U.S. application Ser. No. 12/842,452 (now U.S. Pat. No. 7,957,094), filed on Jul. 23, 2010, which is a divisional of U.S. application Ser. No. 11/495,295 (now U.S. Pat. No. 7,764,462), filed Jul. 28, 2006, which claims priority under 35 U.S.C §119(e) to U.S. Provisional Application No. 60/759,164, filed Jan. 13, 2006.
FIELD
The present disclosure relates to hard disk drives (HDD).
BACKGROUND
Electronic devices such as computers, laptops, personal video recorders (PVRs), MP3 players, game consoles, set-first boxes, digital cameras, and other electronic devices often need to store a large amount of data. Storage devices such as hard disk drives (HDDs) and digital versatile discs (DVDs) may be used to meet these storage requirements. As the size of these devices decreases, heat dissipation has become more problematic.
Referring now to FIG. 1A , hard disk drive (HDD) 10 includes a hard drive assembly (HDA) printed circuit board assembly (PCBA) 14 . A buffer module 18 stores data that is associated with control of the HDD 10 . The buffer module 18 may employ SDRAM or other types of low latency memory. A processor 22 that is arranged on the HDA PCBA 14 performs processing that is related to the operation of the HDD 10 . A hard disk control module (HDC) 26 communicates with an input/output interface 24 and with a spindle/voice coil motor (VCM) driver module 30 and/or a read/write channel module 34 .
During write operation, read/write channel module 34 encodes the data to be written via a read/write device 59 , as described in detail hereinbelow. The read/write channel module 34 processes the signal for reliability and may include, for example, error correction coding (ECC), run length limited coding (RLL), and the like. During read operation, the read/write channel module 34 converts an analog output of the read/write device 59 to a digital signal. The converted signal is then detected and decoded by known techniques to recover the data written on the HDD.
As can be appreciated, one or more of the functional blocks of the HDA PCBA 14 may be implemented by a single integrated circuit (IC) or chip. For example, a first integrated circuit 1 C- 1 may include the buffer module 18 and the processor 22 . A second integrated circuit 1 C- 2 may implement the HDC module 26 , the spindle VCM module 30 , the read write channel module 34 and/or the I/O interface 24 . Still other component combinations may be implemented as integrated circuit(s). For example, the processor 22 and the HDC module 26 may be implemented by a single integrated circuit. The spindle/VCM driver module 30 and/or the read/write channel module 34 may also be implemented by the same integrated circuit as the processor 22 and/or the HDC module 26 .
A hard drive assembly (HDA) case 50 provides a housing for one or more hard drive platters 52 , which include a magnetic coating that stores magnetic fields. The platters 52 are rotated by a spindle motor 54 . Generally the spindle motor 54 rotates the hard drive platter 52 at a fixed speed during the read/write operations. One or more read/write arms 58 move relative to the platters 52 to read and/or write data to/from the hard drive platters 52 . The spindle/VCM driver module 30 controls the spindle motor 54 , which rotates the platter 52 . The spindle/VCM driver module 30 also generates control signals that position the read/write arm 58 , for example using a voice coil actuator, a stepper motor or any other suitable actuator.
The read/write device 59 is located near a distal end of the read/write arm 58 . The read/write device 59 includes a write element such as an inductor that generates a magnetic field. The read/write device 59 also includes a read element (such as a magneto-resistive (MR) element) that senses the magnetic field on the platter 52 . A preamp module 60 amplifies analog read/write signals. When reading data, the preamp module 60 amplifies low level signals from the read element and outputs the amplified signal to the read/write channel device. While writing data, a write current is generated which flows through the write element of the read/write device 59 is switched to produce a magnetic field having a positive or negative polarity. The positive or negative polarity is stored by the hard drive platter 52 and is used to represent data.
Referring now to FIG. 1B , an exemplary DVD system 61 . A DVD PCBA 62 includes a buffer 64 that stores read data, write data and/or volatile control code that is associated the control of the DVD system 61 . The buffer 64 may employ volatile memory such as SDRAM or other types of low latency memory. Nonvolatile memory 66 such as flash memory can also be used for critical data such as data relating to DVD write formats and/or other nonvolatile control code. A processor 68 arranged on the DVD PCBA 62 performs data and/or control processing that is related to the operation of the DVD system 61 . The processor 68 also performs decoding of copy protection and/or compression/decompression as needed. A DVD control module 70 communicates with an input/output interface 72 and with a spindle/feed motor (FM) driver 74 and/or a read/write channel module 76 . The DVD control module 70 coordinates control of the spindle/FM driver 74 , the read/write channel module 76 and the processor 68 and data input/output via the interface 72 .
During write operations, the read/write channel module 76 encodes the data to be written by an optical read/write (ORW) or optical read only (OR) device 78 to the DVD platter. The read/write channel module 76 processes the signals for reliability and may apply, for example, ECC, RLL, and the like. During read operations, the read/write channel module 76 converts an analog output of the ORW or OR device 78 to a digital signal. The converted signal is then detected and decoded by known techniques to recover the data that was written on the DVD.
A DVD assembly (DVDA) 82 includes a DVD medium 84 that stores data optically. The medium 84 is rotated by a spindle motor that is schematically shown at 86 . The spindle motor 86 rotates the DVD medium 84 at a controlled and/or variable speed during the read/write operations. The ORW or OR device 78 moves relative to the DVD medium 84 to read and/or write data to/from the DVD medium 84 . The ORW or OR device 78 typically includes a laser and an optical sensor.
For DVD read/write and DVD read only systems, the laser is directed at tracks on the DVD that contain lands and pits during read operations. The optical sensor senses reflections caused by the lands/pits. In some DVD read/write (RW) applications, a laser may also be used to heat a die layer on the DVD platter during write operations. If the die is heated to one temperature, the die is transparent and represents one binary digital value. If the die is heated to another temperature, the die is opaque and represents the other binary digital value. Other techniques for writing DVDs may be employed.
The spindle/FM driver 74 controls the spindle motor 80 , which controllably rotates the DVD medium 84 . The spindle/FM driver 74 also generates control signals that position the feed motor 90 , for example using a voice coil actuator, a stepper motor or any other suitable actuator. The feed motor 90 typically moves the ORW or OR device 78 radially relative to the DVD medium 84 . A laser driver 92 generates a laser drive signal based on an output of the read/write channel module 76 . The DVDA 82 includes a preamp circuit 93 that amplifies analog read signals. When reading data, the preamp circuit 93 amplifies low level signals from the ORW or OR device and outputs the amplified signal to the read/write channel module device 76 .
The DVD system 61 may further include a codec module 94 that encodes and/or decodes video such as any of the MPEG formats. A scrambler 97 may be used to perform data scrambling. Audio and/or video digital signal processors and/or modules 96 and 95 , respectively, perform audio and/or video signal processing, respectively.
SUMMARY
A drive system including: a printed circuit board; a first integrated circuit mounted onto the printed circuit board; a drive assembly case that is connected to the printed circuit board; and a first thermal interface material thermally coupled between i) the printed circuit board and ii) the drive assembly case. Thermal energy generated by the first integrated circuit is dissipatable by the drive assembly case through the first interface material.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1A is a functional block diagram of an exemplary hard disk drive according to the prior art;
FIG. 1B is a functional block diagram of an exemplary digital versatile disc (DVD) according to the prior art;
FIG. 2A illustrates a first drive system that is thermally coupled to a drive assembly case according to the present disclosure;
FIG. 2B illustrates the first drive system with an integrated circuit in direct physical contact with the drive assembly case;
FIG. 3 illustrates a second drive system that is thermally coupled to a drive assembly case according to the present disclosure;
FIG. 4 illustrates a third drive system that is thermally coupled to a drive assembly case according to the present disclosure;
FIG. 5 illustrates a fourth drive system that is thermally coupled to a drive assembly case according to the present disclosure;
FIG. 6A is a functional block diagram of a high definition television;
FIG. 6B is a functional block diagram of a vehicle control system;
FIG. 6C is a functional block diagram of a cellular phone;
FIG. 6D is a functional block diagram of a set top box; and
FIG. 6E is a functional block diagram of a media player.
DETAILED DESCRIPTION
The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the term module, circuit and/or device refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
The present disclosure relates to a low cost thermal solution for dissipating heat when high power integrated circuits (ICs) are used in drive systems. For example, the present invention may be used in hard disk drive (HDD) and digital versatile disc (DVD) systems. The HDD includes a hard disk assembly (HDA) and a HDD printed circuit board assembly (HDD PCBA) with one or more Integrated Circuits (ICs) and/or other electronics components mounted thereon. Some types of HDDs include an external case that is connected to the HDD PCB. While the certain portions of the present disclosure relate to HDD systems, the present disclosure can also be used to dissipate heat within DVD systems.
The ICs tend to generate a lot of heat due to high data flow speeds of the HDD or DVD and integration of more functions and features. As the form factor of the HDD or DVD becomes smaller, the PCB also becomes smaller. Dissipating heat generated by the IC or ICs of the PCB becomes more challenging. According to the present disclosure, the drive assembly case can be used as a thermal heatsink by making the surface of one or more ICs directly contact the drive assembly case and/or using a thermal interface material to allow the thermal contact between the IC or ICs and the drive assembly case.
Referring now to FIGS. 2A and 2B , the drive assembly case can be used as a thermal heatsink by making the printed circuit board (PCB) contact the drive assembly case through a thermal interface material. More particularly, in FIG. 2A a PCB 100 includes an outer side 101 and an inner side 102 . First and second integrated circuits (ICs) 104 and 108 and/or other components 112 are mounted on the outer and/or inner sides 101 and 102 of the PCB 100 .
A drive assembly case 118 is connected to the inner side 102 of the PCB 100 . A second side of the IC 108 includes a thermal interface material 120 that is located between the IC 108 and the drive assembly case 118 . The terminal interface material 120 thermally couples the second side of the IC 108 to the drive assembly case 118 . As a result, heat generated by the IC 108 is dissipated by the relatively large surface area of the drive assembly case 118 . In FIG. 2B , the IC 108 directly contacts the drive assembly case 118 .
Referring now to FIG. 3 , additional thermal vias can be added at the contact area of PCB to further improve thermal performance. One side 149 of a PCB 150 includes first and second ICs 154 and 158 and/or other components 155 . The PCB 150 includes vias 160 that extend from the one side 149 of the PCB 150 to another side 151 thereof. A thermal interface material 164 thermally couples opposite ends of the vias 160 of the PCB 150 to a drive assembly case 166 . Other components of the HDD or DVD may be connected to either side of the PCB 150 as shown. Direct contact between the vias and the drive assembly case can also be used.
Referring now to FIG. 4 , for HDDs or DVDs with the external cases over the PCB, the external case can be used as a thermal heatsink by making the surface of one or more ICs directly contact the external case and/or through a thermal interface material. A PCB 200 includes first and second ICs 202 and 204 and/or other components 206 mounted thereon. The PCB 200 is mounted to the drive assembly case 210 and covered by an external cover 212 . The IC 204 includes an outer surface 219 that contacts a thermal interface material 220 . The thermal interface material 220 , in turn, contacts the external cover 212 .
Referring now to FIG. 5 , more thermal vias can be added at the contact area of PCB to further improve the thermal performance. The PCB 200 includes vias 230 that extend through and/or provide a thermal path through the PCB 200 . A thermal interface material 240 provides a thermal path between the vias and the drive assembly case 210 .
As can be appreciated, while only one IC is shown in contact with the drive assembly case in FIGS. 2-5 , the solution can be applied to two or more ICs on the PCB. Furthermore, while FIG. 2B shows direct physical contact between the drive assembly case and the IC, FIGS. 3-5 may also be arranged in direct physical contact as well. Furthermore, embodiments may include ICs in direct and/or indirect contact via the thermal interface material.
Suitable examples of thermal interface materials include thermal conductive adhesive tape, thermal conductive elastomer, thermal conductive compound and thermal grease although other thermal interface materials can be used.
Referring now to FIG. 6A , the present invention can be implemented in mass data storage and/or a DVD of a high definition television (HDTV) 420 . The HDTV 420 receives HDTV input signals in either a wired or wireless format and generates HDTV output signals for a display 426 . In some implementations, signal processing circuit and/or control circuit 422 and/or other circuits (not shown) of the HDTV 420 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other type of HDTV processing that may be required.
The HDTV 420 may communicate with mass data storage 427 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The HDTV 420 may be connected to memory 428 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The HDTV 420 also may support connections with a WLAN via a WLAN network interface 429 .
Referring now to FIG. 6B , the present invention may implement and/or be implemented in mass data storage of a vehicle control system and/or a vehicle-based DVD. In some implementations, the present invention implement a powertrain control system 432 that receives inputs from one or more sensors such as temperature sensors, pressure sensors, rotational sensors, airflow sensors and/or any other suitable sensors and/or that generates one or more output control signals such as engine operating parameters, transmission operating parameters, and/or other control signals.
The present invention may also be implemented in other control systems 440 of the vehicle 430 . The control system 440 may likewise receive signals from input sensors 442 and/or output control signals to one or more output devices 444 . In some implementations, the control system 440 may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated.
The powertrain control system 432 may communicate with mass data storage 446 that stores data in a nonvolatile manner. The mass data storage 446 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The powertrain control system 432 may be connected to memory 447 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The powertrain control system 432 also may support connections with a WLAN via a WLAN network interface 448 . The control system 440 may also include mass data storage, memory and/or a WLAN interface (all not shown).
Referring now to FIG. 6C , the present invention can be implemented in mass data storage and/or a DVD of a cellular phone 450 that may include a cellular antenna 451 . In some implementations, the cellular phone 450 includes a microphone 456 , an audio output 458 such as a speaker and/or audio output jack, a display 460 and/or an input device 462 such as a keypad, pointing device, voice actuation and/or other input device. The signal processing and/or control circuits 452 and/or other circuits (not shown) in the cellular phone 450 may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions.
The cellular phone 450 may communicate with mass data storage 464 that stores data in a nonvolatile manner such as optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The cellular phone 450 may be connected to memory 466 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The cellular phone 450 also may support connections with a WLAN via a WLAN network interface 468 .
Referring now to FIG. 6D , the present invention can be implemented in mass data storage and/or a DVD of a set top box 480 . The set top box 480 receives signals from a source such as a broadband source and outputs standard and/or high definition audio/video signals suitable for a display 488 such as a television and/or monitor and/or other video and/or audio output devices. The signal processing and/or control circuits 484 and/or other circuits (not shown) of the set top box 480 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other set top box function.
The set top box 480 may communicate with mass data storage 490 that stores data in a nonvolatile manner. The mass data storage 490 may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The set top box 480 may be connected to memory 494 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The set top box 480 also may support connections with a WLAN via a WLAN network interface 496 .
Referring now to FIG. 6E , the present invention can be implemented in mass data storage and/or a DVD of a media player 500 . In some implementations, the media player 500 includes a display 507 and/or a user input 508 such as a keypad, touchpad and the like. In some implementations, the media player 500 may employ a graphical user interface (GUI) that typically employs menus, drop down menus, icons and/or a point-and-click interface via the display 507 and/or user input 508 . The media player 500 further includes an audio output 509 such as a speaker and/or audio output jack. The signal processing and/or control circuits 504 and/or other circuits (not shown) of the media player 500 may process data, perform coding and/or encryption, perform calculations, format data and/or perform any other media player function.
The media player 500 may communicate with mass data storage 510 that stores data such as compressed audio and/or video content in a nonvolatile manner. In some implementations, the compressed audio files include files that are compliant with MP3 format or other suitable compressed audio and/or video formats. The mass data storage may include optical and/or magnetic storage devices for example hard disk drives HDD and/or DVDs. The HDD may be a mini HDD that includes one or more platters having a diameter that is smaller than approximately 1.8″. The media player 500 may be connected to memory 514 such as RAM, ROM, low latency nonvolatile memory such as flash memory and/or other suitable electronic data storage. The media player 500 also may support connections with a WLAN via a WLAN network interface 516 . Still other implementations in addition to those described above are contemplated.
Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.
|
A drive system including: a printed circuit board; a first integrated circuit mounted onto the printed circuit board; a drive assembly case that is connected to the printed circuit board; and a first thermal interface material thermally coupled between i) the printed circuit board and ii) the drive assembly case. Thermal energy generated by the first integrated circuit is dissipatable by the drive assembly case through the first interface material.
| 6
|
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is continuation in part application of our co-pending application Ser. No. 10/922,991, filed Aug. 23, 2004, which claims priority from 673/CHE/2003 filed on Aug. 22, 2003. The entire disclosures of the prior applications is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a process for the preparation of cephalosporin antibiotic of the formula (I), more particularly relates to preparation of Ceftiofur sodium of formula (I).
[0003] Ceftiofur, a semisynthetic cephalosporin, is a broad-spectrum antibiotic against both Gram-positive and Gram-negative bacteria including beta-lactamase-producing bacterial strains and anaerobes. Its antibacterial activity results from the inhibition of mucopeptide synthesis in the cell wall in a similar fashion to other cephalosporins. Ceftiofur is used in the treatment of respiratory infections in cattle and pigs. The chemical designation is [6R-[6a,7b(z)]]-7-[[(2-amino-4-thiazolyl)(methoxyimino)acetyl]amino]-3-[[2-furanylcarbonyl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid. The sodium and hydrochloride salts are administered intramuscularly and intravenously.
[0004] Ceftiofur is first disclosed in U.S. Pat. No. 4,464,367, which also discloses a process for preparing Ceftiofur and its sodium salt. U.S. Pat. No. 4,937,330 disclose a process for preparing Ceftiofur sodium, according to this patent Ceftiofur sodium was precipitated as solid from aqueous THF.
[0005] There are various literature methods reported for the preparation of cephalosporin compounds like Ceftiofur which are summarized below:
[0006] U.S. Pat. No. 5,109,131 describes a process in which 4-halo-2-methoxyimino-3-oxobutyric acid, is reacted with cephem moiety as per the scheme depicted below:
wherein R 1 stands for a C 1-4 alkyl group optionally substituted with carboxyl or a C 1-4 alkoxy-carbonyl group, R 2 stands for a halogen atom, R 3 stands for hydrogen atom or a standard cephalosporin substituent which includes Ceftiofur, and R 4 stands for hydrogen atom or a group which can be converted to hydrogen
[0007] U.S. Pat. No. 4,298,529 describes a similar process as depicted in U.S. Pat. No. 5,109,131, according to this patent the cephem compound of formula may be used as such or as a silyl derivative (column 12, lines 20-23 of U.S. Pat. No. 4,298,529).
[0008] CA 1,146,165, also discloses a similar approach for the preparation of cephalosporin compounds.
[0009] EP 0030294 discloses a process for the preparation of compound of cephalosporin antibiotic as given in scheme 1:
[0010] GB 2012276 describes 7-(4-halogeno-3-oxo-2-alkoxyiminobutyrylamino) cephalosporin derivative of the formula (XIII)
wherein X represents a halogen atom, R 3 represents —CH 2 R 5 (R 5 is hydrogen atom or the residue of a nucleophilic compound), a halogen atom, an alkoxyl group, thiol group, amino group etc., —COOR 4 represents a carboxylic group that may be esterified, and R 6 represents an alkyl group and also a process for preparing a 7-[2-(2-aminothiazol-4-yl)-2-(syn)-alkoxyiminoacetamido] cephalosporin derivatives of the formula (XIV)
[0011] U.S. Pat. No. 6,552,186 relates to the preparation of ceftriaxone and cefotaxime also claims a process for the preparation of number of cephalosporin antibiotic including Ceftiofur using similar approach disclosed in prior art. As cited by U.S. Publication No. 2005/0059820, this patents itself obvious and anticipated over various prior art. Moreover this patent utilizes two phase solvent system for cyclization stage; one of the disadvantages with this two phase solvent system during cyclization with thiourea is that the reaction takes more times for completion or many times the reaction will not proceed for completion leaving 7% to 15% starting material, and affording less pure product.
[0012] Thus the above literature reports like CA 1,146,165, U.S. Pat. No. 4,298,529 and U.S. Pat. No. 5,109,131 (which were published after the grant of U.S. Pat. No. 4,464,367, where Ceftiofur was first disclosed) and U.S. Pat. No. 6,552,186 pertaining towards the preparation of Cephalosporin antibiotics suggest and teach the following general scheme for the preparation of Ceftioflir of formula (I):
[0013] Though the literature pertains to cephalosporin chemistry, which suggests or motivates the above general process, U.S. Pat. No. 6,458,949 claims a similar process for preparing Ceftiofur. According to this patent the purity of final Ceftiofur depends critically on the isolation of compound of formula (C). Claim 7 of this patent reads that “starting” with compound of formula (C), which clearly indicates the isolation of formula (C) is crucial as per this patent. This patent also acknowledges that cyclization of compound of formula (C) in situ with thiourea in the presence of a base yields impure Ceftiofur and further purifications are difficult, time consuming and do not result in a product of good quality. Also this patent claims the compound of formula (C) though it is obvious over cephalosporin chemistry.
[0014] Interestingly, in our continued research we have identified a simple process for the preparation of Ceftiofur, in which even though the compound of formula (C) is not isolated, it yields Ceftiofur in highly pure form. The in situ process of this invention avoids the time-consuming isolation step of the intermediate and makes overall process commercially viable with reduced time-cycle and economical. None of the prior art suggests or even motivates the present invention.
SUMMARY
[0015] An objective of the invention is to provide an improved process for the preparation of cephalosporin antibiotic of the formula (I), without isolating the compound of formula (IV).
[0016] Another objective of the present invention is to provide an improved process for the preparation of Ceftiofur sodium of the formula (I) in high purity and yield.
[0017] Accordingly, the present invention provides an improved process for the preparation of Ceftiofur sodium of the formula (I)
which comprises:
(i) activating the compound of formula (E) as acid chloride of formula (Ea) in an organic solvent
where X represents halogen atom such as chlorine or bromine, using a halogenating agent,
(ii) treating the reaction mass obtained from step (i) with water at a temperature in the range of −40° C. to 10° C.,
(iii) separating the organic layer containing the activated derivative of formula (IIIa) and condensing the activated derivative of the formula (IIIa)
where X represents halogen atom such as chlorine or bromine, with 7-amino cephalosporin derivative (FURACA) of the formula (II) or its reactive derivative
wherein R′ represents hydrogen, or silyl and R″ represents hydrogen or silyl in the presence of a solvent and in the presence or absence of base at a temperature in the range of −50° C. to 10° C. to produce a compound of formula (IV)
where all symbols are as defined above, and
iv) optionally removing the solvent of step (iii) reaction mass and cyclizing the compound of formula (IV) with thiourea, in water, in the presence or absence of water miscible solvent and sodium ion source, at a temperature in the range of −50 to 30° C. to produce compound of formula (I), wherein the improvement comprises producing the compound of formula (I) without isolating compound of formula (IV), and also characterized by one or more of the following improvements:
a) removing the solvent in step (iii), b) conducting the reaction of step (iv) in a homogeneous solvent system.
[0020] The said process is depicted as below:
DETAILED DESCRIPTION OF EMBODIMENTS
[0021] In an embodiment of the present invention the halogenating agent for activating the acid of formula (III) in step (i) is selected from PCl 5 , PCl 3 , POCl 3 , SOCl 2 and the like, and the organic solvent employed in step (i) is selected from dichloromethane, ethyl acetate, THF, DMF and the like or any inert solvent can be employed.
[0022] In another embodiment of the present invention the treatment of step (i) reaction mass with water at low temperatures removes the impurities formed. Because of this treatment, Ceftiofur sodium was obtained in pure form even without isolating the compound of formula (IV). This constitutes one of the advantages of the present invention.
[0023] In still another embodiment of the present invention, the condensation of FURACA of formula (II) with (IIIa) is performed in the presence of a solvent selected from dichloromethane, ethyl acetate, methanol, ethanol, isopropanol, isobutyl alcohol, n-propanol, n-butanol, tert-butanol, tetrahydrofuran, aromatic hydrocarbons, acetone, ethyl methyl ketone, diethyl ketone, pentan-3-one, cyclohexanone, methyl isobutyl ketone, dioxane, acetonitrile, DMAc, N,N-dimethylformamide, dialkylethers, ethylene glycol, ethylene glycol monomethyl ether, diglyme, monoglyme, diethylene glycol, triethylene glycol, polyethylene glycol, water and the like or mixtures thereof.
[0024] In yet another embodiment of the present invention, the base used in step (iii) is selected from ammonia, sodium carbonate, sodium bicarbonate, ammonium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, trimethyl amine and the like. The presence of base facilitates the condensation, when the compound of formula (II) is employed in free form. Accordingly the base is necessary when the compound of formula (II) is employed in free form and it is not essential when the compound of formula (II) is employed in the form of silylated derivative.
[0025] In yet another embodiment of the present invention, the compound of formula (IV) is prepared by condensing the reactive derivative of compound of formula (II), wherein the reactive derivate is silylated form of formula (II), with (IIIa). Silylated form of formula (II) is prepared by treating the compound of formula (II) with silylating agents like hexamethyldisilazane (HMDS), trimethylsilyl chloride (TMCS), bistrimethylsilyl urea (BSU), N,O-Bistrimethylsilyl acetamide (BSA) and the like in the presence or absence of catalyst like N-methyl morpholine, acetamide and imidazole. The solvent used for silylation and subsequent condensation is selected from dichloromethane, N,N-dimethylformamide, N,N-dimethylacetamide, acetonitrile, toluene and the like or mixtures thereof more particularly dichloromethane.
[0026] In another embodiment of the present invention the solvent employed for silylation and subsequent condensation can be removed by either distillation or by any conventional method so as to conduct the cyclization step in homogeneous solvent system. Conventional method involves quenching of this reaction mass to methanol or water. However, it has been observed the impurity formation in conventional method is high when compared to distillation, which is an advantage of the present invention. It has been also observed that the conventional two-phase solvent system takes more time for cyclization, and produces less pure Ceftiofur.
[0027] In still another embodiment of the present invention, the present invention was performed without isolating the compound of formula (IV), which makes the reaction as one pot, which is also considered to be one of the advantages of the present invention.
[0028] In yet another embodiment of the present invention, the cyclization of compound of (IV) is carried out using water miscible solvent selected from tetrahydrofuran, acetone, ethyl methyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, cyclohexanone, diethyl ketone, pentan-3-one, cyclohexanone, acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, dioxane, (C 1 -C 5 )alcohol, ethylene glycol, diglyme, monoglyme, ethylene glycol monomethyl ether, diethylene glycol, triethylene glycol, polyethylene glycol and the like or mixtures there of, and sodium ion source employed in step (iv) is selected from sodium acetate, sodium carbonate, sodium bicarbonate, sodium methoxide, sodium 2-ethyl hexonate, sodium ethoxide and the like.
[0029] In still another embodiment of the present invention, the Ceftiofur sodium is isolated directly from the reaction mass comprising water miscible organic solvent and water. Most preferably precipitating Ceftiofur sodium from the reaction mass containing THF/water. The Ceftiofur sodium thus obtained was purified by either dissolving Ceftiofur sodium in water followed by isolating pure Ceftiofur sodium by adding sodium salt of mineral acid such as sodium chloride, or converting the Ceftiofur sodium into Ceftiofur TFA salt followed by converting Ceftiofur TFA salt into Ceftiofur sodium.
[0030] The starting material of the present invention can be prepared by utilizing the process available in the prior art.
[0031] The present invention is provided by the examples below, which are provided by way of illustration only and should not be considered to limit the scope of the invention.
EXAMPLE 1
[0032] Preparation of Ceftiofur Sodium:
[0033] To a solution of 4-chloro-2-methoxyimino-3-oxobutyric acid (60.67 g) in dichloromethane (400 ml), phosphorus pentachloride (73.49 g) was added at −15 to −10° C. under nitrogen atmosphere. The reaction mass was stirred at −10 to −5° C. and washed with chilled purified water at 0-5° C. The organic layer was separated and added to a silylated solution of FURACA (prepared by treating suspension of FURACA (100 g) in dichloromethane (500 ml) with TMCS (24.52 g) and HMDS (36.4 g)) at −40 to −50° C.). After completion of reaction dichloromethane was distilled out under vacuum at 25-30° C. To the residue, aqueous THF (1000 mL) and thiourea (48 g) were added and stirred by maintaining pH at 4.0-8.0 using sodium bicarbonate at 10-20° C. After completion of the reaction, EDTA (5 g), sodium hydrosulphite (5 g) were added and cooled to 0-5° C. The solid obtained was filtered, washed with THF and dried under vacuum to yield pure title compound (107 g; purity by HPLC 99.28%).
EXAMPLE 2
[0034] Preparation of Ceftiofur Sodium:
[0035] To the solution of 4-chloro-2-methoxyimino-3-oxobutyric acid (60.67 g) in dichloromethane (400 ml), phosphorus pentachloride (73.49 g) was added at −15 to −10° C. under nitrogen atmosphere. The reaction mass was stirred at −10 to −5° C. and washed with chilled purified water at 0-5° C. The organic layer was separated and added to a silylated solution of FURACA (prepared by treating suspension of FURACA (100 g) in dichloromethane (500 ml) with TMCS (24.52 g) and HMDS (36.4 g) at 10-20° C. and stirred to get clear solution at 25-30° C.) at −40 to −50° C. After completion of reaction dichloromethane was distilled out under vacuum at 25-30° C. To the residue THF (500 ml), DM water (500 ml) and thiourea (48 g) were added and stirred by maintaining pH at 5.0-8.0 using sodium bicarbonate at 18-22° C. To the reaction mixture was added sodium chloride (30 g) and separated aqueous layer. To the aqueous layer sodium chloride was added and stirred. The precipitated solid was filtered and washed with THF. Drying the solid under vacuum afforded pure title compound. (98 g, Purity by HPLC 98.48%).
EXAMPLE 3
[0036] Preparation of Ceftiofur Sodium (without Silylating FURACA):
[0037] To the solution of 4-chloro-2-methoxyimino-3-oxobutyric acid (60.67 g) in dichloromethane (400 ml), phosphorus pentachloride (73.49 g) was added at −15 to −10° C. under nitrogen atmosphere. The reaction mass was stirred at −10 to −5° C. and washed with chilled purified water at 0-5° C. The organic layer was separated and added to a suspension of Furaca (100 g) in aqueous THF (20% & 1000 ml) by maintaining the pH at 5.5 to 8.5 using aqueous ammonia. To the reaction mixture was added thiourea (48 g) and the pH maintained in the range 5.0 to 8.0 using sodium bicarbonate. After completion of the reaction, THF was added to the reaction mass and cooled to 0° C. The solid obtained was filtered and washed with THF and dried under vacuum to yield pure title compound. (80 g; purity by HPLC 98.4 to 98.98).
EXAMPLE 4
[0038] Preparation of Ceftiofur TFA Salt into Ceftiofur Sodium:
[0039] To the solution of Ceftiofur TFA salt in THF, triethylamine was added and adjusted the pH to 5.0-8.0. To the clear solution sodium 2-ethyl hexonate in THF was added at 0-25° C. The solid obtained was filtered and dried to get Ceftiofur sodium (99.7%) in pure form.
[0040] Preparation of Ceftiofur Sodium from Ceftiofur TFA salt:
[0041] To the solution of Ceftiofur TFA salt in THF, triethylamine was added and adjusted the pH to 5.0-8.0. To the clear solution sodium 2-ethylhexonate in THF was added at 0-25° C. The solid obtained was filtered and dried to get Ceftiofur sodium (purity 99.3 to 99.7%) in pure form.
|
An improved process for the preparation of Ceftiofar sodium of formula (I) without isolating intermediate compound of formula (IV)
| 2
|
[0001] The application claims priority to U.S. Provisional Application No. 60/530,390, which was filed on Dec. 17, 2003.
BACKGROUND OF THE INVENTION
[0002] A tire pressure-monitoring device provides information on current tire conditions. The conditions within the tire that are monitored by the device include air pressure, temperature and other characteristics indicative of current tire conditions. The tire pressure-monitoring device is most often included as a part of the tire air valve assembly. In this way the tire pressure-monitoring device is assembled along with the tire air valve into an opening provided within a wheel rim. Such installation techniques require that the wheel rim be fitted with a counter balance to offset the imbalance created by the added weight of the tire pressure monitoring system on the valve stem. Further, the joint between the valve stem body and a wheel rim is susceptible to corrosion due to electrolytic reactions caused by brake dust against the junction between the valve stem and the wheel rim.
[0003] It is also known to secure a tire pressure monitoring device within the tire well of a wheel rim with a strap that extends about the circumference of the wheel. This strap is tightened down against the wheel and provides for the mounting of the tire pressure-monitoring device independent of the valve stem. The strap is most often a metal strap that is drawn tight by mechanical fastening means.
[0004] As appreciated, such methods of mounting a tire pressure-monitoring device create certain challenges to assembly and durability of a wheel assembly. It is therefore desirable to design a mounting configuration for a tire pressure-monitoring device that does not adversely affect tire balance and also that provides a durable reliable connection. Further, it is desirable to develop a method for securing a tire-monitoring device within a wheel that is cost effective to assembly.
SUMMARY OF THE INVENTION
[0005] The example tire pressure monitoring mounting device of this invention includes a bracket that is welded to an inner surface of a wheel rim.
[0006] This invention includes a method of securing a bracket or a tire pressure monitoring device within a tire well of a rim utilizing a friction welding technique. The method includes a step of holding a bracket assembly against a wheel rim in a desired location. The bracket assembly includes a weld surface that corresponds to a surface on the wheel rim. The weld surface includes a common curvature that matches the surface of the wheel and also includes a material compatible with welding to the wheel rim.
[0007] The wheel is rotated relative to the bracket assembly at a speed that combined with a downward force will generate heat both in the bracket and in the wheel to create a weld. Once a sufficient amount of heat has generated by the relative rotation between the bracket and the wheel. The wheel is stopped with the bracket in a desired location. An added force is exerted on the bracket to complete the weld. Once the bracket and wheel have cooled the bracket is welded and becomes an integral part of the wheel assembly.
[0008] Once the bracket is secured to the wheel assembly the tire pressure monitoring device can be attached to the bracket. The bracket can comprise any type of clip that corresponds to the features of the tire pressure-monitoring device.
[0009] Accordingly, the method and assembly of this invention provides a robust, reliable, and cost effective way of securing a tire pressure-monitoring sensor within a wheel assembly.
[0010] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cut away view of a tire assembly including a tire pressure-monitoring device mounted according to this invention.
[0012] FIG. 2 is a cross-sectional view of the tire assembly with the tire pressure-monitoring device mounted according to this invention.
[0013] FIG. 3 is a cross-sectional view of the tire pressure-monitoring device mounted to a wheel according to this invention.
[0014] FIG. 4 is a schematic view of an attachment means between the bracket assembly and tire pressure-monitoring device.
[0015] FIG. 5 is another top view of a tire pressure-monitoring configuration according to this invention.
[0016] FIG. 6 is a cross-sectional view of another tire pressure monitoring device mounted to a wheel according to this invention.
[0017] FIG. 7 is a block diagram illustrating a method of securing and welding a tire pressure monitoring attachment device to a wheel assembly according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIG. 1 , a wheel assembly 10 includes a tire 12 mounted to a rim 14 . A bracket 18 is mounted to an inner surface 20 of the rim 14 and supports a tire pressure monitoring assembly 16 . The bracket 18 is welded to the inner surface 20 of the rim 14 . The bracket 18 is friction welded to the inner surface 20 . Although friction welding is shown and discussed it is within the contemplation of this invention to secure the bracket 18 to the inner surface 20 of the wheel rim 14 by any welding means known to a worker versed in the art.
[0019] Referring to FIG. 2 , the tire 12 is mounted to the rim 14 and defines a tire well 26 . The tire well 26 is a portion of the rim 14 between the outermost walls that support attachment of the tire 12 . The specific shape of the tire well 26 is as commonly known. The wheel inner surface 20 of the wheel rim 14 includes a surface that corresponds to the desired configuration of the wheel assembly 10 . That is, the inner surface 20 is not a planar surface in that there are specific curved surfaces and contours that are required to provide for mounting of the tire 12 and to accommodate mounting configurations for the wheel assembly 10 .
[0020] The bracket 18 secures the tire pressure-monitoring assembly 16 to a surface of the wheel rim 14 that is offset from a centerline. The specific location of the tire pressure monitoring assembly 16 is provided to minimize any imbalance that may be caused by the additional weight and mass of the tire pressure monitoring assembly 16 .
[0021] The tire pressure monitoring assembly 16 includes a plurality of electronics 24 . Typically, the electronics 24 include sensors for sensing pressure and temperature within the tire and a transmitter for transmitting signals indicative of conditions within the tire 12 to an external controller. The specific configuration of the tire pressure monitoring assembly 16 is as known. A worker skilled in the art with the benefit of this disclosure would understand that many different tire pressure-monitoring devices are within the contemplation of this invention.
[0022] The bracket 18 is welded to the rim 14 along the inner surface 20 . The tire pressure-monitoring assembly 16 is in turn attached to the bracket 18 . In one example, the bracket 18 is friction welded to the wheel rim, however, other welding methods such as spot welding, brazing and laser welding are within the contemplation of this invention.
[0023] Referring to FIG. 3 , an enlarged cross-sectional view of the tire pressure monitoring assembly 16 is shown mounted to the bracket 18 . The tire pressure monitoring assembly 16 includes a housing 22 that is filled with a potting material 28 that supports and protects the electronics 24 . Bracket 18 includes a clip 30 that holds the housing 22 in its desire location. The bracket 18 also includes a weld segment 32 . The weld segment 32 corresponds with the inner surface of the wheel rim 14 and provides for welding of the bracket 18 to the inner surface 20 of the wheel rim 14 .
[0024] In a friction welding process, a force schematically indicated by arrows 50 is exerted downwardly on the bracket 18 to hold the bracket 18 against an inner surface 20 of the wheel rim 14 . The wheel rim 14 is then rotated at a speed that generates sufficient heat both in the bracket 18 and in the localized surfaces of the wheel rim 14 that correspond to the position of the bracket 18 . Upon the sufficient generation of heat between the bracket 18 and the inner surface 20 the wheel rim 14 is stopped. An additional force is exerted upon the bracket 18 downwardly to force the bracket 18 against the wheel rim 14 to complete the friction welding operation. Once the bracket 18 and wheel rim 14 has cooled the bracket 18 will be welded to the wheel rim 14 and secured there in place.
[0025] The tire pressure monitoring assembly 16 can than be clipped into the bracket 18 by way of the clip 30 . The clip 30 as is shown in FIG. 3 comprises a lip portion 31 and tab portion 33 . The lip portion 31 and tab portion 33 cooperate with features of the housing 22 to secure the tire pressure monitoring assembly 16 to the bracket 18 . A specific configuration of a clip 30 for securing the housing 22 to the bracket 18 is shown in FIG. 3 . A worker versed in the art with the benefit of this disclosure would understand that other clip configurations as are known are also within the contemplation of this invention.
[0026] Referring to FIG. 4 , another bracket 15 is illustrated that includes clip 33 . The clip 33 includes two elongated arms 35 that provide a tensile force to secure the housing 22 . The housing 22 includes flat surfaces that correspond with the clip 33 . The housing 22 is simply slid under the clip 33 and held there in place.
[0027] Referring to FIG. 5 , another tire pressure monitoring assembly 16 is illustrated along with another bracket 17 . The bracket 17 that includes a tab 36 that corresponds with slot 34 disposed within the housing 22 . The housing 22 is then slid onto and secured by the tabs 36 . The tabs 36 compress to allow the tabs 36 to fit through the slot 34 and then expand outwardly from the slot 34 to prevent removal of the housing 22 .
[0028] Referring to FIG. 6 , another bracket 19 according to this invention is illustrated that includes the tire pressure monitoring assembly 16 . In this embodiment the tire pressure monitoring assembly 16 is integrally formed within the bracket 19 . The bracket 19 defines a cavity into which the electronics 24 are placed. Potting 28 is then utilized to fill the cavity in which the electronics 24 is placed to support the electronics and protect them. The bracket 18 is then friction welded to the wheel rim 14 . In this way no clip configuration is required in that the tire pressure-monitoring device sticks permanently to the wheel rim 14 . Further, the number of component parts is reduced. In this embodiment, the bracket 19 includes the weld segment 32 and also finds portions of the housing 22 that define the space into which the electronics 24 for the tire pressure-monitoring assembly 16 are secured.
[0029] Referring to FIG. 7 , a block diagram schematically illustrating the method of securing the tire pressure monitoring assembly 16 of this invention is shown. In a first step 40 indicated and illustrated at 42 a bracket 18 is placed and held under a force 50 against the surface of the wheel rim 14 . Location step 44 includes the step of applying a force on the bracket 18 against the rotating rim 14 to generate heat in the bracket 18 and in the wheel rim 14 . The interface is schematically indicated and shown at 45 between the wheel rim 14 and bracket 18 that generates sufficient heat to melt the materials in both the bracket 18 and the rim 14 to a point as to enable a bond to be formed between the two.
[0030] Once a desired amount of heat has been generated both in the bracket 18 and in the wheel rim 14 , the rim 14 is stopped at a desired mounting location on the rim 14 . This location is pre-determined such that the tire pressure monitoring assembly 16 will be placed in a location on the wheel that provides and minimizes potential counter balance requirements. Once the rim 14 has stopped rotating an additional force 51 is added to press the bracket 18 against the wheel rim 14 . The additional forces as indicated at step 46 provide for adhesion between wheel rim 14 and bracket 18 . The specific rotational speed and forces required to build the friction and generate the heat required are as known to a worker skilled in the art. A worker skilled in the art with the benefit of this disclosure would understand how to apply friction-welding techniques to the mounting of the tire pressure-monitoring bracket 18 to the wheel rim 14 . Once the bracket 18 has been bonded and adhered to the rim 14 the tire pressure monitoring assembly 16 is mounted to the bracket 18 . Alternatively, as is shown in FIG. 6 , the electronics are already mounted within the bracket 18 and therefore is already mounted in the proper location.
[0031] Accordingly, the method in the place of this invention provides an effective reliable and cost-effective means of securing a tire pressure monitoring system within a wheel assembly.
[0032] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
|
A method of securing a tire pressure-monitoring device to a vehicle wheel includes the steps of welding a bracket within a tire wheel well. The bracket assembly includes a weld surface that corresponds to a surface on the wheel rim. The weld surface includes a common curvature that matches the surface of the wheel and also includes a material compatible with welding to the wheel rim.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Prov. Pat. App. No. 60/866,322 (Atty. Dock. No. WEAT/0749L), entitled “Top Drive Backout Interlock Method”, filed on Nov. 17, 2006, which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to methods and apparatus for improving top drive operations.
[0004] 2. Description of the Related Art
[0005] It is known in the industry to use top drive systems to rotate a drill string to form a borehole. Top drive systems are equipped with a motor to provide torque for rotating the drilling string. The quill of the top drive is typically threadedly connected to an upper end of the drill pipe in order to transmit torque to the drill pipe. Top drives may also be used in a drilling with casing operation to rotate the casing.
[0006] To drill with casing, most existing top drives use a threaded crossover adapter to connect to the casing. This is because the quill of the top drives is typically not sized to connect with the threads of the casing. The crossover adapter is design to alleviate this problem. Generally, one end of the crossover adapter is designed to connect with the quill, while the other end is designed to connect with the casing. In this respect, the top drive may be adapted to retain a casing using a threaded connection.
[0007] However, the process of connecting and disconnecting a casing using a threaded connection is time consuming. For example, each time a new casing is added, the casing string must be disconnected from the crossover adapter. Thereafter, the crossover must be threaded to the new casing before the casing string may be run. Furthermore, the threading process also increases the likelihood of damage to the threads, thereby increasing the potential for downtime.
[0008] As an alternative to the threaded connection, top drives may be equipped with tubular gripping heads to facilitate the exchange of wellbore tubulars such as casing or drill pipe. Generally, tubular gripping heads have an adapter for connection to the quill of top drive and gripping members for gripping the wellbore tubular. Tubular gripping heads include an external gripping device such as a torque head or an internal gripping device such as a spear. An exemplary torque head is described in U.S. Patent Application Publication No. 2005/0257933, filed by Pietras on May 20, 2004, which is herein incorporated by reference in its entirety. An exemplary spear is described in U.S. Patent Application Publication Number US 2005/0269105, filed by Pietras on May 13, 2005, which is herein incorporated by reference in its entirety.
[0009] In most cases, the adapter of the tubular gripping head connects to the quill of the top drive using a threaded connection. The adapter may be connected to the quill either directly or indirectly, e.g., through another component such as a sacrificial saver sub. One problem that may occur with the threaded connection is inadvertent breakout of that connection during operation. For example, in a drilling with casing operation, a casing connection may be required to be backed out (i.e., unthreaded) either during the pulling of a casing string or to correct an unacceptable makeup. It may be possible that the left hand torque required to break out the casing connection exceeds the breakout torque of the connection between the adapter and the quill, thereby inadvertently disconnecting the adapter from the quill and creating a hazardous situation on the rig.
[0010] There is a need, therefore, for methods and apparatus for ensuring safe operation of a top drive.
SUMMARY OF THE INVENTION
[0011] Embodiments of the present invention generally relate to methods and apparatus for improving top drive operations. In one embodiment a method of ensuring safe operation of a top drive includes operating a top drive, thereby exerting torque on a first tubular to makeup or breakout a first threaded connection between the first tubular and a second tubular. The method further includes monitoring for break-out of a second connection between a quill of the top drive and the first tubular; and stopping operation of the top drive and/or notifying an operator of the top drive if break-out of the second connection is detected.
[0012] In another embodiment, a method of ensuring safe operation of a top drive includes operating a top drive, thereby rotating a quill of the top drive. The quill of the top drive is connected to a torque head or a spear. Hydraulic communication between the torque head or spear and a hydraulic pump is provided by a swivel. A bearing is disposed between a housing and a shaft of the swivel. The method further includes determining acceptability of operation of the bearing by monitoring a torque exerted on the swivel housing by the bearing; and stopping operation of the top drive and/or notifying an operator of the top drive if the bearing operation is unacceptable.
[0013] In another embodiment, a torque head or spear for use with a top drive includes a body having an end for forming a connection with a quill of the top drive; a gripping mechanism operably connected to the body for longitudinally and rotationally gripping a tubular; and a computer configured to perform an operation. The operation includes monitoring for break-out of the connection; and stopping operation of the top drive and/or notifying an operator of the top drive if break-out of the connection is detected.
[0014] In another embodiment, a torque head or spear for use with a top drive includes a body having an end for forming a connection with a quill of the top drive; a gripping mechanism operably connected to the body for longitudinally and rotationally gripping a tubular; and a swivel. The swivel includes a housing; a shaft disposed in the housing and connected to the body; a bearing disposed between the shaft and the housing; and a strain gage disposed on the housing and operable to indicate torque exerted on the housing by the bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0016] FIG. 1 is a partial view of a rig having a top drive system.
[0017] FIG. 2 is an isometric view of a torque sub usable with the top drive system. FIG. 2A is a side view of a torque shaft of the torque sub. FIG. 2B is an end view of the torque shaft with a partial sectional view cut along line 2 B- 2 B of FIG. 2A . FIG. 2C is a cross section of FIG. 2A . FIG. 2D is an isometric view of the torque shaft. FIG. 2E is an electrical diagram showing data and electrical communication between the torque shaft and a housing of the torque sub.
[0018] FIG. 3 is a block diagram illustrating a tubular make-up system, according to one embodiment of the present invention.
[0019] FIG. 4 is a side view of a top drive system employing a torque meter. FIG. 4A is an enlargement of a portion of FIG. 4 . FIG. 4B is an enlargement of another portion of FIG. 4 .
[0020] FIG. 5 is a flow chart illustrating operation of an interlock of the make-up system of FIG. 3 , according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0021] FIG. 1 shows a drilling rig 10 applicable to drilling with casing operations or a wellbore operation that involves picking up/laying down tubulars. The drilling rig 10 is located above a formation at a surface of a well. The drilling rig 10 includes a rig floor 20 and a v-door 800 . The rig floor 20 has a hole 55 therethrough, the center of which is termed the well center. A spider 60 is disposed around or within the hole 55 to grippingly engage the casings 30 , 65 at various stages of the drilling operation. As used herein, each casing 30 , 65 may include a single casing or a casing string having more than one casing. Furthermore, aspects of the present invention are equally applicable to other types of wellbore tubulars, such as drill pipe.
[0022] The drilling rig 10 includes a traveling block 35 suspended by cables 75 above the rig floor 20 . The traveling block 35 holds the top drive 50 above the rig floor 20 and may be caused to move the top drive 50 longitudinally. The top drive 50 may be supported by the travelling block 35 using a swivel which allows injection of drilling fluid into the top drive 50 . The top drive 50 includes a motor 80 which is used to rotate the casing 30 , 65 at various stages of the operation, such as during drilling with casing or while making up or breaking out a connection between the casings 30 , 65 . A railing system (partially shown) is coupled to the top drive 50 to guide the longitudinal movement of the top drive 50 and to prevent the top drive 50 from rotational movement during rotation of the casings 30 , 65 .
[0023] Disposed below the top drive 50 is a tubular gripping member such as a torque head 40 . The torque head 40 may be utilized to grip an upper portion of the casing 30 and impart torque from the top drive to the casing 30 . The torque head 40 may be coupled to an elevator 70 using one or more bails 85 to facilitate the movement of the casing 30 above the rig floor 20 . In another embodiment, the bails 85 may be coupled to the top drive 50 or components attached thereto. Additionally, the rig 10 may include a pipe handling arm 100 to assist in aligning the tubulars 30 , 65 for connection. In must be noted that other tubular gripping members such as a spear are contemplated for use with the top drive. An exemplary torque head suitable for use with a top drive 50 is disclosed in U.S. Patent Application Publication No. 2005/0257933, filed by Pietras on May 20, 2004, which is herein incorporated by reference in its entirety. An exemplary spear is described in U.S. Patent Application Publication Number US 2005/0269105, filed by Pietras on May 13, 2005, which is herein incorporated by reference in its entirety.
[0024] Torque Sub
[0025] FIG. 2 shows an exemplary torque sub/swivel 600 . The torque sub 600 may be connected to the top drive 50 for measuring a torque applied by the top drive 50 . The torque sub 600 may be disposed between the top drive 50 and the torque head 40 . The swivel 600 may provide hydraulic communication between stationary hydraulic lines and the torque head 40 for operation thereof. The torque sub/swivel 600 may include a swivel housing 605 , a swivel shaft 612 , a torque shaft 610 , an interface 615 , and a controller 620 . The swivel housing 605 is a tubular member having a bore therethrough. Longitudinally and rotationally coupled to the housing 605 is a bracket 605 a for coupling the swivel housing 605 to the railing system, thereby preventing rotation of the swivel housing 605 during rotation of the top drive 50 , but allowing for vertical movement of the swivel housing 605 with the top drive 50 under the traveling block 35 . The interface 615 and the controller 620 are both mounted on the swivel housing 605 . The controller 620 and the torque shaft 610 may be made from metal, such as stainless steel. The interface 615 may be made from a polymer. The bails 85 may also be pivoted to the swivel housing 605 . The torque shaft 610 and the swivel shaft 612 are disposed in the bore of the swivel housing 605 . The swivel shaft 612 is disposed between the torque shaft 610 and the swivel housing 605 and rotationally coupled to the torque shaft 610 a . The swivel housing 605 is supported from the swivel shaft 612 by one or more swivel bearings (not shown) to allow rotation of the swivel shaft 612 relative to the swivel housing 605 .
[0026] FIG. 2A is a side view of the torque shaft 610 of the torque sub 600 . FIG. 2B is an end view of the torque shaft 610 with a partial sectional view cut along line 2 B- 2 B of FIG. 2A . FIG. 2C is a cross section of FIG. 2A . FIG. 2D is an isometric view of the torque shaft 610 . The torque shaft 610 is a tubular member having a flow bore therethrough. The torque shaft 610 includes a threaded box 610 a , a groove 610 b , one or more longitudinal slots 610 c (preferably two), a reduced diameter portion 610 d , and a threaded pin 610 e , a metal sleeve 610 f , and a polymer (preferably rubber, more preferably silicon rubber) shield 610 g.
[0027] The threaded box 610 a receives the quill of the top drive 50 , thereby forming a rotational connection therewith. Other equipment, such as a thread saver sub or a thread compensator (not shown), may be connected between the torque sub/swivel 600 and the quill. The pin 610 e is received by a connector of the torque head 40 , thereby forming a rotational connection therewith. A failsafe, such as set screws, may be added to the toque sub 610 /torque head 40 connection. The groove 610 b receives a secondary coil 630 b (see FIG. 2E ) which is wrapped therearound. Disposed on an outer surface of the reduced diameter portion 610 d are one or more strain gages 680 . Each strain gage 680 may be made of a thin foil grid and bonded to the tapered portion 610 d of the shaft 610 by a polymer support, such as an epoxy glue. The foil strain gauges 680 are made from metal, such as platinum, tungsten/nickel, or chromium. Four strain gages 680 may be arranged in a Wheatstone bridge configuration. The strain gages 680 are disposed on the reduced diameter portion 610 d at a sufficient distance from either taper so that stress/strain transition effects at the tapers are fully dissipated. The slots 610 c provide a path for wiring between the secondary coil 630 b and the strain gages 680 and also house an antenna 645 a (see FIG. 2E ).
[0028] The shield 610 g is disposed proximate to the outer surface of the reduced diameter portion 610 d . The shield 610 g may be applied as a coating or thick film over strain gages 680 . Disposed between the shield 610 g and the sleeve 610 f are electronic components 635 , 640 (see FIG. 2E ). The electronic components 635 , 640 are encased in a polymer mold 630 (see FIG. 2E ). The shield 610 g absorbs any forces that the mold 630 may otherwise exert on the strain gages 680 due to the hardening of the mold. The shield 610 g also protects the delicate strain gages 680 from any chemicals present at the wellsite that may otherwise be inadvertently splattered on the strain gages 680 . The sleeve 610 f is disposed along the reduced diameter portion 610 d . A recess is formed in each of the tapers to seat the shield 610 f . The sleeve 610 f forms a substantially continuous outside diameter of the torque shaft 610 through the reduced diameter portion 610 d . Preferably, the sleeve 610 f is made from sheet metal and welded to the shaft 610 . The sleeve 610 f also has an injection port formed therethrough (not shown) for filling fluid mold material to encase the electronic components 635 , 640 .
[0029] FIG. 2E is an electrical diagram showing data and electrical communication between the torque shaft 610 and the enclosure 605 . A power source 660 may be provided in the form of a battery pack in the controller 620 , an-onsite generator, utility lines, or other suitable power source. The power source 660 is electrically coupled to a sine wave generator 650 . Preferably, the sine wave generator 650 will output a sine wave signal having a frequency less than nine kHz to avoid electromagnetic interference. The sine wave generator 650 is in electrical communication with a primary coil 630 a of an electrical power coupling 630 .
[0030] The electrical power coupling 630 is an inductive energy transfer device. Even though the coupling 630 transfers energy between the stationary interface 615 and the rotatable torque shaft 610 , the coupling 630 is devoid of any mechanical contact between the interface 615 and the torque shaft 610 . In general, the coupling 630 acts similar to a common transformer in that it employs electromagnetic induction to transfer electrical energy from one circuit, via its primary coil 630 a , to another, via its secondary coil 630 b , and does so without direct connection between circuits. The coupling 630 includes the secondary coil 630 b mounted on the rotatable torque shaft 610 . The primary 630 a and secondary 630 b coils are structurally decoupled from each other.
[0031] The primary coil 630 a may be encased in a polymer 627 a , such as epoxy. The secondary coil 630 b may be wrapped around a coil housing 627 b disposed in the groove 610 b . The coil housing 627 b is made from a polymer and may be assembled from two halves to facilitate insertion around the groove 610 b . Optionally, the secondary coil 630 b is then molded in the coil housing 627 b with a polymer. The primary 630 a and secondary coils 630 b are made from an electrically conductive material, such as copper, copper alloy, aluminum, or aluminum alloy. The primary 630 a and/or secondary 630 b coils may be jacketed with an insulating polymer. In operation, the alternating current (AC) signal generated by sine wave generator 650 is applied to the primary coil 630 a . When the AC flows through the primary coil 630 a , the resulting magnetic flux induces an AC signal across the secondary coil 630 b . The induced voltage causes a current to flow to rectifier and direct current (DC) voltage regulator (DCRR) 635 . A constant power is transmitted to the DCRR 635 , even when torque shaft 610 is rotated by the top drive 100 . The primary coil 630 a and the secondary coil 630 b have their parameters (i.e., number of wrapped wires) selected so that an appropriate voltage may be generated by the sine wave generator 650 and applied to the primary coil 630 a to develop an output signal across the secondary coil 630 b.
[0032] The DCRR 635 converts the induced AC signal from the secondary coil 630 b into a suitable DC signal for use by the other electrical components of the torque shaft 610 . In one embodiment, the DCRR outputs a first signal to the strain gages 680 and a second signal to an amplifier and microprocessor controller (AMC) 640 . The first signal is split into sub-signals which flow across the strain gages 680 , are then amplified by the amplifier 640 , and are fed to the controller 640 . The controller 640 converts the analog signals from the strain gages 680 into digital signals, multiplexes them into a data stream, and outputs the data stream to a modem associated with controller 640 (preferably a radio frequency modem). The modem modulates the data stream for transmission from antenna 645 a . The antenna 645 a transmits the encoded data stream to an antenna 645 b disposed in the interface 615 . The antenna 645 b sends the received data stream to a modem, which demodulates the data signal and outputs it to a joint analyzer controller 655 . Alternatively, the analog signals from the strain gages may be multiplexed and modulated without conversion to digital format. Alternatively, conventional slip rings, an electric swivel coupling, roll rings, or transmitters using fluid metal may be used to transfer data from the shaft 610 to the interface 615 .
[0033] The torque shaft may further include a turns counter 665 , 670 . The turns counter may include a turns gear 665 and a proximity sensor 670 . The turns gear 665 is rotationally coupled to the torque shaft 610 . The proximity sensor 670 is disposed in the interface 615 for sensing movement of the gear 665 . The sensitivity of the gear/sensor 665 , 670 arrangement may be, for example, one-tenth of a turn; one-hundredth of a turn; or one-thousandth of a turn. However, other sensitivities are contemplated. The sensor 670 is adapted to send an output signal to the joint analyzer controller 655 . It is contemplated that a friction wheel/encoder device (see FIG. 4 ), a gear and pinion arrangement, or other suitable gear/sensor arrangements known to person of ordinary skill in the art may be used to measure turns of the torque shaft.
[0034] The controller 655 is adapted to process the data from the strain gages 680 and the proximity sensor 670 to calculate respective torque, longitudinal load, and turns values therefrom. For example, the controller 655 may de-code the data stream from the strain gages 680 , combine that data stream with the turns data, and re-format the data into a usable input (i.e., analog, field bus, or Ethernet) for a make-up computer system 706 (see FIG. 3 ). Using the calculated values, the controller may control operation of the top drive 50 and/or the torque head 40 . The controller 655 may be powered by the power source 660 . The controller 655 may also be connected to a wide area network (WAN) (preferably, the Internet) so that office engineers/technicians may remotely communicate with the controller 655 . Further, a personal digital assistant (PDA) may be connected to the WAN so that engineers/technicians may communicate with the controller 655 from any worldwide location.
[0035] The torque sub 600 is also disclosed in U.S. Patent App. Pub. No. 2007/0251701 filed by Jahn, et al. on Apr. 27, 2007, which application is herein incorporated by reference in its entirety.
[0036] Tubular Makeup System
[0037] FIG. 3 is a block diagram illustrating a tubular make-up system 700 , according to one embodiment of the present invention. The tubular make-up system 700 may include the top drive 50 , torque head 40 , a computer system 706 and torque sub 600 , torque meter 900 , or upper turns counter 905 a (without lower turns counter 905 b ). Whether the tubular make-up system 700 includes the torque sub 600 , torque meter 900 , or the torque head turns counter may depend on factors, such as rig space and cost. During make-up of a tubing assembly 30 , 65 , a computer 716 of the computer system 706 monitors the turns count signals and torque signals 714 from the torque sub 600 and compares the measured values of these signals with predetermined values. If the torque sub 600 or torque meter 900 is not used, the computer 716 may calculate torque and rotation output of the top drive 50 by measuring voltage, current, and/or frequency (if AC top drive) of the power 713 input to the top drive. For example, in a DC top drive, the speed is proportional to the voltage input and the torque is proportional to the current input. Due to internal losses of the top drive, the calculation is less accurate than measurements from the torque sub 600 ; however, the computer 716 may compensate the calculation using predetermined performance data of the top drive 50 or generalized top drive data or the uncompensated calculation may suffice. An analogous calculation may also be made for a hydraulic top drive (i.e., pressure and flow rate).
[0038] Predetermined values may be input to the computer 716 via one or more input devices 718 , such as a keypad. Illustrative predetermined values which may be input, by an operator or otherwise, include a delta torque value 724 , a delta turns value 726 , minimum and maximum turns values 728 and minimum and maximum torque values 730 . During makeup of a tubing assembly, various output may be observed by an operator on output device, such as a display screen, which may be one of a plurality of output devices 720 . The format and content of the displayed output may vary in different embodiments. By way of example, an operator may observe the various predefined values which have been input for a particular tubing connection. Further, the operator may observe graphical information such as a representation of the torque rate curve 500 and the torque rate differential curve 500 a . The plurality of output devices 720 may also include a printer such as a strip chart recorder or a digital printer, or a plotter, such as an x-y plotter, to provide a hard copy output. The plurality of output devices 720 may further include a horn or other audio equipment to alert the operator of significant events occurring during make-up, such as the shoulder condition, the terminal connection position and/or a bad connection.
[0039] Upon the occurrence of a predefined event(s), the computer system 706 may output a dump signal 722 to automatically shut down the top drive unit 100 . For example, dump signal 722 may be issued upon the terminal connection position and/or a bad connection. The comparison of measured turn count values and torque values with respect to predetermined values is performed by one or more functional units of the computer 716 . The functional units may generally be implemented as hardware, software or a combination thereof. By way of illustration of a particular embodiment, the functional units are software. In one embodiment, the functional units include a torque-turns plotter algorithm 732 , a process monitor 734 , a torque rate differential calculator 736 , a smoothing algorithm 738 , a sampler 740 , a comparator 742 , a deflection compensator 752 , and an interlock 749 . It should be understood, however, that although described separately, the functions of one or more functional units may in fact be performed by a single unit, and that separate units are shown and described herein for purposes of clarity and illustration. As such, the functional units 732 - 742 , 749 , and 752 may be considered logical representations, rather than well-defined and individually distinguishable components of software or hardware.
[0040] The frequency with which torque and rotation are measured may be specified by the sampler 740 . The sampler 740 may be configurable, so that an operator may input a desired sampling frequency. The measured torque and rotation values may be stored as a paired set in a buffer area of computer memory. Further, the rate of change of torque with rotation (i.e., a derivative) may be calculated for each paired set of measurements by the torque rate differential calculator 736 . At least two measurements are needed before a rate of change calculation can be made. In one embodiment, the smoothing algorithm 738 operates to smooth the derivative curve (e.g., by way of a running average). These three values (torque, rotation, and rate of change of torque) may then be plotted by the plotter 732 for display on the output device 720 .
[0041] In one embodiment, the rotation value may be corrected to account for system deflections using the deflection compensator 752 . As discussed above, torque is applied to a tubular 30 (e.g., casing) using a top drive 50 . The top drive 50 may experience deflection which is inherently added to the rotation value provided by the turns gear 665 or other turn counting device. Further, a top drive unit 50 will generally apply the torque from the end of the tubular that is distal from the end that is being made. Because the length of the tubular may range from about 20 ft. to about 90 ft., deflection of the tubular may occur and will also be inherently added to the rotation value provided by the turns gear 665 . For the sake of simplicity, these two deflections will collectively be referred to as system deflection. In some instances, the system deflection may cause an incorrect reading of the tubular makeup process, which could result in a damaged connection.
[0042] To compensate for the system deflection, the deflection compensator 752 utilizes a measured torque value to reference a predefined value (or formula) to find (or calculate) the system deflection for the measured torque value. The deflection compensator 652 includes a database of predefined values or a formula derived therefrom for various torque and system deflections. These values (or formula) may be calculated theoretically or measured empirically. Empirical measurement may be accomplished by substituting a rigid member, e.g., a blank tubular, for the tubular and causing the top drive unit 50 to exert a range of torque corresponding to a range that would be exerted on the tubular to properly make-up a connection. The torque and rotation values measured would then be monitored and recorded in a database. The deflection of the tubular may also be added into the system deflection.
[0043] Alternatively, instead of using a blank for testing the top drive, the end of the tubular distal from the top drive unit 50 may simply be locked into a spider. The top drive unit 50 may then be operated across the desired torque range while the resulting torque and rotation values are measured and recorded. The measured rotation value is the rotational deflection of both the top drive unit 50 and the tubular. Alternatively, the deflection compensator 752 may only include a formula or database of torques and deflections for the tubular. The theoretical formula for deflection of the tubular may be pre-programmed into the deflection compensator 752 for a separate calculation of the deflection of the tubular. Theoretical formulas for this deflection may be readily available to a person of ordinary skill in the art. The calculated torsional deflection may then be added to the top drive deflection to calculate the system deflection.
[0044] After the system deflection value is determined from the measured torque value, the deflection compensator 752 then subtracts the system deflection value from the measured rotation value to calculate a corrected rotation value. The three measured values—torque, rotation, and rate of change of torque—are then compared by the comparator 742 , either continuously or at selected rotational positions, with predetermined values. For example, the predetermined values may be minimum and maximum torque values and minimum and maximum turn values.
[0045] Based on the comparison of measured/calculated/corrected values with predefined values, the process monitor 734 determines the occurrence of various events and whether to continue rotation or abort the makeup. In one embodiment, the process monitor 734 includes a thread engagement detection algorithm 744 , a seal detection algorithm 746 and a shoulder detection algorithm 748 . The thread engagement detection algorithm 744 monitors for thread engagement of the two threaded members. Upon detection of thread engagement a first marker is stored. The marker may be quantified, for example, by time, rotation, torque, a derivative of torque or time, or a combination of any such quantifications. During continued rotation, the seal detection algorithm 746 monitors for the seal condition. This may be accomplished by comparing the calculated derivative (rate of change of torque) with a predetermined threshold seal condition value. A second marker indicating the seal condition is stored when the seal condition is detected.
[0046] At this point, the turns value and torque value at the seal condition may be evaluated by the connection evaluator 750 . For example, a determination may be made as to whether the corrected turns value and/or torque value are within specified limits. The specified limits may be predetermined, or based off of a value measured during makeup. If the connection evaluator 750 determines a bad connection, rotation may be terminated. Otherwise rotation continues and the shoulder detection algorithm 748 monitors for shoulder condition. This may be accomplished by comparing the calculated derivative (rate of change of torque) with a predetermined threshold shoulder condition value. When the shoulder condition is detected, a third marker indicating the shoulder condition is stored. The connection evaluator 750 may then determine whether the turns value and torque value at the shoulder condition are acceptable.
[0047] In one embodiment, the connection evaluator 750 determines whether the change in torque and rotation between these second and third markers are within a predetermined acceptable range. If the values, or the change in values, are not acceptable, the connection evaluator 750 indicates a bad connection. If, however, the values/change are/is acceptable, the target calculator 752 calculates a target torque value and/or target turns value. The target value is calculated by adding a predetermined delta value (torque or turns) to a measured reference value(s). The measured reference value may be the measured torque value or turns value corresponding to the detected shoulder condition. In one embodiment, a target torque value and a target turns value are calculated based off of the measured torque value and turns value, respectively, corresponding to the detected shoulder condition.
[0048] Upon continuing rotation, the target detector 754 monitors for the calculated target value(s). Once the target value is reached, rotation is terminated. In the event both a target torque value and a target turns value are used for a given makeup, rotation may continue upon reaching the first target or until reaching the second target, so long as both values (torque and turns) stay within an acceptable range. Alternatively, the deflection compensator 752 may not be activated until after the shoulder condition has been detected.
[0049] Whether a target value is based on torque, turns or a combination, the target values are not predefined, i.e., known in advance of determining that the shoulder condition has been reached. In contrast, the delta torque and delta turns values, which are added to the corresponding torque/turn value as measured when the shoulder condition is reached, are predetermined. In one embodiment, these predetermined values are empirically derived based on the geometry and characteristics of material (e.g., strength) of two threaded members being threaded together. Exemplary embodiments of the tubular makeup system are disclosed in U.S. Provisional Patent Application Ser. No. 60/763,306, filed on Jan. 30, 2006, which application is herein incorporated by reference in its entirety.
[0050] Torque Meter
[0051] FIG. 4 is a side view of a top drive system employing the torque meter 900 . FIG. 4A is an enlargement of a portion of FIG. 4 . FIG. 4B is an enlargement of another portion of FIG. 4 . The torque meter 900 includes upper 905 a and lower 905 b turns counters. The upper turns counter 905 a is located on the torque head 40 . Alternatively, if a crossover or direct connection between the tubular and the quill 910 is used instead of the torque head, then the upper turns counter 905 a may be located below the connection therebetween. Alternatively, the upper turns counter 905 a may be located near an upper longitudinal end of the first tubular 30 . The lower turns counter 915 b is located along the first tubular 30 proximate to the box 65 b . Each turns counter includes a friction wheel 920 , an encoder 915 , and a bracket 925 a,b . The friction wheel 920 of the upper turns counter 905 a is held into contact with the torque head 40 . The friction wheel 920 of the lower turns counter 905 b is held into contact with the first tubular 30 . Each friction wheel is coated with a material, such as a polymer, exhibiting a high coefficient of friction with metal. The frictional contact couples each friction wheel with the rotational movement of outer surfaces of the drive shaft 910 and first tubular 30 , respectively. Each encoder 915 measures the rotation of the respective friction wheel 920 and translates the rotation to an analog signal indicative thereof. Alternatively, a gear and proximity sensor arrangement or a gear and pinion arrangement may be used instead of a friction wheel for the upper 905 a and/or lower 905 b turns counters. In this alternate, for the lower turns counter 905 b , the gear would be split to facilitate mounting on the first tubular 402 .
[0052] These rotational values may be transmitted to the joint make-up system 700 for analysis. Due to the arrangement of the upper 905 a and lower 905 b turns counters, a torsional deflection of the first tubular 402 may be measured. This is found by subtracting the turns measured by the lower turns counter 905 b from the turns measured by the upper turns counter 905 a . By turns measurement, it is meant that the rotational value from each turns counter 905 a,b has been converted to a rotational value of the first tubular 402 . Once the torsional deflection is known a controller or computer 706 may calculate the torque exerted on the first tubular by the top drive 100 from geometry and material properties of the first tubular. If a length of the tubular 402 varies, the length may be measured and input manually (i.e. using a rope scale) or electronically using a position signal from the draw works 105 . The turns signal used for monitoring the make-up process would be that from the bottom turns counter 905 b , since the measurement would not be skewed by torsional deflection of the first tubular 402 .
[0053] Interlock Operation
[0054] FIG. 5 is a flow chart illustrating operation of the interlock 749 , according to another embodiment of the present invention. As discussed above, there is a threaded connection between the torque head 40 /torque sub 600 (if present) and the quill and may also be one or more intermediate connections (hereinafter top drive connections). The interlock 749 may detect a breakout at one of these connections. Typically, the connections are right-hand connections as are most tubulars that the top drive is used to make up. However, to break-out connections, left-hand torque is applied to the tubular 30 which also tends to break-out the top drive connections. Additionally, the interlock 749 may be used to detect break-out of the top drive connections during make-up of left-hand connections, such as expandable tubulars, or any time the top-drive 50 exerts an opposite-hand torque to that of the top-drive connections. Use of the interlock 749 is not limited to top drives equipped with torque heads or spears but may also be used with crossovers or direct connection between the top drive and the tubular.
[0055] At step 5 - 1 , the interlock 749 monitors the output torque of the top drive 50 and compares the output torque to a predetermined or programmed output torque. As discussed above, this act may be performed using the torque sub 600 , torque meter 900 , or calculated from input power 713 . A left-hand direction of the output torque may be indicated by a negative torque value. Examples of the predetermined torque are any left-hand torque and a maximum (minimum if positive convention) breakout torque of the top drive connections. If the monitored torque is less than (assuming negative convention for left hand torque) the predetermined torque, the interlock proceeds to step 5 - 2 of the control logic.
[0056] At step 5 - 2 , the interlock detects any sudden change (i.e., increase for negative convention or decrease for positive convention or absolute value) in the torque value during operation. A sudden increase in torque at the torque head 40 indicates a breakout of either one of the top drive connections or the connection between the tubulars 30 , 65 . The interlock may calculate a derivate of the torque with respect to time or with respect to turns to aid in detecting the sudden increase. A sudden increase in torque may be detected by monitoring the derivative for a change in sign. For example, assuming a negative convention during a breakout operation, the derivative may be a substantially constant negative value until one of the connections breaks. At or near breakout, the derivative will exhibit an abrupt transition to a positive value. Once the breakout is determined, the interlock proceeds to step 5 - 3 .
[0057] At step 5 - 3 , the interlock 749 detects for rotation associated with the sudden change in torque so that the interlock may determine if the breakout is at the connection between the tubulars 30 , 65 or if the breakout is at one of the top drive connections. If the torque sub 600 is being used, the reading from the sensor 670 will allow the interlock to ascertain where the breakout is. If the breakout is between the torque sub 600 and the top drive 50 , then the quill will rotate while the torque sub remains stationary. If the breakout is at the connection between the tubulars 30 , 65 , then the torque sub 600 will rotate with the quill and the first tubular 30 . If the either the torque meter 900 or the power input is used to calculate the output torque, then the interlock 749 may use the upper turns counter 905 a to ascertain where the breakout is. Alternatively or additionally, if the torque meter 900 is used, then the interlock 749 may use the lower turns counter 905 b to determine if the first tubular 30 is rotating. The interlock 749 may calculate a differential of rotation values or a rotational velocity of the torque sub 600 /torque head 40 and compare the differential rotation/rotational velocity to a predetermined number (i.e., zero or near zero) to determine if the torque sub 600 /torque head 40 is rotating.
[0058] If the interlock 749 determines that the breakout is at one of the top drive connections (i.e., the torque head 40 or the torque sub 600 is not rotating), then the interlock proceeds to step 5 - 4 . At step 5 - 4 , the interlock 749 may then sound an audible alarm and/or display a visual signal to the operator to stop rotation of the top drive 50 to prevent back out of the top drive connections. Additionally or alternatively, the interlock 749 may automatically stop the top drive 50 . If the interlock 749 determines that the breakout is at the tubular connection 30 , 65 , then the interlock allows the breakout operation to proceed. The interlock may utilize fuzzy logic in performing the control logic of FIG. 5 .
[0059] In an alternative embodiment (not shown), monitoring output torque of the top drive is not required. This alternative may be performed using the torque sub 600 , torque meter 900 , or upper turns counter 905 a configurations. This alternative may also be used in addition to the logic of FIG. 5 . In this alternative, the interlock may monitor readings/calculations from and calculate a differential between the calculated rotation of the top drive and the sensor 670 or the upper turns counter 905 a . Alternatively, the interlock 749 may calculate rotational velocities of the quill and the torque sub 600 /torque head 40 and calculate a differential between the rotational velocities. If the differential is less than (again using a negative convention) a predetermined number, then the interlock 749 may sound/display an alarm and/or halt operation of the top drive. The predetermined number may be set to account for deflection and/or inaccuracy from the calculated rotation value.
[0060] In a second alternative embodiment applicable to make-up systems 700 using the torque sub 600 or the torque meter 900 , the interlock 749 may calculate a differential between the torque value measured from the torque sub 600 or the calculated torque value from the torque meter 900 and the calculated output torque of the top drive 50 . The interlock 749 may also calculate a turns differential as discussed in the first alternative. The interlock 749 may then compare the two delta values to respective predetermined values and sound an alarm and/or halt operation of the top drive 50 if the two delta values are less than the predetermined values.
[0061] In a third alternative embodiment, a strain gage 785 may be bonded to the swivel housing 605 (including the swivel bracket 605 a ) so that the interlock 749 may monitor performance of the swivel bearings. The bearing performance may be monitored during any operation of the top drive, i.e., making up/breaking out connections or drilling (with drill pipe or casing). Discussion of torque relative to the swivel bearings is done assuming right-hand (positive) torque is being applied as is typical for operation of a top drive 50 . This alternative may be performed in addition to any of the breakout monitoring, discussed above. If the swivel bearings should fail, excessive torque may be transferred from the top drive 50 to the bracket 605 a , thereby causing substantial damage to the bracket 605 a and possibly the swivel 600 as well as creating a hazard on the rig. The strain gage 785 is positioned on the bracket 605 a to provide a signal 712 to the computer 716 indicative of the torque exerted on the swivel housing 605 by the top drive 50 through the swivel bearings. The interlock 749 may receive the signal 712 and calculate the torque exerted on the swivel housing 605 from predetermined structural properties of the swivel housing. The interlock 749 may calculate a differential between the output torque of the top drive 50 (calculated or measured) and the swivel torque.
[0062] If the bearings are functioning properly, this differential should be relatively large as friction in the bearings (and seals) should only transmit a fraction of the top drive torque. If the swivel bearings should start to fail, this differential will begin to decrease. The interlock 749 may detect failure of the swivel bearings by comparing the differential to a predetermined value. Alternatively, the interlock 749 may calculate a derivative of the differential with respect to time or turns and compare the derivative to a predetermined value. Alternatively, the interlock 749 may divide the swivel torque by the top drive torque to create a ratio (or percentage) and compare the ratio to a predetermined ratio. Failure of the bearing would be indicated by ratio greater than the predetermined ratio. The interlock 749 may only monitor swivel performance above a predetermined output torque of the top drive 50 to eliminate false alarms. In any event, if the interlock 749 detects failure of the swivel bearings, then the interlock 749 may sound/display an alarm and/or halt operation of the top drive 50 . Alternatively, the interlock 749 may compare the calculated torque value to a predetermined value (without regard to the top drive torque) to determine failure of the swivel bearings.
[0063] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
|
Embodiments of the present invention generally relate to methods and apparatus for improving top drive operations. In one embodiment a method of ensuring safe operation of a top drive includes operating a top drive, thereby exerting torque on a first tubular to makeup or breakout a first threaded connection between the first tubular and a second tubular. The method further includes monitoring for break-out of a second connection between a quill of the top drive and the first tubular; and stopping operation of the top drive and/or notifying an operator of the top drive if break-out of the second connection is detected.
| 4
|
BACKGROUND OF THE INVENTION
This invention relates to a new and improved green ceramic article which can be fired to produce an improved suppressor for use at elevated temperatures.
Suppressor elements suitable for use in spark plugs must have good mechanical and electrical stability at high temperatures, a wide operating temperature range, uniform resistance value and good suppression of high frequency oscillations associated with spark discharge in ignition systems.
The problem of eliminating radio frequency radiation from the high voltage ignition system of internal combustion engines has been of increasing concern in recent years because such radiation produces interference with the use of radio channels for communication and navigation. This problem has been accentuated by the increasing number of automobiles, boats and aircraft and the simultaneous increase in the use of radio frequency equipment in both communications and navigational equipment.
The typical ignition system for an internal combustion engine includes a set of breaker points, a capacitor, an ignition coil, a spark plug, and connection wires. When the breaker points are closed, a battery causes a current to flow in a primary winding of the ignition coil, thereby establishing a magnetic field about, and storing energy in, a ferrous core in the ignition coil. When the breaker points are opened, the magnetic field collapses and produces a high voltage across a secondary winding of the ignition coil. The high voltage is applied to, and arcs across, a spark gap in the spark plug, greatly decreasing the impedance of the gap. The secondary coil winding and the low impedance spark gap form a resonant circuit which oscillates as the energy stored in the core is dissipated. The oscillations are in the radio frequency spectrum and may cause severe noise and interference in both communications equipment and navigational equipment.
In the past, it has been found that random radio frequency radiation from the ignition system of internal combustion engines may be greatly reduced or eliminated by placing a resistance element in the high voltage ignition circuit for each spark plug. The resistance element may be positioned in the bore of a spark plug insulator, in series with the spark plug center electrode, or may be placed at some other convenient location in the ignition system, such as in a distributor rotor or distributed in the high voltage ignition cables.
Prior art suppressors, other than distributed resistances found in ignition cables, are generally either of a carbon rod type, of a wire wound type, of a sintered resistive rod type or of a resistive mass fired between the glass seals in the center electrode bore through a spark plug insulator. Each of the different types of suppressors has advantages and disadvantages. The carbon capsule suppressor is, for example, relatively inexpensive compared to a wire wound suppressor. The carbon capsule usually consists of carbon or graphite dispersed in a resinous binder. However, when the carbon capsule suppressor is placed in a spark plug and is heated to perhaps 450°F. or more during operation of the internal combustion engine, the carbon tends to oxidize, resulting in an open circuit due to rapidly increasing resistance levels as the carbon oxidizes, until a value of infinity is reached. Vitreous type carbon suppressor elements, formed from clay, talc and a refractory material having carbon distributed therein, have been used extensively. However, it is difficult to prepare such suppressors having uniform resistance values.
Wire wound suppressors do not possess as high a resistance level as carbon resistors because they suppress by inductive impedance rather than by resistance impedance. However, the wire wound suppressor is expensive compared to the carbon resistor and presents problems both in arcing and in connecting terminals to the wire ends. Wire wound suppressors are also bulky and, therefore, difficult to use in smaller size spark plugs.
Suppressor elements suitable for use in an internal combustion engine must withstand severe operating conditions involving pulsating high power loadings. The suppressor element must operate well at temperatures ranging from 200° to greater than 400°F. at 15,000 volts pulsating direct current.
In an attempt to overcome difficulties encountered with the use of carbon, other suppressor composition systems have been suggested. For example, U.S. Pat. Nos. 2,864,773 and 2,969,582 disclose the use of titanate and stano-titanate type materials modified to obtain desired electrical characteristics.
The Radio Manufacturers Association (RMA) and the Society of Automotive Engineers (SAE) have directed efforts toward determining limits for interference from internal combustion engines in communication and navigation equipment. As a result, the SAE has adopted limits for impulsive type interference and has included these limits in a uniform test standard SAE J551b, "Measurement of the Vehicle Radio Interference".
It is known that significant improvements can result in operation of communication and navigation equipment when engine-driven apparatus comply with the limits set forth in SAE J551b. Communications apparatus that operate in the frequency range 20-1000 megahertz which might be susceptible to radio frequency interference are very high frequency (VHF) television, ultra high frequency (UHF) television, frequency modulated (FM) radio, aircraft navigation and communication, amateur radio, telemetry, high frequency (HF) communications, UHF radar, and others.
The testing equipment required for SAE J551b is complex and expensive. However, satisfactory testing results can be obtained by comparing test samples with a wire wound suppressor and a carbon suppressor having known resistance and suppressing properties, and measuring the field intensity per unit band width within a given frequency range.
Manganese oxide and manganese-nickel oxide resistor elements are known in the art. However, such compositions have a relatively high temperature coefficient of resistance, which is undersirable in controlling radio frequency radiation.
SUMMARY OF THE INVENTION
The instant invention is based upon the discovery that a manganese oxide and manganese oxide-nickel matrix can be controlled and modified by means of incorporating strontium and aluminum atoms into the matrix in such a manner as to produce, after firing, a suppressor element having a relatively low negative temperature coefficient of resistance and good suppression characteristics. The manganese oxide and manganese oxide-nickel composition is modified in such a manner that the numerical value of the atom ratio ##EQU3## is maintained in the range 0.1 to 1.5. The atom ratio of strontium to aluminum is from 0.5:1 to 0.95:1. The manganese constitutes from 50 percent to 100 percent of the total number of atoms of manganese and nickel. The temperature coefficient of resistance of the suppressor ranges from -2.8%/°C to -1.3%/°C.
It is therefore an object of the present invention to provide a composition that has, after firing, a low temperature coefficient of resistance.
It is a further object of the present invention to provide a suppressor composition that has a high temperature stability.
It is a still further object of the present invention to provide a suppressor composition that is capable of suppressing unwanted radio frequency radiation in internal combustion engine ignition systems.
Other objects and advantages of the invention will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representation of the curve obtained from the measurement of the temperature coefficient of resistance of a series of manganese and manganese oxide-nickel suppressor elements showing the effect of varying the amounts of strontium, aluminum and nickel in the manganese oxide matrix, such that the ##EQU4## ratio is maintained from 0.1 to 1.5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example I
A series of manganese oxide suppressor compositions, modified with additions of strontium and alumina, was prepared by mixing together the materials listed below and firing to the temperature indicated. Test results obtained are listed in Table I. The compositions can be described as:
(Al.sub.1.sub.-x.sup..sup.+3 Sr.sub.x.sup..sup.+2) (Mn.sub.1.sub.-x.sup..sup.+3 Mn.sub.x.sup..sup.+4) 0.sub.3
where an exchange of electrons between the +3 and +4 ions produces conductivity.
The ratio of Mn atoms to total Sr + Al modifying atoms was maintained at a 1:1 ratio, while the Sr/Al ratio was varied. As illustrated in Table I, experimental results obtained indicated that in order to induce semiconductivity at least 50 percent of the total Sr and Al modifying ions must be Sr.
TABLE I__________________________________________________________________________ Atom RatioMaterial Sample Sample Sample Sample Sample SampleAdded Atom A B C D E F__________________________________________________________________________MnO.sub.2 Mn 63 63 63 63 63 63SrCO.sub.3 Sr 20 36 40 32 40 50Al.sub.2 O.sub.3 Al 43 27 23 34 25 14Sr + Al 1.0 1.0 1.0 1.1 1.1 1.1Mn + NiSintering 2300° 2300° 2300°Temperature to to to(2 Hours) 2400°F 2400°F 2400°F 2400°F 2400°F 2400°FR.sub.25.sub.°C (4V) ∞ 6.5KΩ 15KΩn (%/°C)(± 0.1) -- -1.3 -1.3 -1.6 -1.6 -1.6__________________________________________________________________________
Sample B was compared for suppression of radio frequency interference against a carbon suppressor standard and a wire wound suppressor. Test results are shown in Table II below. Sample B compared favorably with both the carbon and wire wound suppressor; the measured amplitude was below the recommended limit of radiation suggested by SAE standards.
TABLE II______________________________________Sample Amplitude, dB______________________________________Sample B -6Standard Carbon 0Wire Wound -5______________________________________
The resistance at any temperature (from 25° to 250°C) can be expressed by the equation:
R.sub.T = R.sub.25.sub.°C exp[n(T-25°C)].
where R T is the resistance at some temperature T, R 25 .sub.°C is room temperature resistance and n is the temperature coefficient of resistance. For manganese oxide and manganese oxide-nickel suppressors, n (in %/°C) is negative and defined by ##EQU5##
Example II
A series of manganese oxide suppressor compositions, additionally containing nickel oxide, modified with varying amounts of strontium and aluminum atoms, was prepared as described in Example I. Test results are listed in Table III.
TABLE III__________________________________________________________________________ Atom RatioMaterial Metal Sample Sample Sample Sample Sample SampleAdded Atom G H I J K L__________________________________________________________________________MnO.sub.2 Mn 65 63 63 -- -- 63Mn.sub.3 O.sub.4 Mn -- -- -- 63 63 --NiO Ni 20 20 20 20 20 20SrCO.sub.3 Sr 9 32 40 32 40 63Al.sub.2 O.sub.3 Al 3 34 25 34 25 60Sr + Al 0.1 0.8 0.8 0.8 0.8 1.5Mn + NiSinteringTemperature(2 Hours) 2450°F 2400°F 2400°F 2400°F 2400°F 2450°FR.sub.25.sub.°C (4V) -- 170KΩ 30KΩ 150KΩ 30KΩ --n(%/°C) -2.8 -2.3 -1.9 -2.3 -2.0 -1.5__________________________________________________________________________
TABLE IV______________________________________Sample Amplitude, dB______________________________________H -2I -1J -1K -2Standard Carbon 0Wire Wound -5______________________________________
As indicated in Table III and Table IV, the samples had a low temperature coefficient of resistance, and compared favorably with both the standard carbon and wire wound suppressors.
Example III
A further series of manganese-oxide suppressor compositions, additionally containing nickel oxide, modified with varying amounts of strontium and aluminum atoms, was prepared as described in Example I. Test results, to determine the effect of nickel addition upon the temperature coefficient of resistance (n), are listed in Table V.
TABLE V______________________________________Material Metal Sample Sample SampleAdded Atom M N O______________________________________MnO.sub.2 Mn 63 63 63NiO Ni 20 -- 20SrCO.sub.3 Sr 32 32 42Al.sub.2 O.sub.3 Al 31 31 41Sn + Al 0.76 1.00 1.00Mn + NiSintering Tem-perature (2 Hours) 2400°F 2400°F 2400°Fn (%/°C) -2.4 -1.3 -1.8______________________________________
As shown in the data in Table V when the ratio of ##EQU6## and no nickel is present, a minimum value of n is obtained. (Sample N) Addition of nickel atoms increases the value of n, even though the ##EQU7## ratio is maintained at 1. (Sample O)
It is apparent from the discussion of the modifying effect which the strontium atom exerts upon the manganese oxide or manganese oxide-nickel matrix that the strontium can be added in the form other than the carbonate, for example, as strontium oxide. For economic reasons, strontium carbonate is preferred. Firing of the green article converts the nickel present to nickel oxide, thus similar considerations apply to the choice of a nickel-containing compound.
COMPARATIVE PROCEDURE A
For purposes of comparison, but not in accordance with the invention, a series of suppressor compositions of manganese-nickel oxide and manganese-nickel-cobalt oxide not modified by the addition of strontium or aluminum atoms, was prepared and tested. The samples were prepared by sintering the oxides at 2200°F. for a period of 2 hours. Cylindrical samples 0.13 inch in diameter and 0.26 inch in length were tested.
The composition, n and R 25 .sub.°C values for the samples are given in Table VI:
TABLE VI______________________________________Composition of Mn-Ni-Co Oxide semi-conductors by Atomic RatioMaterial Metal Sample Sample Sample SampleAdded Atom P Q R S______________________________________Mn.sub.2 O.sub.3 Mn 63 63 63 63MnO.sub.2 Mn -- -- -- --NiO Ni 10 10 10 10CoO Co -- 1 5 10R.sub.25.sub.°C (0.26") 1.7MΩ 2.4MΩ 2.2MΩ 0.8MΩn (%/°C) -3.14 -3.15 -3.15 -3.04______________________________________
As indicated in Table VI, the R 25 .sub.°C values were all in the megohm range. The resistance decreased sharply as the samples experienced self-heating as indicated by the high temperature coefficient of resistance given in Table VI.
Other samples were prepared using MnO 2 as the source of manganese instead of Mn 2 O 3 . The MnO 2 compositions suffered from excessive cracking during firing at 2200°F. This was attributed to the volume changes that MnO 2 experiences during firing as shown below.
1200°F. ˜1850°F.MnO.sub.2 →Mn.sub.2 O.sub.3 →Mn.sub.3 O.sub.411.5 percent volume increase 7.4 volume decrease
Since the elements in a given chemical group have similar properties, the other members of the Group II chemical group were tested, as substitutes for strontium specifically, a series of manganese oxide-aluminum compositions modified with the oxides of magnesium, calcium and barium, as a substitute for strontium was prepared and tested. The magnesium, calcium and barium-containing compositions did not produce conducting oxides with controllable temperature coefficients of resistance, but produced instead, insulators.
COMPARATIVE PROCEDURE B
It is known in the art as disclosed in U.S. Pat. No. 2,864,773, that titanate and stanno-titanate materials can be modified with Ta.sup. +5 to obtain semiconductor materials having low thermal coefficient of conductivity. Accordingly, manganese oxide and manganese-nickel oxide compositions were modified with Ta.sup. +5 , Ti.sup. +4 and Si.sup. +2 metal ions. Each composition was sintered at 2200°F. for 2 hours. Samples which displayed semiconductivity properties possessed temperature-resistance values similar to those obtained from manganese oxide bodies as described hereinbefore in Comparative Procedure A. As indicated in Table VII, the room temperature resistance (R 25 .sub.°C) values were all in the megohm range, and high values were obtained for the temperature coefficient of resistance (n).
TABLE VII______________________________________Material Sample Sample Sample SampleAdded Atom T U V W______________________________________MnO.sub.2 Mn 63 63 63 63NiO Ni 20 20 20 --SrO Sr -- -- -- 10CeO.sub.2 Ce -- -- -- 3SiO.sub.2 Si -- 10* 10* 10*TiO.sub.2 Ti 10* 10* -- --Ta.sub.2 O.sub.5 Ta -- -- 0.5* --R.sub.25.sub.°C (4V) 10.9MΩ ∞ 40.9MΩ 72.5MΩn (%/°C) -3.3 -- -3.3 -2.7______________________________________ *Given in percent by weight.
A comparison of the test results described in Examples I, II and III with the test results described in Comparative Procedure A and B demonstrates a drastic improvement in the coefficient of resistance of a manganese oxide or manganese oxide-nickel composition when the composition is altered by the addition of aluminum and strontium atoms.
From the testing results given in Tables I, II and III, the following relationship can be demonstrated as to the effect that the stoichiometry of the ##EQU8## ratio has upon the value of n:
Atom Ratio, n(%/°C) Sr + Al Mn + Ni______________________________________Table VI 0.0 -3.2 ± 0.1Table III 0.1 -2.8 ± 0.1Table III 0.8 -2.1 ± 0.2Table I 1.0 -1.3 ± 0.1Table I 1.1 -1.6 ± 0.1Table III 1.5 -1.5 ± 0.1______________________________________
The above relationship is illustrated graphically in FIG. 1, which shows that the temperature coefficient of resistance of manganese oxide and manganese-nickel oxide semiconductor compositions, modified with Sr and Al atoms, can be controlled between about -2.8 and -1.3%/°C. by maintaining the ##EQU9## ratio from 0.1 to 1.5.
|
An improved ceramic article useful after firing as an electrical suppressor element especially suitable for use in spark plugs is disclosed. The suppressor element is an aluminum-manganese oxide composition modified with a strontium compound which optionally may contain a nickel compound. The numerical value of the atom ratio of the article ##EQU1## IS CONTROLLED FROM 0.1 TO 1.5. The strontium/aluminum atom ratio has a value of from 0.5:1 to 0.95:1. The manganese constitutes from 50 percent to 100 percent based upon the total atoms of manganese and nickel present. The temperature coefficient of resistance of the suppressor, defined by ##EQU2## is between about -2.8%/°C and -1.3%/°C.
| 7
|
1. FIELD OF INVENTION
[0001] This invention relates generally to pet leash assembly to transport filled bags of pet waste, specifically required for transportation of animal waste on a leash for proper disposal.
2. STATUS OF PRIOR ART
[0000]
4177909 December 1979 Haskell
March 1985 Jenkins
November 1994 Roe
August 1995 Lindsay
December 1997 Mitchell
March 1998 Conboy
April 1999 Furneaux
February 2000 Carey
July 2002 Starrett
May 2006 Rabello
5560321 October 1996 Hess
Patents Pending:
[0000]
20080179902 Jul. 31, 2008 Bradley Goldizen
20080216767 Sep. 11 2008 Xiano Long Wang
20080137994 Jun. 12, 2008 Urbina Borja
20080101731 May 1, 2008 Sylvia Carlson
200800121 Jan. 24, 2008 Tammy Mauro
Foreign Patents:
[0000]
255507
720914
2504354
2904289
672873
BACK GROUND OF INVENTION
[0023] Today many States and cities have leash laws requiring pets must remain on a Leash in public, at all times. To keep our environment clean and healthy, there are also laws that require pet owners to clean up their pet waste, if the later is not followed, large fines are imposed.
[0024] The art of a solution has been sought after for years, regarding the retrieving and handling of pet waste. Up to date the most widely used way to retrieve pet waste is by hand, with the use of a plastic bag. There seems to be many solutions developed for carrying these empty plastic bags on a leash, however, very few have been developed to transport the filled plastic bags, once retrieved.
[0025] A portion of the pet waste that is actually being collected today in public, in plastic bags, which have no easy way to transport, are being thrown off to the side of the trail or street, thus turning into litter, or the pet owner is just not picking up the waste at all, thus creating an environmental hazard.
[0026] The alternatives for transporting pet waste on a leash today are made of small fabric containers, which are bulky. The problems with such containers are, 1, you are to wrestle a filled bag of waste into a small compartment, thus creating a situation, in which hands are in contact with the pet waste bag, 2, then you are to carry, the filled bag of waste on the leash along with the bulky container in which the pet waste is housed, and 3, a health hazard arises when you are to retrieve the pet waste bag out of the container to dispose of it.
[0027] Hence, all persons owning and walking a pet is in need of a solution to transport filled bags of waste easily, cleanly and effectively to proper disposal. The present invention provides a solution to transport pet waste on a leash, hands free, providing an easy to use, light weight solution that may very well encourage all pet owners who own it, to clean up pet waste and transport it for proper disposal.
SUMMARY OF INVENTION
[0028] In view of the forgoing, the main objective of this invention is for the transportation of filled bags of pet waste, on an apparatus used to walk or restrain a animal. A Significant advantage of a pet leash in accordance with the invention is that it obviates the need to retrieve, transport and dispose of filled bags of waste properly.
[0029] More particularly an object of the invention is to provide the user with an all in one apparatus the above type, that can carry empty plastic bags, keys, cell phone, money that is adapted with an clip mechanism or mechanisms for light weight, non bulky, transportation of filled bags pet waste.
[0030] This invention is directed to satisfy the need for a simple solution to transport filled bags of pet waste efficiently, cleanly, hands free, on a pet leash to ensure proper disposal.
BRIEF DESCRIPTION OF DRAWINGS
[0031] FIG. 1 . A side view of a pet leash assembly embodying the invention
[0032] FIG. 2 . A side view of pet leash assembly embodying the invention in a working state with waste bag attached,
[0033] FIG. 3 . A top view of pet leash assembly
[0034] FIG. 4 . A bottom view pet leash assembly
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] The invention is a pet leash assembly with the inclusion of 4 that can be used to carry animal waste while walking a animal.
[0036] Referring now to FIG. 1 :
an embodiment of the invention is 1 a pet leash: used to restrain or walk an animal, preferably of non fluid material preferably heavy duty as not to break or tear. another embodiment of the invention is 4 preferably a small clip mechanism and or clip mechanisms, preferably opening in a jaws like fashion made preferably from metal in practice however, it may be constructed from plastic or any hard material used in the art, 4 is preferably 1 inch long and preferably ½ inch wide, and can be used to carry pet waste bags, hands free, another embodiment of invention is 3 , preferably a pocket positioned preferably on the underside of pet leash, 3 serves as a housing for 4 to keep 4 out of the way when not in use, 3 is preferably 6″ long and has preferably 6″ closure, preferably a zipper, however in the practice, velcro, snaps, rivets or any other means as to attach to apparatus, another embodiment of the invention 2 , a housing fabricated from preferably non fluid material, housing preferably is preferably 12″ in length, said housing preferably encompasses said leash preferably lengthwise, forming support for holding, said housing is preferably sewn onto 1 however in practice, snaps glue staples Velcro, rivets or any other means may be used to attach preferred housing to pet leash, another embodiment of invention is 5 , preferably used as a storage compartment, preferably for carrying plastic bags and keys, cell phone and or other belongings, 5 is preferably fabricated out of non fluid material preferably strong canvas, nylon of any other materials used in the art. 5 preferably 6″ in length preferably located on the top of housing 2 , storage compartment is preferably sewn onto housing 2 , however in the art velcro, snaps rivets glue, could be used, 5 has preferably a 6 inch closure on the top, preferably a zipper, however in practice, velcro, snaps rivets, glue may be used, 5 is preferably a quarter moon shape, however in practice any other geometric shapes may be used,
[0041] Referring now to FIG. 2 :
6 showing clip mechanism use while transporting pet waste, 7 is showing hand position while in use,
[0043] Referring now to FIG. 3 :
a top view of invention, 8 , is showing compartment 5 as shown in FIG. 1 , compartment is preferably as wide as the size leash being manufactured and 9 showing preferably a zipper closure for easy access to 4 as shown in FIG. 1 ,
[0045] Referring to FIG. 4 :
10 is a bottom view of compartment 3 as shown in FIG. 1 , 11 showing preferably a zipper closure for easy access to 4 as shown in FIG. 1 ,
[0047] Referring now to FIG. 5 ; 12 is showing clip mechanism, preferably sewn into compartment 3 as shown in FIG. 1 , This view shows how clip mechanism is accessed.
[0048] While there has been shown and described a preferred embodiment of the pet leash assembly it will be appreciated that many changes and modifications may be made therein without, however departing from the essential thereof.
|
A pet leash assembly to carry filled bags of pet waste, with an attached clip mechanism or clip mechanisms. The apparatus allows for fast, lightweight attachment of filled bags of pet waste, for transportation on a leash, and easy detachment for proper disposal.
| 0
|
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention relates to a device for the application of fluid materials to a surface of a sheet-form material, with an application roller which has a roller body with an outer surface which when at least partially abutting on the sheet-form material transfers the fluid material to the sheet-form material.
TECHNICAL FIELD
Numerous apparatuses are already known for the application of fluid materials to a surface of a sheet-form material. Each of these apparatuses requires a special adaptation to the respective materials to be applied and to the circumstances as regards the properties of the sheet-form material, processing temperature, speed and the amount of the material to be applied and also the kind of the material to be applied.
In laminating at least two sheet-form materials it is necessary that a defined amount of fluid materials, particularly adhesive, is applied to at least a first layer of the sheet-form material, so that this layer is applied to at least a further layer of a sheet-form material and remains on this at least one layer of the sheet-form material due to a resulting adhesive bond. The sheet-form material can be, for example, very thin polymer foils or carrier layers, which are extremely sensitive to tensions. Furthermore, a further layer can be laminated, for example, onto a layer with visual information. For this, it is necessary that a uniform bonding between the layers is made possible, so that the information can be recognized and examined.
The use of fluid materials, particularly adhesives, which are taken up by an application roller from a supply region and transferred to the sheet-form material, is necessary for the lamination of layers. In this process of applying the fluid material to the sheet-form material, particularly in the case of adhesives, a soiling of the application roller and its bearing regions occurs. The functional ability or the rotation of the application roller can thereby be worsened or even stopped, which can result in an uneven application of the fluid material to the sheet-form material, or an application of the fluid material to the sheet-form material is rendered impossible.
SUMMARY OF THE INVENTION
The invention therefore has as its object to provide an apparatus for the application of fluid materials to the surface of a sheet-form material, which makes possible a uniform application of a set thickness of a film during a very long duration of operation.
This object is attained with a metering doctor to which a pre-metering channel leads for provision of the fluid material and at least partially wets the application roller with fluid material. A flow of a medium directed substantially outward from a longitudinal mid-axis of the application roller is provided at least in a region bordering on the outer surface of the application roller.
By the use of a medium which at least partially flows radially outward in the edge region of the roller body of the application roller, it is made possible that the fluid material, seen in the axial direction, does not leave the outside surface of the roller body at least in the direction of the bearing regions of the application roller, so that a penetration of the fluid material to the bearing regions of the application roller is prevented. By the bounding of the outside surface by means of a fluid medium, a defined application width of the fluid material on the surface of the sheet-form material can be given, which can be adjusted to the requirements for the further processing of the sheet-form material onto a further layer of a sheet-form material, particularly when the sheet-form material is wider than the outside surface of the application roller.
The air flowing out in the edge region of the roller body of the application roller forms a seal of the bearing region, which furthermore makes it possible for the application roller to be used both for a so-called flying coating, in which the application roller works solely against a sheet tension of the sheet-form material, and also for a coating with the use of a counterpressure roller.
According to an advantageous embodiment of the invention, it is provided that at least one axial bore is provided at least at one end of the application roller, and cross bores branch off therefrom, preferably in the edge region of the outside surface. The medium, preferably under pressure, can thereby be supplied in a simple manner to the edge region of the outside surface, so that a lateral sealing of the application roller relative to the respective bearing is made possible.
According to a further advantageous embodiment of the invention, it is provided that a receiving member is provided at each end of the roller body and forms with the edge region of the roller body a gap leading outward. Sealing of the bearing regions and limitation of the outside surface of the roller body as application surface is thus made possible. It is advantageously provided that the receiving member at least partially covers the cross bore. A guide channel or gap for the medium can thus be formed by a receiving member in a simple manner, and is constituted as far as the outside surface of the roller body.
According to a further advantageous embodiment of the invention, it is provided that the receiving member is constituted as a bearing and has a bearing section for receiving the application roller. Thereby on the one hand, the number of components is reduced, and also, on the other hand, simple and rapid mounting is made possible.
According to a further advantageous embodiment of the invention, it is provided that the end face of the roller body and the surface of the receiving member arranged complementary thereto form a gap which is directed at right angles to the longitudinal axis of the application roller or at an angle in the direction of the edge region of the sheet-form material or of the bearing regions. A fluid material possibly overflowing over the edge region of the outside surface of the roller body can thereby be guided away laterally outward, without the set coating thickness of the fluid material on the sheet-form material being adversely affected.
According to a further advantageous embodiment of the invention, it is provided that the gap between the end face of the roller body and the receiving member is adjustable. The sealing can thereby take into account the respective case of application and the sensitivities of the fluid material and of the sheet-form materials. The flow speed of the medium which flows outward through the gap can advantageously be likewise adjustable.
According to a further advantageous embodiment of the invention, it is provided that a UV crosslinking-active adhesive is provided. In particular, this embodiment is of particular advantage with these adhesives which immediately harden or polymerize when subjected to shear.
According to a further advantageous embodiment of the invention, it is provided that compressed air us used as the medium. A cost-favorable embodiment can thereby be given, since the surrounding air can be compressed and used. It can alternatively be provided that special gases or liquid media or the like are used in order to effect a sealing of the bearing regions.
According to a further advantageous embodiment of the invention, it is provided that the application roller is received by adjustable bearings. It is thereby made possible for the amount of the fluid material taken up from a metering region of the application roller to be adjustable. The bearings can also serve as an additional possibility of adjustment to the metering doctor. Furthermore, changes due to the use of the application roller and possibly of the bearings can be adjusted for.
According to a further advantageous embodiment of the invention, it is provided that the rotation speed of the application roller is equal to or smaller than the sheet speed of the sheet-form material. Thereby a more uniform and thinner film of a fluid material can be applied. In this mode of operation, it can advantageously be provided that the sheet-form material abuts the application roller under tension, which can be adjusted by means of a guide roller before and after the application roller in the sheet forwarding direction.
BRIEF DESCRIPTION OF THE DRAWINGS
A particularly preferred embodiment of the invention is shown in the following description and the accompanying drawings, in which:
FIG. 1 shows a schematic side view of the apparatus according to the invention;
FIG. 2 shows a schematic enlarged partial view, partially in cross section, of the apparatus according to the invention according to FIG. 1;
FIG. 3 shows a schematic enlarged sectional diagram of a top plan view according to FIG. 2;
FIG. 4 shows a schematic detail diagram of an application roller and its bearing arrangement;
FIG. 5 shows a detail view of the application roller in cross section; and
FIG. 6 shows an excerpt from a schematic enlarged side view of the apparatus according to FIG. 1 in an alternative mode of operation for the application of the fluid material to a surface of the sheet-form material.
DETAILED DESCRIPTION OF THE INVENTION
A side view of an apparatus 11 for the application of a fluid material to a surface of a sheet-form material 12 is shown in FIG. 1 . The material 12 is drawn from a supply roll 13 and guided over guide rollers 16 , 17 , 18 to an application roller 19 for applying the fluid material to the sheet-form material 12 .
The sheet-form material 12 coated with fluid material is deflected by means of a transport roller 21 and supplied to a foil or a film 23 , in order to form a composite 24 . The foil 23 is forwarded by a roller 26 to the apparatus 11 , guide rollers 27 , 28 being provided before and after the apparatus 11 and causing the foil 23 to wrap around the roller 26 .
FIG. 1 shows, for example, a processing station in a plant consisting of plural stations. The operational process described hereinafter, in which the apparatus 11 undertakes an operational step, represents a case of application for this embodiment example.
For the production of documents which are secure against forgery, a photopolymer film with holograms is for example used. These photopolymer foils are delivered with protective layers on both sides. For further processing into a document which is secure against forgery, it is necessary for the protective layers to be removed and for subsequent carrier layers to be applied. In a first operation cycle, a delaminating apparatus (not shown) which removes the protective layer can be provided, for example on the roller 26 . A carrier layer is then applied as a sheet-form material 12 to the photopolymer foil by the apparatus 11 according to the invention. A hardening device is provided following the apparatus 11 and produces a composite 24 between the applied carrier layer and the photopolymer foil, a UV crosslinking-active adhesive being provided, preferably as a fluid material. In a second operating cycle, which follows the first operation cycle just described, the process can be repeated for the second side. Because of the high processing speeds and quality requirements, it is necessary that the carrier layer has a fluid material applied to one surface, uniformly and with constant film thickness, so that in the further processing a bubble-free and continuously crosslinked composite due to the adhesive results between the applied carrier layer and the photopolymer film.
The apparatus 11 for applying fluid materials to the surface of a sheet-form material 12 can be used for further cases of application which are similar to, or deviate from, the case of application described hereinabove. Here foils a few micrometers thin, or also thick foils, of plastic or other materials, can be likewise treated and processed.
A fluid material is stored in a dispenser 31 . When a UV crosslinking-active adhesive is processed, a light-protected dispenser 31 is preferably used. The fluid material is supplied from this dispenser 31 by static pressure by means of a housing section 32 to a pre-metering channel 33 of an application head 34 . This is shown in detail in a partial sectional view of the apparatus 11 according to FIG. 2 . The fluid material is supplied via the pre-metering channel 33 to a metering doctor 36 , which is preferably constituted as a metering bar. This metering doctor 36 is adjustable by means of a setting mechanism 37 so that the transverse profile is thereby adjustable along the metering doctor 36 . The metering doctor 36 is furthermore rotatably mounted. In a position of a break-off edge facing toward the application roller 19 as shown in the drawing, the gap is zero. The size of the gap can be adjusted with an anticlockwise rotation of the metering doctor 36 , the gap size increasing with an increasing degree of rotation. The amount of the fluid material to be taken up by the application roller 19 can thereby be determined. The metering doctor 36 is provided with metering pockets 40 extending at least over the length of the outside surface 59 of the roller body 58 . The metering pockets could be provided in they form of a recess. The application roller 19 is provided in an upper section of the application head 34 , a segment region 38 being arranged outside the application head 34 . The sheet-form material 12 , which is constituted as a carrier layer according to the embodiment example described above, is guided past this segment region 38 which stands out with respect to the application head 34 . The guide roller 18 and the transport roller 2 I are positioned with respect to the application roller 19 so that the sheet-form material 12 abuts the application roller 19 with at least slight tension. The transport roller 2 I can be adjusted in its position with respect to the application roller 19 by means of an adjusting mechanism 39 shown in detail in FIG. 6 . The arrangement with respect to the roller 26 , also respectively the distance or pressure, can likewise be adjusted by means of this adjusting mechanism 39 .
The apparatus 11 can be mounted on a housing of the equipment by means of the elements identified with the reference numeral 41 . The housing section 32 and also the application roller 19 and transport roller 21 connected to it can be moved away from the roller 26 in a simple and rapid manner by means of two shafts 42 (FIG. 2) projecting into the housing section 32 , in order to clean or newly insert the parts, or to feed in new sheet-form material.
A schematic top plan view according to FIG. 2 is shown in partial cross section in FIG. 3 . The roller 21 is constituted wider than the roller 26 for the application case described by way of example. The relationships with respect to the width of the rollers 21 and 26 and also their diameter can be selected specifically for an application. This likewise holds for the relationships of the application roller 19 and of the metering doctor 36 .
The application roller 19 is shown in detail in FIG. 4 . This application roller 19 is rotatably driven. For example, a drive shaft 43 is provided which engages a coupling 44 which is constituted as a roller-mounted shaft. A spigot connection 45 is provided on the end remote from the drive shaft 43 , and transmits the rotation of the drive shaft 43 to the application roller 19 . For this purpose, a U-shaped recess is provided on a connecting piece 46 of the application roller 19 , with a bolt 47 engaging in it and equalizing axial tolerances between the coupling 44 and the application roller 19 .
The application roller 19 , shown in complete cross section in FIG. 5, has a left-hand and a right-hand bearing region 48 , 49 . These shaft sections are of crowned form and are rotatably mounted in a receiving member 51 , 52 which can be installed on the housing section 32 . The crowned form can provide an axial compensation between the left and right receiving members. Even with a small displacement of the mutually opposite receiving bores of the holding elements, a smooth-running rotation of the roller without jamming can be given. The application roller 19 is constituted as a hollow shaft and has a through bore 53 situated in the longitudinal mid-axis 55 and connected on one side to two axial bores 54 . In the region of the bearing region 49 , the through bore 53 is closed, sealed to medium, by a threaded pin 56 or the like. The application roller 19 has a roller body 58 with an outside surface 59 by means of which the fluid material is transferred to a surface of the sheet-form material 12 . End faces 61 , 62 are provided in the transition region between the bearing regions 48 , 49 and the roller body 58 , and form with the receiving members 51 , 52 a gap 63 . Complementary sections 66 , 67 of the receiving member 51 , 52 are provided in the region of the end faces 61 , 62 , and extend over the whole periphery.
In the housing section 32 , a counter-bearing 69 is provided at the end of the application roller 19 opposite the drive shaft 43 , making a supply of the medium possible via connections 71 into the axial bores 54 . The medium, preferably under pressure, reaches the through bore 53 via the axial bores, and from there passes outward via cross bores 82 , 83 branching therefrom. The medium is deflected by the receiving member 51 , 52 covering the openings 84 of the cross bores 82 , 83 , and is conducted outward by means of the gap 63 . A leakproof or nearly sealing connection is produced by the bearing regions 48 , 49 and the receiving members 51 , 52 , so that medium emerging from the cross bores 82 , 83 is positively guided outward by the gap 63 .
In a preferred embodiment of the invention, it is provided that air is used as the medium, and is preferably conducted outward under pressure through the gap 63 . Likewise, gaseous, liquid, or gel-form media or the like can be used, depending on the case of application.
Sealing-off of the bearing regions 48 , 49 can be attained by blowing air in, the air flowing at least partially radially outward through the gap 63 . This is particularly advantageous with the use of UV crosslinking-active adhesives, which would harden in a short time when exposed to shear stress, as is the case when the adhesive enters the bearing regions 48 , 49 . Stoppage of the application roller or impairment of its operation can thus be counteracted.
The gap 63 is arranged at an angle due to the side surfaces 61 , 62 and the complementary sections 66 , 67 of the receiving members 51 , 52 , so that the direction of blowing out faces outward with respect to the outer surface 59 . The fluid material coming out over the edge region of the outer surface 59 can thereby be blown off, so that this does not accumulate in the region of the gap 63 .
The design of the gap 63 , as regards width and also direction, can take place optionally; the alignment in FIG. 4 is solely by way of example. The gap 63 can be constituted constant or nozzle-shaped toward the outer surface 59 , so that a kind of venturi effect can arise in the outermost edge region between the outer surface 59 of the roller body 58 and the sections 66 and 67 of the receiving members 51 , 52 . It can furthermore be provided that instead of a complete, radial outflow of the medium, an at least partial and/or swirled outflow is provided. It can furthermore be provided that the constitution of the gap 63 is provided by inserts which can be installed on the end faces 61 , 62 and communicate with the receiving portions 51 , 52 . It can likewise be provided that the receiving members 51 , 52 have interfaces to receive inserts, which are interchangeable. The size, the kind, and also the length of the gap can be selectively varied and adapted specifically to the application in dependence on the case of application. This can be made possible, for example, by ring segments which can be fixed on and interchanged. The application roller 19 furthermore has an adjustable mounting, which makes it possible for both an adjustment as regards the axial spacing from the metering doctor 36 and also an axially parallel adjustment.
The application roller 19 is made of a material which is resistant to the fluid material. For example, stainless steel or bronze or the like can be provided. The structure or surface of the outer surface 59 can be implemented specifically for the application. The use of compressed air for sealing the gap 63 between the outer surface 59 of the application roller 19 and a receiving member 51 , 52 adjoining thereto can for example begin at 0.1 bar and rise to one or more bar.
In the case described hereinabove of use of the embodiment example, the width of the outer surface 59 is constituted smaller than the width of the strip material 12 . An overflow of the fluid material at the side regions of the sheet 12 of material can be trapped by this itself, so that clean processing is made possible. The sheet-form material 12 applied to the foil 23 has, as a composite 24 in the end state, a sheet width which is smaller than the width of the outer surface 59 , so that a composite 24 is created which has a bond completely over its width.
FIG. 6 shows an adjusting mechanism by means of which the position of the transport roller 61 can be adjusted relative to the housing section 32 . A wedge 92 is moved up and down in a slot by means of an adjusting screw 91 , and is connected to a spring-loaded bolt 93 . The bolt 93 can be inserted to a greater or lesser extent into the housing section 32 by changing the wedge position. The position of the transport roller 21 relative to the application roller 19 and to the roller 26 can thereby be adjusted, as is shown by dashed lines and as this reproduces the position according to FIGS. 1 and 2. With this arrangement, by means of the sheet tension, a more or less heavy abutment of the sheet-form material 12 on the application roller 19 is attained. A more or less strong sheet tension can be produced, in dependence on the strength of the sheet-form material 12 . The application roller 19 has a speed of rotation which is equal to, or smaller than, the sheet speed of the sheet-form material 12 . An application against the sheet tension can thereby take place, so that a so-called flying coating is achieved.
It can alternatively be provided that the transport roller 21 is arranged in a position which abuts on the application roller 19 , as shown in FIG. 6 . The pressing pressure of the roller 21 can by adjustable relative to the application roller 19 by means of the adjustment mechanism 39 . The position of the transport roller 21 relative to the roller 26 can also be set at the same time. The adjustment mechanism 39 has a bearing element 94 by means of which the two above-described positions of the transport roller 21 can be set.
|
The invention relates to a device for the application of fluid materials to a surface of a sheet-form material, comprising an application roller, with a roller body and a jacket surface, which, by means of at least partial contact with the sheet-form material, transfers the fluid materials leading to the sheet-form material. The invention further comprises an application doctor blade, with a pre-dosing channel for the supply of fluid materials leading thereto and which at least partly coats the application roller with fluid material. A flow of a medium is provided in at least one region adjacent to the jacket surface, which is directed from the longitudinal mid-axis of the application roller to the outside.
| 8
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to surgical instruments, and more particularly relates to laryngoscopes having opposed blades on distal end thereof.
2. Description of the Prior Art
In anesthesiology, the laryngoscope is used for endotracheal intubation. A rubber or plastic tube is introduced through the larynx into the trachea under direct or indirect optical control.
Earlier laryngoscopes, such as the MacIntosh or Foregger have only one blade. The blade may be strait or curved and is fixedly secured to a hollow handle which houses the batteries. A lamp for providing light for the direct laryngoscopy is mounted on the blade. No optical system was provided.
These earlier laryngoscopes can be introduced orally and used properly only if the patient's mouth is fully opened. If the patient's mouth is fully opened, then the sole blade can slide from the teeth and tongue to the pharynx, pulling or pushing the epiglottis and thus expose the entrance of the larynx.
Intubation is difficult or impossible for those patients with abnormalities, whose mouth could not be fully opened.
In recent times a trial was made to produce laryngoscopes with optical systems to be used in difficult intubations. These newer instruments are not very practical and are not a real progress in anesthesiology.
______________________________________Laryngoscopes and similar instruments forendotracheal intubation patented earlier:Inventor Patent No. Year______________________________________F. Haslinger (U.S.A.) 1,568,732 1926D. T. Atkinson (U.S.A.) 1,607,788 1926A. S. Pogosyan (U.S.S.R.) 898,849/31-16 1964H. J. Zukowski (U.S.A.) 3,677,262 1972H. Feldbarg (U.S.A.) 3,754,554 1973L. Lepelletier (France) 2,361,855 1976J. A. Moses (U.S.A.) 4,114,609 1977J. R. Bullard (U.S.A.) 4,086,919 1978K. Storz (U.S.A.) 4,294,235 1981______________________________________
SUMMARY OF THE INVENTION
The deficiencies of the existing laryngoscopes are overcome by a laryngoscope having a hollow body terminating in a pair of opposed blades. At least one of the blades is pivotal about an axis so that the blades may assume a closed beak position or an opened beak position or, of course, any position there in between. When the opposed blades are in the closed beak position, the laryngoscope may be introduced into the patient's mouth that is only minimally opened. After the introduction, the distal end of the blades are moved apart into the open beak position without the necessity to further open the patient's mouth. Preferably, the movable blades pivot about their axes thereby pressing against the base of the tongue and the soft palate creating a large space where all details of larynx could be observed without obstruction even in major malformations. Disposed between the blades and extending from the elongate hollow body of the laryngoscope, are a tube introducer, a light conducting system and an optical system. The larynx is observed through an objective disposed at the distal end of the optical system.
It is therefore seen to be an important object of the invention to provide a laryngoscope for use with patients with anomalies of the jaws, tongue, larynx or neck, or where the mouth could not be opened fully or where the viewing and reaching of the larynx is difficult or impossible.
Another object of the invention is to provide a laryngoscope having at least one light conducting means for illuminating the larynx during the intubation procedure.
Still another object is to provide an endotracheal tube riding on a flexible and steerable tube introducing member that is fixed in the steering mechanism in the proximal end of the handle of the laryngoscope. The introducing member is located in its hollow tube of the handle and disposed between the opposite blades of the laryngoscope on its distal end.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention will become apparent as the following description proceeds, taken in conjunction with the accompanying drawings in which:
FIG. 1 is a side plan,
FIG. 2 is a side plan showing the disconnected upper part of the laryngoscope,
FIG. 3 is showing the side plan of the disconnected lower part of the laryngoscope,
FIG. 4 is showing the side plan of the laryngoscope with dilated blades and extended and flexed introducer,
FIG. 5 is a plan of the longitudinal view from the proximal end of the laryngoscope,
FIG. 6 is the side plan, partially cut away view of one embodiment illustrative of the invention,
FIG. 7 is the frontal plan of the laryngoscope,
FIG. 8 is showing the introducer and its steering and moving mechanism together with the endotracheal tube,
FIG. 9 is the frontal plan showing the details between the blades in open position,
FIG. 10 is the frontal plan of the connector between the endotracheal tube and the Y-piece of the anesthesia machine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an illustrative embodiment of the laryngoscope. It comprises an elongate hollow laryngoscope body 10, two blades, inferior 14 and superior 16. The blades are forming a right angle to the body of the laryngoscope. A lever causes the movable blades 14 and 16 to pivot about the axes 18 and 19. As the distance between the lever 20 and the laryngoscope body 10 is narrowed, the distance between the free ends of the blades 14 and 16 is increased. The hollow laryngoscope body consists of two tubes, the anterior 21 is the place for the batteries, the posterior 22 is the receptacle for the introducer 23 and the endotracheal tube 24. Also contained within the anterior tube 21 are the light emitting source and light conducting system with the optical fibres for illuminating the larynx region. The optical system, generally designated 26, is positioned in lower, distal portion of the laryngoscope body 10, parallel to the blades 14 and 16 and perpendicular to the body 10. It has a system of lenses for forming an image on the ocular of the optical system 26 so that the physician can observe the target larynx and the progress of the introducer 23 and the endotracheal tube 24 into the trachea during the intubating performance.
If the patient can fully open his or her mouth, and no major anomalies of the jaws, pharynx, tongue, neck and larynx are present, the laryngoscopes conceived earlier are usually adequate because the physician can observe the larynx directly. Should this for many reasons be not possible, the new laryngoscope could be the perfect tool for a difficult intubation. It has united the good viewing, illumination, space creating and tube steering for a successful placement of the tube 24 into the trachea during the intubation performance.
The introducer 23 and its lever 25 are basically constructed like the conventional flexible bronchoscope. By moving the lever 25 forward, pivoting on its axis, the tip of the introducer 23 bends down and vice versa, when the lever 25 is moved backward the tip of the introducer 23 bends up. By turning the proximal end of the tube 28 left or right, the tip of the introducer follows left or right. By pushing or pulling the proximal end of the tube 28 the introducer 23 moves along and inside the posterior tube 28 and 22, forward or backward. Thus, any location of the entrance to the larynx could be reached.
Technically the bending of the tip of the introducer 23 as well as in conventional bronchoscopes, is achieved by moving the lever 25 pivotally on its axis. This action is transferred over a wheel to its connections with two wires located and embeded each in a longitudinal half of the plastic, flexible body of the introducer 23. These wires are freely gliding in the body of the introducer except on its tip where the wires are connected and fixed. If one wire is pulled and the other pushed with the help od the lever 25 and its wheel, the tip of the introducer 23 is bending.
An elongate slot 31 is formed in the laryngoscope body 10 to allow the movement of the endotracheal tube connector 30 and its protrusion 29 together with the tube 24 on the introducer 23 into the trachea. Thus, it is seen that a total of three levers must be manipulated by the physician to perform the intubation procedure.
The intubation is performed with the new laryngoscope as follows: First, the laryngoscope body 10 is held with the left hand and the laryngoscope blades 14 and 16 in "closed beak" position are introduced into the mouth of the patient and, reaching the right position in the valecula, the left hand holding the laryngoscope body 10 moves the lever 20. This action opens the "beak", creating a free space in the pharynx and the larynx could be easily observed with the optical system 26 and good illumination with the system 27. The right hand is steering the introducer 23 by changing the direction of its tip with the lever 25. Simultaneously the right hand is holding the upper end of the posterior tube 28 pushing it downward. This action brings the telescopic part of the posterior tube 28 into the distal part 22, and the introducer 23, with the endotracheal tube 24 riding on it, down and between the open blades 14 and 16 into the larynx. The right hand then pushes the tube connector 30, holding the protrusion 29, along the slot 31. With this movement the endotracheal tube 24 is brought deeper to its optimal position. The left hand is releasing then the lever 20 and the "beak" is almost closed. The left hand pulls then the laryngoscope body 10 and takes the blades 14 and 16 out of the mouth. In the same time the right hand is holding the endotracheal tube 24 in place, by holding the protrusion 29 of the tube connector 30.
A bias mechanism,such as a spring (not shown) is employed to keep the laryngoscope blades 14 and 16 in the closed "beak" position when the lever 20 is not moved. The movement of the lever 20 is transferred to a rack 33 and pinions 34 and 35 and also to the both blades 14 and 16 rotating on axes 18 and 19. Although these mechanical means have been described, it is understood that electrical or pneumatical means could also be employed.
FIG. 2 represents the detached upper part of the laryngoscope body 10 comprising the anterior tube 21 as housing for the batteries and the posterior tube 22 as housing for the introducer 23 and its steering mechanism 25. As the upper part of the laryngoscope body 10 is detached from the lower part of the laryngoscope body 13, the connecting rail 36 and the arresting knob 32 become visible.
FIG. 3 represents the detached lower part of the laryngoscope body 10 generally designated 13, comprising the optical system 26 and the blades 14 and 16 as well as the lever 20 and its mechanism for the movement of the blades 14 and 16. This detachment is necessary for it makes possible to sterilise the contaminated part of the laryngoscope. The detachment makes also possible to use different sizes of the blades 14 and 16 if necessary.
FIG. 4 represents the same lateral view of the laryngoscope as on FIG. 1 but with the lever 20 moved to the body of the laryngoscope 10 and, as the result of this movement the separation of the distal ends of the blades 14 and 16. The telescopic part of the posterior tube 28 is moved into the body of the laryngoscope 10, described as the posterior tube 22. The movement of the telescopic part of the posterior tube 28 into the fixed tube 22 slides the introducer 23 between the blades 14 and 16.
FIG. 5 is the view of the laryngoscope from its proximal end, showing the steering mechanism 25 of the introducer 23, the protrusion lever 29 of the endotracheal tube connector 30, the lever 20 for moving the blades 14 and 16, and the upper blade 16 as well as the optical system 26.
FIG. 6 shows in detail how the movement of the lever 20 is transferred to the axes 18 and 19 and to the blades 14 and 16 over the rack 33 and pinions 34 and 35.
FIG. 7 represents the frontal view of the laryngoscope with the extended telescopic part 28 out of the posterior tube (not visible), the protruding lever 29, the steering mechanism 25 of the introducer 23, the anterior tube 21 and the lever 20. On the lower part of the laryngoscope the closed blades 14 and 16 are visible, as well as the ocular part of the optical system 26.
FIG. 8 represents the introducer 23 and its steering mechanism 25 taken out of the posterior tube 22 of the laryngoscope body 10. This detachment makes the cleaning and sterilisation of the introducer 23 possible. Also visible is the protrusion 29 and, in phantom lines, the endotracheal tube connector 30 with the endotracheal tube 24.
FIG. 9 is showing the frontal view of the lower part of the laryngoscope in detail. By open "beak" and its blades 14 and 16 apart, visible are the distal end of the optical system 26 and its objective, the light conducting system 27 and the distal end of the introducer 23 with the endotracheal tube 24. Further visible are the tip of the rack 33 and pinions 34 and 35 fixed on their axes on the left side of the laryngoscope body only.
FIG. 10 is showing the tube connector 30 and its protrusion lever 29 narrow enough to bypass the axes 18 and 19.
Although the particular embodiments of the invention have been shown and described in full here, there is no intention to thereby limit the invention to the details of such embodiments. On the contrary, the intention is to cover all modifications, alternatives, embodiments, usages and equivalents of the subject invention as fall within the spirit and scope of the invention, specification and the appended claims.
|
A laryngoscope for use in difficult intubation due to malformation of the jaws, tongue, pharynx, larynx or neck as a result of trauma, edema, inflammation or congenital anomalies. An elongate hollow body terminates in a pair of opposed blades perpendicular to the said hollow body being pivotal on two axes. The endotracheal tube used for the intubation rides within the hollow tube on the introducing means disposed in the cavity of the said hollow body. Light conducting means illuminate the larynx and optical means are provided for inspecting the larynx during the intubation procedure.
| 0
|
This application is a continuation-in-part of U.S. patent application Ser. No. 901,998 filed Jun. 22, 1992, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an adjusting shim used in a valve operating mechanism for an internal combustion engine.
b 2. Description of the Prior Art
FIG. 3 is a longitudinal section of a valve operating mechanism for an engine. Referring to FIG. 3, a reference numeral 1 denotes a cylinder head of an engine, 2 a cam, 3 a valve lifter, 4 an adjusting shim, 5 an in take and exhaust valve, 6 a valve seat and 7 a valve spring. In the valve operating mechanism shown in FIG. 3, the valve lifter 3 is driven by the cam 2, and the displacement of the cam 2 is transmitted to the intake and exhaust valve 5. As may be understood from FIG. 3, an adjusting shim 4 is disposed between the valve lifter 3 and cam 2. A longitudinal section of the adjusting shim 4 is shown in FIG. 1. The adjusting shim 4 is used to regulate a valve clearance. Although a conventional adjusting shim 4 consists usually of a metal, there is an adjusting shim formed out of a ceramic material for the purpose of reducing the weight thereof and improving the wear resistance thereof.
However, even when the weight of a ceramic adjusting shim is reduced, a decrease in a power loss caused thereby is not substantially recognized in practice since the percentage of the inertial weight of the adjusting shim with respect to the whole inertial weight of the valve operating system is extremely small. Moreover, the offensiveness of the shim with respect to the parts with which the shim contacts, i.e., the cam 2 and valve lifter 3 shown in FIG. 3 increases, so that these two parts wear greatly.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a ceramic adjusting shim having a smooth surface in which the above-mentioned problems are eliminated.
According to the present invention, there is provided a ceramic adjusting shim comprising a ceramic material the surface roughness of which is not more than 2.0 μm in ten-point average roughness (Rz).
As the ceramic material for the ceramic adjusting shim, silicon nitride is mainly used. The surface roughness of the adjusting shim is preferably not more than 0.8 μm and more preferably not more than 0.2 μm, in ten-point average roughness (Rz).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of an adjusting shim.
FIG. 2 is a longitudinal section of an adjusting shim and a valve lifter.
FIG. 3 is a longitudinal section of a valve operating mechanism for an engine.
FIG. 4 is a longitudinal section of an apparatus for testing a product according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be now described in detail hereinbelow.
When a ceramic adjusting shim having a smooth surface is used, a frictional loss occurring between the cam and the ceramic adjusting shim can be reduced, so that a power loss of the internal combustion engine can be minimized. Moreover, the offensiveness of the ceramic adjusting shim with respect to the cam 2 and valve lifter 3 shown in FIG. 3 decreases, and the abrasion of these two parts can therefore be reduced.
In this case, the roughness of the surface (designated by a reference numeral 8 in FIG. 1), which the cam contacts of the ceramic adjusting shim is not more than 2.0 μm in ten-point average roughness (Rz), and a torque loss caused thereby becomes smaller than that in a case where a conventional metal adjusting shim is used. When the ten-point average roughness (Rz) is up to 0.2 μm, a torque loss decreases in accordance with a decrease in the surface roughness. In a region in which the ten-point average roughness (Rz) of the contact surface is less than 0.2 μm, a torque loss caused thereby is substantially equal to that in a case where the ten-point average roughness is 0.2 μm.
In a region in which the roughness of the surfaces (designated by reference numerals 9 and 10 in FIG. 1), which the valve lifter contacts, of the ceramic adjusting shim is not more than 0.8 μm in ten-point average roughness, an abrasion loss of the valve lifter decreases sharply in accordance with a decrease in the surface roughness of the ceramic adjusting shim, and, in a region in which the surface roughness of the same shim is less than 0.2 μm, and abrasion loss of the valve lifter becomes substantially constant.
On the other hand, forming a shim having a surface roughness of less than 0.05 μm is known to be extremely expensive and time consuming due to the inefficient grinding process necessary to obtain such a small surface roughness. The discovery that, with ceramic adjusting shims, approximately the same results will be achieved with a shim having a surface roughness of 0.2 μm and one which has a surface roughness of 0.05 μm, obviates the necessity of taking the additional manufacturing steps to form a shim having extremely smooth surfaces. Further, it has been found that, surprisingly, when shims having an extremely small surface roughness are used, and actual increase in power consumption (an increase in power loss) is observed.
The present invention will now be described concretely on the basis of its embodiments.
EXAMPLE 1
The same adjusting shims as shown in FIG. 1 were produced out of a silicon nitride ceramic sintered body having a relative density of not less than 98%. The surface, which a cam contacts. i.e. the surface designated by a reference numeral 8 shown in FIG. 1, of each of the adjusting shims was finished under various conditions by a diamond wheel to set the roughness of the surfaces of these adjusting shims thus produced was subjected to the evaluation of power loss with respect to the power consumption of a motor rotated at a predetermined number of revolutions per minute (2000 RPM and 4000 RPM in terms of number of revolutions per minute of engine), by using a motoring system shown in FIG. 4 and simulating an over head camshaft type valve operating mechanism. Table 1 shows the results of the above with the results of similar evaluation of power loss caused by conventional steel adjusting shims which constitute comparative examples.
TABLE 1______________________________________Material Surface roughness Power consumptionfor adjust- Rz of contact of motor (kW)No. ing shim surface (μm) 2000 RPM 4000 RPM______________________________________1 Silicon 1.5 1.13 1.24 nitride2 Silicon 1.2 1.11 1.22 nitride3 Silicon 1.0 1.08 1.18 nitride4 Silicon 0.7 1.00 1.10 nitride5 Silicon 0.5 0.94 1.03 nitride6 Silicon 0.2 0.90 0.99 nitride7 Silicon 0.05 0.89 0.98 nitride*8 Silicon 2.5 1.20 1.32 nitride*9 Silicon 5.0 1.32 1.45 nitride (not processed)*10 Cr--Mo 5.0 1.17 1.28 steel______________________________________ *comparative example
EXAMPLE 2
The adjusting shims produced out of various kinds of ceramic materials were subjected to the evaluation of power loss caused thereby by a method identical with that used in Example 1, and the results are shown in Table 2.
TABLE 2______________________________________Material Surface roughness Power consumptionfor adjust- Rz of contact of motor (kW)No. ing shim surface (μm) 2000 RPM 4000 RPM______________________________________11 Zirconia 0.05 0.91 1.0012 Zirconia 1.0 1.11 1.2213 Composite 1.0 1.09 1.19 material of SiC--Si.sub.3 N.sub.414 Composite 0.2 0.92 1.01 material of SiC--Si.sub.3 N.sub.4*15 Zirconia 5.0 1.34 1.47*16 Composite 8.0 material of (not processed) 1.36 1.49 SiC--Si.sub.3 N.sub.4*10 Cr--Mo 5.0 1.17 1.28 steel______________________________________ *comparative examples
EXAMPLE 3
Each of the adjusting shims produced under the same conditions as in Example 1 was subjected to a 200-hour continuous operation test with a motor rotated at a predetermined number of revolutions per minute (6000 RPM in terms of number of revolutions per minute of engine), by using the motoring system used in Example 1, and the abrasion loss, which was determined after the tests had been completed, of the valve lifter was evaluated. The evaluating of the abrasion loss of the valve lifter was done by measuring the inner diameter, which is shown by a reference numeral 11 in FIG. 2, of the valve lifter before and after each test was conducted, and determining the quantity of variation thereof. The results of the evaluation are shown in Table 3.
TABLE 3______________________________________ Surface Roughness Rz Abrasion Material for of contact surface loss**No. adjusting shim (μm) (μm)______________________________________17 Silicon nitride 1.5 1218 Silicon nitride 1.2 1119 Silicon nitride 1.0 1020 Silicon nitride 0.7 521 Silicon nitride 0.5 322 Silicon nitride 0.2 123 Silicon nitride 0.05 <1*24 Silicon nitride 2.5 18*25 Silicon nitride 5.0 20 (not processed)______________________________________ *comparative example **Abrasion loss: Difference between the inner diameter of valve lifter measured before test was conducted and that thereof measured after test was conducted.
The present invention is not limited to these embodiments. The surfaces of the adjusting shims were smoothed by being processed with a diamond wheel. Even if these surfaces are smoothed by being subjected to chemical and physical surface treatments (etching and coating), or a chemical applying treatment which is conducted before and after the sintering of a ceramic material, obtaining the same:effect as those in the embodiments can be expected. The same effect can also be expected even if the roughness of the surfaces designated by the reference numerals 8, 9 and 10 in FIG. 1 is set to different levels according to different purposes.
The adjusting shim according to the present invention enables a power loss and wear resistance of a valve operating system to be reduced and increased respectively, and the fuel consumption, performance and durability of an internal combustion engine to be improved.
TABLE 4__________________________________________________________________________ Surface treatment process andSurface roughness class of abrasive grain sizeRz of contact Power consumption of motor (kW) Ratio of Lapping +No. surface (μm) 2000 RPM 4000 RPM processing cost (%) Grinding Polishing__________________________________________________________________________26 0.05 0.89 0.98 100 #200 + #800 not done #120027* 0.03 1.02 1.14 900 #200 + #800 #2000 + #1200 #400028* 0.01 1.08 1.19 1800 #200 + #800 #2000 + #1200 #4000 + #8000 + #10000__________________________________________________________________________ Note: *Comparative Samples
|
The preset invention provides a ceramic adjusting shim capable of minimizing the abrasion of parts contacting the adjusting shim, for example, a cam and a tappet. The ceramic adjusting shim is produced from a ceramic material and has a surface roughness of 0.05 to 0.2 μm in ten-point average roughness Rz.
| 5
|
This is a divisional of application Ser. No. 09/021,500 filed on Feb. 10, 1998, now U.S. Pat. No. 6,007,758, issued Dec. 28, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to fabrication of devices formed from metallized magnetic substrates, e.g., inductors, transformers, and substrates for power applications.
2. Discussion of the Related Art
Magnetic components such as inductors and transformers are widely employed in circuits requiring energy storage and conversion, impedance matching, filtering, electromagnetic interference suppression, voltage and current transformation, and resonance. These components tend to be bulky and expensive compared to the other components of a circuit. Early is manufacturing methods typically involved wrapping conductive wire around a magnetic core element or an insulating body containing magnetic core material. These early methods resulted in circuit components with tall profiles, and such profiles restricted miniaturization of the devices in which the components were used. The size restriction was particularly problematic in power circuits such as power converters.
More recent efforts to improve upon these early manufacturing methods resulted in thick film techniques and multilayer green tape techniques. In a thick film technique, a sequence of thick film screen print operations are performed using a ferrite paste and a conductor paste. Specifically, individual ferrite layers are deposited as a paste to form a substrate, while the conductor paste is deposited between the individual ferrite paste layers to form conductive patterns through the interior of the substrate. Conductor paste is also printed onto the surfaces of the resulting multilayer ferrite substrate to connect the vias, thereby forming spiral windings. Upon firing, a consolidated body containing numerous devices is typically formed.
The green tape technique uses green tape layers composed of ferrite particles and organic binder to form the substrate. Typically, as shown in FIGS. 2A to 2C, numerous holes 22 are punched through each of several green tape layers 20 (for simultaneous formation of numerous devices). As shown in FIG. 2B, the side walls of the holes 22 are subsequently coated with a conductive material 24, and then the green tape layers 20 are stacked and laminated to form a substrate 30. As shown in FIG. 2C, conductor material 32 is printed onto the opposing surfaces of the multilayer substrate 30, and connected to the conductive material 24 coated onto the side walls of the holes 22, such that continuous, conductive windings are formed. The substrate 30 is fired to form a consolidated ceramic, and, typically, a metal such as copper is electroplated onto the windings to provide improved conductivity. Such green tape techniques experience problems, however. For example, due to the numerous, relatively small vias, it is sometimes difficult to attain a uniform electroplated layer in the vias due to mass transport limitations from the electroplating bath to the via surfaces. In addition, the adhesion of the electroplated layer on the conductive material is often problematic in green tape techniques.
Improved methods for forming devices that incorporate metallized magnetic substrates, such as inductors and transformers, are desired. Particularly desired are methods that offer improved fabrication speeds and device yields from a single multilayer substrate.
SUMMARY OF THE INVENTION
The invention provides an improved process for fabricating devices containing metallized magnetic ceramic material, such as inductors and transformers. In an embodiment of the invention, reflected in FIGS. 1A-1D, several layers of unfired magnetic material, typically ferrite tape, are provided. The vias 12, 13 of the invention are punched into the layers individually, at the same locations in each layer. Each via 12, 13, as initially punched, is capable of contacting two opposing windings, as reflected in FIG. 1C. (The vias 13 along the outer edges are referred to herein as outer vias, in contrast to the inner vias 12. These outer vias 13, due to their location along the edges of the substrate, are not intended to contact two opposing windings 16 of devices. It is possible, however, as reflected in FIGS. 1C and 1D, for an outer via 13 to contact both a winding 16 of a device and an opposing connection 15 to a bus 17.) The layers are then stacked such that the vias 12, 13 are aligned, and the layers are laminated to form a substrate 10 of the unfired magnetic material. The side walls of the aligned vias 12, 13 are coated with a conductive material 14, e.g., a silver- and palladium-containing ink (the term ink indicating a viscosity of about 5,000 to about 300,000 cp). Then, without expanding the dimensions of the vias 12, 13, e.g., without an additional punching step that contacts the vias, the top and bottom surfaces of the substrate 10 are coated with a second conductive material 16 to connect the side wall coatings of adjacent vias 12, 13, thereby forming conductive windings. It is then possible to score the substrate 10, as shown in FIG. 1D, to ease subsequent separation of devices. The substrate is fired, and additional metal, e.g., copper, is electroplated over the conductive material to form the finished devices.
The invention represents an improvement over the type of green tape technique discussed in co-assigned U.S. patent application Ser. No. 08/923591 (our reference Fleming-Johnson-Lambrecht-Law-Liptack-Roy-Thomson 13-49-831-3-20-36) (referred to herein as the '702 application), filed Sep. 4, 1997, now U.S. Pat. No. 5,802,702 the disclosure of which is hereby incorporated by reference. As reflected in FIGS. 3A to 3D, the '702 application discloses a method involving the following steps: (a) punching vias 42 in individual green ferrite sheets 40, (b) coating the side walls of the vias 42 of each sheet 40 with a conductive material 44, (c) punching large apertures 46 that intersect the vias 42 in each sheet 40 and thereby expand the dimensions of the vias 42, (d) laminating the sheets 40 with the vias 42 aligned to form a substrate 50, and (e) coating the surfaces of the substrate 50 with a second conductive material 48 to connect the coating 44 of the via 42 side walls, thereby forming windings. (Alternatively, the steps of punching the vias and punching the apertures are interchanged.) 5 The substrate is then fired, and a metal, e.g., copper, is electroplated over the metal ink. The apertures 46 are needed to open up access to the interior of the substrate 50, because uniform electroplating is difficult to attain in the small, narrow vias 42. In practice, it is necessary, before laminating the sheets 40 in step (d), to coat the surface of internal sheets with a conductive material, i.e., provide internal metallization, to connect the exposed vias with an external electroplating bus. This internal metallization is required to distribute current for electroplating because the apertures 46, as shown in FIG. 3C, create discontinuities in the first and second conductive materials 44, 48. Unfortunately, the time and expense required to provide such internal metallization, including the cost of the metal itself (Pd and Ag are commonly used), is typically disadvantageous. Also, the presence of the internal metallization demands a greater spacing between individual devices in a substrate, thereby reducing the number of devices capable of being produced in a single substrate. And the internal metallization is not always adequate to provide uniform plating, due to the difficulty in attaining good connectivity between the external and internal metallization.
In contrast to the above process, the present invention's use of vias capable of contacting two opposing winding (see FIG. 1C) allows for device fabrication using only a single punching step for each green tape layer. The single punching step in turn makes it possible to laminate all the unfired layers prior to coating the side walls of the vias, such that the vias of all the tape layers are coated simultaneously. Moreover, since no apertures are punched, i.e., the via dimensions are not expanded, there is no need for internal metallization. The invention thereby provides for green tape fabrication of devices in a manner faster and less complex than the above method.
The invention also relates to use of an improved conductive material to coat the surfaces of the ferrite substrates and the inner walls of the vias. The conductive material, which is applied as a conductive ink, contains silver/palladium particles, ferrite particles, an organic based binder (advantageously cellulose-based), and a solvent. (As used herein, silver/palladium particles indicates the presence of silver particles and palladium particles or of silver-palladium alloy particles.) Surprisingly, when copper is electroplated onto this improved conductive material using a copper pyrophosphate bath, the plated copper advantageously exhibits a pull strength of about 5 kpsi. By contrast, use of a conventional copper sulfate acid bath typically provides pull strengths of about 2 kpsi or less. (Pull strength indicates the strength of 0.08 inch diameter, 125 μm thick copper dots electroplated onto fired conductive material, the strength measured by attaching copper studs to the dots with epoxy and measuring the pull strength by conventional methods.) In addition, it was found that use of the copper pyrophosphate bath was effective in uniformly electroplating the side walls of multilayer laminates, i.e., uniformly electroplating narrow, deep vias.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1D show one embodiment of the invention.
FIGS. 2A to 2C show a prior art method for forming devices.
FIGS. 3A to 3D show an alternative green tape method for forming devices.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the process of the invention is shown in FIGS. 1A-1D. Several green tape layers of a magnetic material are provided. It is possible to use a single layer, but greater than two layers are typically used. The magnetic material is selected from any magnetic material capable of being metallized, e.g., magnetic ceramics and polymers loaded with magnetic particles, and typically has a magnetic permeability of about 400 to about 1000, and an electrical resistivity greater than about 10 6 ohm-cm. Green tape indicates a flexible material containing an organic binder and particles of the magnetic material. Typically, the tape contains about 8 to about 10 weight percent binder, based on the weight of the tape, with the remainder composed of a ceramic powder. Advantageously, the magnetic material is a spinel ferrite of the form M 1+x Fe 2-x O 4-z , where x and z range from -0.1 to +0.1. M is typically at least one of manganese, magnesium, nickel, zinc, iron, copper, cobalt, vanadium, cadmium, and chromium. Advantageous ferrites are those exhibiting relatively high resistivities, e.g., about 10 4 ohm-cm or higher, such as nickel-zinc ferrites and certain manganese-zinc ferrites, which are also known as soft ferrites. (Soft magnetic materials such as soft ferrites have coercivity less than about 10 Oe and are typically demagnetized in the absence of an external magnetic field.) Other suitable ferrites include so-called microwave ferrites, e.g., the garnet structure, or so-called square-loop ferrites, e.g., where M is manganese or magnesium. (Microwave ferrites are used for devices such as microwave circulators at frequencies in the range of 0.5 to 50 GHz. Square-loop ferrites exhibit a hysteresis loop with moderate coercivity and moderate remanence, and thus are capable of both retaining a flux density and being demagnetized in moderate magnetic fields.)
As shown in FIG. 1A, vias 12, 13 are punched into each green tape layer, at the same locations in each, and the layers are then stacked and laminated to form a multilayer substrate 10. Some of the vias 13 will be located along outer edges of the substrate (the left and right edges of the substrate shown in FIG. 1A). As mentioned previously, these vias 13 along the outer edges are referred to herein as outer vias, in contrast to the inner vias 12. These outer vias 13, due to their location along the edges of the substrate, are not intended to contact two opposing windings of devices. Typically, however, as reflected in FIGS. 1C and 1D, an outer via 13 will contact both a winding 16 of a device and an opposing connection 15 to a bus 17. The bus distributes the needed current during electroplating. While rectangular vias are shown in the FIGS., it is possible to form vias of a variety of geometries, e.g., square, circular, eliptical. Vias having aspect ratios (i.e., the ratio of the long to short axis) of about 1 to about 4 have been found to be useful. Vias 12, 13 are typically formed by placing the green tape layers in a suitable punch press. For green tapes formed from ceramic powder and organic binder, it is possible to laminate several layers of tape by pressing the layers together at a relatively low pressure, e.g., 250-3000 psi, at a temperature of about 50-100° C. To provide proper alignment of multiple layers, registration holes are typically punched in each layer during via formation, and registration rods are then placed through the holes to align the layers prior to lamination.
As shown in FIG. 1B, the side walls of the vias 12, 13 are coated with a first conductive material 14, e.g., a conductive ink. (The conductive material typically has a resistivity less than 10 -4 ohm-cm after firing.) The coating step advantageously results in formation of continuous side walls. (A few discontinuities, e.g. pinholes, are acceptable as long as the post-fired conductive material is capable of being electroplated.) Useful conductive inks include those containing silver and/or palladium particles, or silver-palladium alloy particles (the silver and palladium generally used in a 70 Ag:30 Pd weight ratio). Typically, conductive inks contain the metal as a particulate suspension in an organic binder, such that the ink is capable of being coated or screen printed. To coat the side walls of the vias 12, 13 the first conductive material 14 is normally drawn through the vias using vacuum suction, optionally using a coating mask cut to match the via pattern in substrate 10. Other coating or deposition methods are also possible.
As shown in FIG. 1C, following coating of inner side walls of vias 12, 13, the top and bottom surfaces of the substrate 10 are coated with a second conductive material 16, having post-fired properties similar to the first conductive material 14. Typically, the second conductive material 16 is screen printed to form a desired metallization pattern, e.g., windings, circuit lines, and surface mount pads. The pattern formed from the second conductive material 16 contacts the material 14 coated onto the side walls of the vias 12, 13, thereby forming continuous, conductive windings. As reflected in FIG. 1C, no expansion of the dimensions of the vias are needed, e.g., the vias 12, as initially punched, are capable of contacting two opposing windings. (The description of "no expansion of the dimensions of the vias" means that no affirmative expansion is performed, e.g., by further punching steps. Expansion of the vias due to other process steps, e.g., heat expansion during firing, is contemplated.) It is also possible to provide the surface coating of conductive material prior to lamination, and/or prior to via side wall coating. A bus 17 is also formed, along with contacts 15 from the bus 17 to the first conductive material 14 deposited in the outer vias 13.
The second conductive material 16 is advantageously a conductive ink similar to the first conductive material 14 used to coat the inner side walls of the vias 12. Where the substrate 10 is formed from a ferrite, it is advantageous for the first conductive material 14 and the second conductive material 16 to be silver- and palladium-containing ink that contains ferrite particles and an organic binder, advantageously a cellulose-based binder, this conductive ink discussed in detail below. Advantageously, the ink contains the same type ferrite as the substrate to improve adhesion to the substrate upon firing. When such a silver- and palladium-containing ink is used for the second conductive material 16, the ink is typically screen printed to a wet thickness of 25 to 75 μm. Subsequent to forming the surface metallization, it is advantageous to scribe dice lines 18 into the green tape 10, as shown in FIG. 1D, to facilitate separation of devices subsequent to sintering of the article. It is also possible to omit the dice lines, and instead saw the devices apart after sintering is complete.
After the windings are formed in the substrate 10, the substrate 10 is fired. Firing drives solvent and binder from the first and second conductive material 14, 16, thereby adhering the metal particles to the substrate 10, and the firing also sinters the substrate 10 to a dense ceramic. Copper is then electroplated onto the fired conductive material 14, 16, generally to a thickness of about 1 to about 10 mils, to form the final devices. The bus 17 and contacts 15 to the outer vias 13 provide the needed current during electroplating. It is possible to use a variety of conventional electroplating baths to deposit the copper onto the conductive material, and such baths are discussed generally in Metal Finishing Guidebook, Vol. 94, No 1A, 1996. Other conductive plating materials are also possible. Electroless plating is possible, but is typically slower and incapable of adequately providing a plating of desired thickness.
The first and second conductive materials discussed in the embodiment above are advantageously a conductive ink containing silver/palladium particles, ferrite particles, an organic binder, and a solvent, where the solvent primarily solvates the binder. Use of ferrite particles are advantageous for improving adhesion of subsequent electroplating deposits on the conductive material, and for reducing the amount of costly silver and palladium material that is required. The silver/palladium particles are typically used in a weight ratio of 60-80 Ag:40-20 Pd (typically 70 Ag:30 Pd), and have an average diameter of about 1 μm. The improved ink advantageously contains about 10 to about 50 wt. % ferrite particles, more advantageously about 20 to about 40 wt. %, in the post-fired material (i.e., based on the weight of the ferrite and conductive particles). Less than 10 wt. % ferrite particles typically results in an undesirably small increase in adhesion strength and cost reduction, while greater than 50 wt. % ferrite particles typically results in undesirably high electrical resistivity, which interferes with subsequent electroplating. The ferrite particles typically have an average diameter of about 0.2 to about 2.0 μm, advantageously about 1.5 μm. The ink typically contains about 1 to about 3 wt. % of the organic binder, and about 10 to about 40 wt. % of the solvent, based on the weight prior to firing. At lower amounts of binder and solvent, the viscosity of the ink is typically too high to use in the process described above, while at higher amounts, the viscosity is typically too low. The organic binder provides desired rheology and strength to the green structure. The binder is advantageously cellulose-based and more advantageously ethyl cellulose. A variety of solvents are useful, including α-terpineol and mineral spirits.
It is possible to fabricate the improved conductive ink by a variety of processes. In one such process, the binder is dissolved in a first solvent until substantially wet by the solvent. Particles of the ferrite and the conductive material are separately mixed with a second solvent (which is the same or different than the first solvent), e.g., ethanol, and typically a small amount, e.g., less than 1 wt. %, of a dispersant material such as oleic acid or another fatty acid. Once the powder mixture has settled, about 50-70 wt. % of the solvent is extracted. The appropriate amount of the binder solution is added to the metal powder to provide the desired amount of the binder material in the metal ink. Typically an additional amount of solvent is then added, and the components are mixed to provide the conductive ink. Viscosity of the ink is typically adjusted by altering the amount of solvent and/or binder. It is possible to use a control sample to determine the appropriate amounts of the components to provide a desired result. Normally, a less viscous ink is desired when plating the side walls of vias, e.g., 5,000 to 50,000 cp, whereas a more viscous ink, e.g., 30,000 to 300,000 cp, is useful for screen printing onto a surface of a ferrite substrate.
It was found that use of this improved conductive ink in combination with copper electroplating by a copper pyrophosphate bath provided desirable pull strengths for the plated copper. In particular, copper plated in this manner advantageously exhibits a pull strength greater than about 4 kpsi, more advantageously above 5 kpsi. (Pull strengths were measured as described in Comparative Example 1 and Example 3 below.) A copper pyrophosphate bath generally contains four components. Copper pyrophosphate is the source of copper and a complexing ion. Potassium pyrophosphate further provides a complexing ion, and an amount of free pyrophosphate required for plating. Potassium nitrate provides for good anode corrosion. And ammonia (typically introduced as ammonium hydroxide) provides morphology control of the plated deposit. Typically, conventional pH adjusting compounds are also used. A useful, commercially-available pH lowering compound is "Compound 4A" available from ATOTECH, and pyrophosphoric acid is similarly suitable. A useful pH raising compound is potassium hydroxide. Optionally, an additive is included to provide leveled, bright deposits, such additives commercially known and available. One such additive is additive PY61H, available from ATOTECH. Typically, leveler/brighteners consist of materials having organic backbones with attached alkoxy and/or hydroxyl groups.
A variety of parameters have been found to be particularly useful for plating copper on devices, particularly in the process for forming devices discussed above, utilizing copper pyrophosphate plating baths. The temperature of the bath is advantageously 50 to 55° C. Below 50° C., the quality of the deposit is reduced, and above 55° C., pyrophosphate undesirably begins rapid conversion to orthophosphate. The pH of the bath is advantageously 7.8 to 8.5, more advantageously 8.0 to 8.5. At pH values below 7.8, pyrophosphate undesirably begins rapid conversion to orthophosphate. At pH values above 8.5 the quality of the deposit is reduced. Anodes are advantageously oxygen-free copper. The ammonia is advantageously present in an amount ranging from 6 to 10 mL per L of bath solution. At lower ammonia concentrations, line definition is typically poor and spreading of the deposit from the conductive material onto the substrate occurs. At higher ammonia concentrations, the deposit tends to exhibit undesirable internal stresses. The orthophosphate concentration is advantageously less than 60 g/L, above which the orthophosphate lowers the quality of the plated deposit. The ammonium nitrate is advantageously present at a concentration of 8 to 12 g/L, within which desirable plating efficiency is attained. The ratio of pyrophospate to copper is advantageously 7.7 to 8.5. The copper concentration is advantageously 19.0 to 25.0 g/L. Plating is advantageously performed at a current density of 25 to 50 ASF (amperes per square foot). It is possible to use a control sample to determine the particular parameters that will provide a desired result.
A useful, commercially available copper pyrophosphate bath is the UNICHROME™ bath made by ATOTECH.
In the invention, it was found that use of copper pyrophosphate electroplating provided adequate uniformity of copper on the via side walls, even with deep, narrow vias having a large depth to width ratio. Thus, there is no need to punch large apertures to provide adequate electroplating, as in U.S. Pat. No. 5,802,702, referenced previously. And without the apertures, there is no need for internal metallization to provide electrical contact during electroplating. Eliminating the internal metallization reduces the complexity and cost of the process by removing the steps of printing metallization on internal green tape layers. A lack of internal metallization also improves the yield of the process because the devices are able to be spaced closer together, and faults due to poor connectivity between internal and external metallization are reduced.
The invention will be further clarified by the following examples, which are intended to be exemplary.
EXAMPLE 1
Formation of silver- and palladium- containing conductive inks containing ferrite particles:
A binder solution was formed by dissolving ethyl cellulose in α-terpineol, at a cellulose-terpineol weight ratio of between 1:10 and 1:12. The mixture was allowed to stand until the ethyl cellulose was substantially wet. The mixture was then passed through a 3-roll mill to further mix and homogenize the solution.
Silver and palladium particles (70:30 weight ratio) and ferrite particles (the metal particles having average diameters of about 1 μm) were mixed with ethanol, in an amount approximately half the total weight of the metal particles, and 0.5 wt. % oleic acid was then added. (The amount of each type of metal was determined based on the desired ferrite loading.) The mixture was then ultrasonicated for about 5 minutes. After several hours of settling of the metal particle mixture, about 60 wt. % solvent was extracted. The metal powder, however, was not allowed to dry.
The amount of binder solution needed to provide about 1.8 wt. % ethyl cellulose, based on the weight of the total ink (metal, ferrite, binder, and solvent) was determined, and that determined amount was added to the metal powder. The mixture was manually mixed and placed onto a slow roller mill for homogenization. The mixture was placed onto a 3-roll mill to evaporate the ethanol and obtain a desired viscosity. If necessary, additional α-terpineol was added to adjust the viscosity.
As prepared, the ink contained 74±2 wt. % metal powders and 1.8±0.1 wt. % ethyl cellulose, based on the weight of the overall ink composition.
EXAMPLE 2
Formation of a Device
An array of four turn, three layer surface mountable inductors was prepared in the following manner. Three 5"×5"×0.29" green, nickel-zinc ferrite (approximately Ni 0 .4 Zn 0 .6 Fe 2 O 4 ) tape layers were provided. Each tape contained ferrite powder and about 8 to about 10 wt. % organic binder. Vias having dimensions of 0.30"×0.3" were punched in each tape layer individually, such that two adjacent devices would share four vias. Registration holes were also punched in each layer to allow subsequent stacking of the layers. Planar conductor patterns (for windings and surface mount pads of the inductors), plating buss interconnects, and reference marks for scoring between the devices (to promote later separation) were provided on the top surface of the first tape layer and the bottom surface of the third tape layer. The planar conductor patterns and buss interconnects were formed from a silver- and palladium-containing ink made according to Example 1, containing 35 wt. % ferrite particles and 2 wt. % ethyl cellulose binder, with α-terpineol included to provide a desired viscosity.
The three tape layers were then stacked on a steel registration fixture and laminated together at a temperature of about 80 to about 90° C. and a pressure of about 250 to about 500 psi. Lamination caused the binder of the three layers to soften and fuse, thereby forming a relatively strong monolithic array. The side walls of the vias were then coated with the same metal ink used for the surface metallization. The viscosity of the ink was reduced beyond that used for the above printing step by addition of α-terpineol. The side walls were coated by drawing the ink through the vias with vacuum, to leave a coating on the side walls. After the ink dried, the array was scored on its top and bottom surfaces (as reflected in FIG. 1D) to promote singulation of the inductors subsequent to sintering and electroplating.
To co-sinter the ferrite and metal components, the array was placed on a flat Alundum® setter that was dusted with a sintered ferrite powder of the same composition (to prevent the substrate from sticking to the Alundum™). The array was then heated from room temperature to 500° C. over about 24 hours to volatilize the organic components of the tape and ink in a controlled manner. The temperature was further raised to about 1100° C. over about 24 hours, including a four hour treatment at about 1100° C. and cooling to room temperature. All heating was performed in a flowing air atmosphere (2.5 L/minute).
Plating of the fired array was performed in a copper pyrophosphate bath similar to the bath of Example 3, at 25 ASF, to a thickness of 0.005".
COMPARATIVE EXAMPLE 1
Pull Strength Measurements Using Copper Plated in Copper Sulfate Acid Bath
A set of 0.08 inch diameter dots was patterned onto a green ferrite tape, using conductive ink made according to the process of Example 1, having the ferrite loading discussed below. The tape was then fired in air at about 1100° C. for 4 hours. Copper was electroplated onto the dots to a thickness of 125 μm. The electroplating was performed in a copper sulfate acid bath at 25 ASF and room temperature. The bath contained 58.9 g/L of CuSO 4 , 120.0 mL/L of H 2 SO 4 , 3.0 mL/L of ATOTECH Cupracid Brightener, 15 mL/L of ATOTECH Cupracid BL-CT Basic Leveler, and 0.14 mL/L of HCl. Plating was performed at 25 ASF and room temperature. Copper studs were then attached to the copper dots with epoxy, and the pull strength was measured in a conventional manner using a Sebastian pull test apparatus.
This process was repeated for 8 samples using an ink containing 5 wt. % ferrite, based on the weight of the ink, and 8 samples using an ink containing 25 wt. % ferrite, based on the weight of the ink. For the 5 wt. % ferrite ink, the average pull strength was 1.70 kpsi, with a standard deviation of 74.00%. For two 25 wt. % ferrite samples, the average pull strengths were 1.26 kpsi with a standard deviation of 52.70%, and 1.68 kpsi with a standard deviation of 32.30%.
EXAMPLE 3
Pull Strength Measurements Using Copper Plated in Pyrophosphate Bath
A set of 0.08 inch dots was patterned onto a green ferrite tape, using conductive ink made according to the process of Example 1 with a ferrite loading of 25 wt. % based on the weight of the fired ink. The tape was then fired in air at 1115° C. for 4 hours. Copper was plated onto the dots to a thickness of 125 μm. The plating was performed in a copper pyrophosphate bath under the following conditions:
Bath:
210 mL of ATOTECH C-10 (66.7 g/L Cu; 499.5 g/L P 2 O 7 );
1980 mL of ATOTECH C-11 (481.5 g/L P 2 O 7 );
54 mL of NH 4 OH;
Initial pH of 10.10, adjusted and maintained at 8.15 by addition of pyrophosphoric acid.
Plating Conditions:
Temperature: 52° C.;
30 minutes at 5 ASF, followed by 200 minutes at 25 ASF.
Copper studs were then attached to the copper dots with epoxy, and the pull strength was measured in a conventional manner using a Sebastian pull test apparatus.
Nine samples were prepared in this manner. The average pull strength for the nine samples was 5.413±0.434 kpsi
|
The invention provides an improved process for fabricating devices containing metallized magnetic ceramic material, such as inductors, transformers, and magnetic substrates. In particular, the unique vias utilized in the process of the invention allow fabrication of devices from multiple unfired ferrite layers with only a single via-coating step, thereby avoiding the need numerous punching steps. Moreover, there is no need for expanding the dimensions of the vias and thus no need for internal metallization. The invention therefore provides for green tape-type fabrication of devices such as inductors, transformers, and magnetic substrates in a manner faster, less complex, and more reliable than current methods. The invention also relates to use of an improved conductive material in such a process, the conductive material containing silver/palladium particles, ferrite particles, a cellulose-based or other organic binder, and a solvent. After firing of the substrate onto which the ink has been coated, and plating of copper thereon by a copper pyrophosphate bath, the plated copper exhibits a pull strength greater than about 4 kpsi, advantageously greater than about 5 kpsi. Use of a copper pyrophosphate bath also allow uniform plating within long, narrow vias.
| 2
|
BACKGROUND OF THE INVENTION
[0001] The invention relates to improvements in elevator landing door assemblies and, more particularly, to a position control mechanism for multiple horizontal sliding door panels.
PRIOR ART
[0002] Freight elevator landing doors of the multiple panel, horizontal sliding type typically have a device to produce simultaneous movement of the panels. A common type of control device uses a cable and pulley system to produce the desired movement rate and distance which, as between the panels are-typically different but proportional.
[0003] Conventional cable systems are prone to go out of adjustment due to permanent stretching of the cables and/or wear of related parts. Generally, the cable systems are disposed above the door panels thereby making their original installation as well as subsequent service adjustments awkward, tedious and time-consuming.
SUMMARY OF THE INVENTION
[0004] The invention provides a multi-panel motion control system for a freight elevator door landing having a simplified linkage arrangement that is easy to install, requires minimal initial adjustment, and is resistant to wear or other distortion effects that require periodic adjustment or replacement. The linkage of the invention is adapted to be mounted at mid-height on the door panels so that it can be easily installed and adjusted by a technician conveniently working on the level of the respective landing.
[0005] Preferably, the linkage is in a multiple scissors or X-like configuration so that the forces on individual links and pivot connections or pins are balanced and relatively low forces are imposed on the linkage. Consequently, the linkage has the potential of operating over an extended service life with a minimum of wear, and thereby reduces the need for periodic service adjustment or replacement. Mounting brackets for the linkage can be directly secured to the panels and minimum initial adjustment is required. While a pinching hazard at the linkage is remote because in operation the linkage is ordinarily shielded by the elevator car door, the mechanism can include shields to minimize the risk of personal injury or mechanical damage when the linkage is exposed during periodic inspection or maintenance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is an elevational view from the inside of the elevator shaft of a door position control system constructed in accordance with the invention shown with associated door panels in a closed position;
[0007] FIG. 2 is a view similar to FIG. 1 , with the door panels and position control system in an open position;
[0008] FIG. 3 is an elevational edge view of the control system and door panels from a vantage point lateral of the shaft opening; and
[0009] FIG. 4 is a plan view of the door control system and door panels in an open position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] An assembly 10 of horizontal sliding door panels 11 a - 11 c, is illustrated in the figures. The panels 11 , for example, represent the right side of a six-panel door assembly. The left side of the assembly is symmetrical with and a mirror image of FIGS. 1 and 2 . The panels 11 are supported on traction rollers 12 supported on overhead tracks 13 in a generally conventional manner.
[0011] The door panel assembly 10 , as is typical, exists to close the shaft opening at a respective landing when an elevator car is elsewhere and opens for ingress and egress to the car when the car is present at the landing. The panels 11 , as seen most clearly in FIGS. 3 and 4 , are horizontally spaced or in staggered vertical planes so that they are able to register one behind the other as shown in FIG. 4 when in the open position.
[0012] When the panels 11 move between their respective open and closed positions, it is desirable that they all depart from and arrive at these positions at the same time. It follows that the inner door 11 a, i.e. the door that is spaced farthest from the shaft wall, must move the farthest and, therefore, the fastest, from and towards the center line of the shaft opening (or if the entire door assembly comprises only three panels, to the opposite side of the opening). The position and rate of travel of the door panels 11 in accordance with the present invention, is controlled by a linkage assembly or system 16 . The assembly 16 comprises a series of individual links pivotally connected to one another, to the panels 11 , and to a fixed referenced member or end bracket 17 . The links 18 , 19 are substantially uniform in length being either a short length or a long length, respectively, the latter being substantially equal to twice the short length. The short length links 18 have operative pivot connections only at their ends, while the long length links 19 have operative pivot connections at their ends-and at their mid-lengths so that they form an X or scissors-like configuration with other links 19 . As shown, the links 18 , 19 are proportioned so that in relation to the width of the door panels 11 such that when the panels are in the closed position of FIG. 1 , they are inclined from the horizontal by a substantial angle preferably at least about 30° so that high compressive forces along the axis of the links are avoided and the linkage 16 operates smoothly. The door panel 11 c, at the right in FIG. 1 , i.e. the door required to move the least distance between open and closed positions, is referred to as the slow door panel; the door panel 11 a at the left in FIG. 1 , i.e. the door panel required to move the greatest distance between open and closed positions, is referred to as the fast door panel; and the door panel 11 b, in between, is referred to as the middle door panel.
[0013] The linkage assembly 16 comprises a series of nodes 21 - 23 corresponding to the number of sliding door panels it controls. The nodes 21 , 23 associated with the slow and fast doors, respectively, comprise short links 18 and portions of long links 19 , while the intermediate or middle panel 11 b has its node comprised of portions of long links 19 .
[0014] The end bracket 17 provides a fixed reference point for the linkage system 16 . The bracket 17 is fixed by bolts to a rigid strut 24 or other stationary member spaced laterally of the landing-opening. The slow and middle door panels 11 c, 11 b, have associated L-shaped brackets 26 , 27 , as viewed in the plan view of FIG. 4 , screwed to vertical edges 28 of their respective door panels. The fast door panel 11 a has a bracket 29 attached to its side facing the shaft. This fast door panel bracket 29 carrying a pivot pin 30 is horizontally adjustable on the panel 11 a by virtue of slots 31 receiving screws attaching it to the panel. At the other end of the linkage 16 , a pivot pin 32 in the form of a shoulder bolt, is horizontally adjustable in a slot 33 in the bracket 17 . The slow and middle door panel brackets 26 , 27 support pivot pins 35 .
[0015] As shown in FIGS. 1 and 2 , the ends of the links remote from the bracket pins 30 , 32 , 35 , are each pivotally connected to one or two link ends by common pins. The links 18 , 19 are assembled on the bracket pins 30 , 32 , 35 and, as shown in FIG. 4 , the pins are arranged to support the links in three closely spaced parallel, vertical planes. Alternate links are doubled (going from left or right in FIGS. 1 and 2 , above or below the bracket pins) to straddle intervening single links. This straddling of intervening single links with double links tends to balance the operating forces on the links and pins and, thereby, avoids excessive eccentric loading on the parts and wear which would otherwise be attendant to such eccentric loading.
[0016] The slow, middle and end brackets 26 , 27 and 17 , are configured with pivot pin-supporting legs 36 , 37 , 38 that lie generally in a common vertical plane with the bracket 29 parallel to the door panels 11 . To accomplish this, the slow and middle brackets 26 , 27 , have legs 41 , 42 perpendicular to these pin supporting legs 36 , 37 of different lengths, each sufficient to reach the edges of their respective door panels to which they are attached by suitable screws. Additionally, the pivot pin supporting legs 36 , 37 are U-shaped so that the end bracket leg 38 can nest in the slow bracket leg 36 , and the slow bracket leg 36 can nest in the middle bracket leg 37 .
[0017] It can be seen that the pivot pin supporting bracket 29 on the fast door panel 11 a is horizontally adjustable with slots 31 that accept screws that fix it to this door panel. The horizontal adjustability of the shoulder bolt 32 on the end bracket 17 and the fast bracket 29 enables the linkage 16 to be adjusted so that in the open position, the door panels 11 can be aligned with the landing opening frame.
[0018] A set of guards 46 is mounted on the linkage 16 to reduce the already limited risk that a serviceman's hand or tools might be pinched between the links 18 , 19 when the door panels are being opened. The guards can be in the form of sheet metal or plastic strips that are assembled on pivot pins 47 coupling the ends of the links remote from the bracket pins 30 , 32 , 35 . The guards 46 are U-shaped when viewed from the edge in FIG. 3 . This U-shaped-configuration, with both vertical parts of the guard 46 pivoted on a respective pin 47 , allows the guard to be relatively stiff so that it remains in a vertical plane. The illustrated curved profiles of the brackets 17 , 26 and 27 also reduce the risk of a pinching hazard.
[0019] 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 door panel position control mechanism for a multiple panel horizontal sliding door assembly of a freight elevator landing. The mechanism comprises a multiple node scissors linkage that is configured to be easily installed and initially adjusted and which has its parts symmetrically balanced about a vertical plane such that excessive eccentric loading on the components is reduced and a long service life is obtained with reduced wear and a reduced need for periodic adjustment.
| 1
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent application Ser. No. 09/609,347, filed Jul. 5, 2000, which claims benefit of United States. Each of the aforementioned related patent applications is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to deposition of a metal layer onto a wafer/substrate. More particularly, the present invention relates to an electro-chemical deposition system or electroplating system for forming a metal layer on a wafer/substrate.
[0004] 2. Description of the Related Art
[0005] Sub-quarter micron, multi-level metallization is one of the key technologies for the next generation of ultra large scale integration (ULSI). The multilevel interconnects that lie at the heart of this technology require planarization of interconnect features formed in high aspect ratio apertures, including contacts, vias, lines and other features. Reliable formation of these interconnect features is very important to the success of ULSI and to the continued effort to increase circuit density and quality on individual substrates and die.
[0006] As circuit densities increase, the widths of vias, contacts and other features, as well as the dielectric materials between them, decrease to less than 250 nanometers, whereas the thickness of the dielectric layers remains substantially constant, with the result that the aspect ratios for the features, i.e., their height divided by width, increases. Many traditional deposition processes, such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), have difficulty filling structures where the aspect ratio exceed 4:1, and particularly where it exceeds 10:1. Therefore, there is a great amount of ongoing effort being directed at the formation of void-free, nanometer-sized features having high aspect ratios wherein the ratio of feature height to feature width can be 4:1 or higher. Additionally, as the feature widths decrease, the device current remains constant or increases, which results in an increased current density in the feature.
[0007] Elemental aluminum (Al) and its alloys have been the traditional metals used to form lines and plugs in semiconductor processing because of aluminum's perceived low electrical resistivity, its superior adhesion to silicon dioxide (SiO 2 ), its ease of patterning, and the ability to obtain it in a highly pure form. However, aluminum has a higher electrical resistivity than other more conductive metals such as copper, and aluminum also can suffer from electromigration leading to the formation of voids in the conductor.
[0008] Copper and its alloys have lower resistivities than aluminum and significantly higher electromigration resistance as compared to aluminum. These characteristics are important for supporting the higher current densities experienced at high levels of integration and increase device speed. Copper also has good thermal conductivity and is available in a highly pure state. Therefore, copper is becoming a choice metal for filling sub-quarter micron, high aspect ratio interconnect features on semiconductor substrates.
[0009] Despite the desirability of using copper for semiconductor device fabrication, choices of fabrication methods for depositing copper into very high aspect ratio features, such as a 4:1, having 0.35μ (or less) wide vias are limited. As a result of these process limitations, plating, which had previously been limited to the fabrication of lines on circuit boards, is just now being used to fill vias and contacts on semiconductor devices.
[0010] Metal electroplating is generally known and can be achieved by a variety of techniques. A typical method generally comprises physical vapor depositing a barrier layer over the feature surfaces, physical vapor depositing a conductive metal seed layer, preferably copper, over the barrier layer, and then electroplating a conductive metal over the seed layer to fill the structure/feature. Finally, the deposited layers and the dielectric layers are planarized, such as by chemical mechanical polishing (CMP), to define a conductive interconnect feature.
[0011] [0011]FIG. 1 is a cross sectional view of a simplified typical fountain plater 10 incorporating contact pins. Generally, the fountain plater 10 includes an electrolyte container 12 having a top opening, a substrate holder 14 disposed above the electrolyte container 12 , an anode 16 disposed at a bottom portion of the electrolyte container 12 and a contact ring 20 contacting the substrate 22 . A plurality of grooves 24 are formed in the lower surface of the substrate holder 14 . A vacuum pump (not shown) is coupled to the substrate holder 14 and communicates with the grooves 24 to create a vacuum condition capable of securing the substrate 22 to the substrate holder 14 during processing. The contact ring 20 comprises a plurality of metallic or semi-metallic contact pins 26 distributed about the peripheral portion of the substrate 22 to define a central substrate plating surface. The plurality of contact pins 26 extend radially inwardly over a narrow perimeter portion of the substrate 22 and contact a conductive seed layer of the substrate 22 at the tips of the contact pins 26 . A power supply (not shown) is attached to the pins 26 thereby providing an electrical bias to the substrate 22 . The substrate 22 is positioned above the cylindrical electrolyte container 12 and electrolyte flow impinges perpendicularly on the substrate plating surface during operation of the cell 10 .
[0012] While present day electroplating cells, such as the one shown in FIG. 1, achieve acceptable results on larger scale substrates, a number of obstacles impair consistent reliable electroplating onto substrates having micron-sized, high aspect ratio features. Generally, these obstacles include providing uniform power distribution and current density across the substrate plating surface to form a metal layer having uniform thickness, preventing unwanted edge and backside deposition to control contamination to the substrate being processed as well as subsequent substrates, and maintaining a vacuum condition which secures the substrate to the substrate holder during processing. Also, the present day electroplating cells have not provided satisfactory throughput to meet the demands of other processing systems and are not designed with a flexible architecture that is expandable to accommodate future designs rules and gap fill requirements. Furthermore, current electroplating system platforms have not provided post electrochemical deposition treatment, such as a rapid thermal anneal treatment, for enhancing deposition results within the same system platform.
[0013] Therefore, there remains a need for an electro-chemical deposition system that is designed with a flexible architecture that is expandable to accommodate future designs rules and gap fill requirements and provides satisfactory throughput to meet the demands of other processing systems. There is also a need for an electro-chemical deposition system that provides uniform power distribution and current density across the substrate plating surface to form a metal layer having uniform thickness and maintain a vacuum condition which secures the substrate to the substrate holder during processing. It would be desirable for the system to prevent and/or remove unwanted edge and backside deposition to control contamination to the substrate being processed as well as subsequent substrates. It would be further desirable for the electro-chemical deposition system to provide a post electrochemical deposition treatment, such as a rapid thermal anneal treatment, for enhancing deposition results.
SUMMARY OF THE INVENTION
[0014] The present invention generally provides an electro-chemical deposition system that is designed with a flexible architecture that is expandable to accommodate future designs rules and gap fill requirements and provides satisfactory throughput to meet the demands of other processing systems. The electro-chemical deposition system generally comprises a mainframe having a mainframe wafer transfer robot, a loading station disposed in connection with the mainframe, a rapid thermal anneal chamber disposed adjacent the loading station, one or more processing cells disposed in connection with the mainframe, and an electrolyte supply fluidly connected to the one or more electrical processing cells. Preferably, the electro-chemical deposition system includes a system controller adapted to control the electro-chemical deposition process and the components of the electro-chemical deposition system, including the rapid thermal anneal chamber disposed adjacent the loading station.
[0015] One aspect of the invention provides an electro-chemical deposition system that provides uniform power distribution and current density across the substrate plating surface to form a metal layer having uniform thickness and maintain a vacuum condition which secures the substrate to the substrate holder during processing.
[0016] Another aspect of the invention provides an electro-chemical deposition system that prevents and/or remove unwanted edge and backside deposition to control contamination to the substrate being processed as well as subsequent substrates.
[0017] Yet another aspect of the invention provides a post electrochemical deposition treatment, such as a rapid thermal anneal treatment, for enhancing deposition results. The apparatus for rapid thermal anneal treatment preferably comprises a rapid thermal anneal chamber disposed adjacent the loading station of the electrochemical deposition system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0019] So that the manner in which the above recited features, advantages and objects of the present invention are attained can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
[0020] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0021] [0021]FIG. 1 is a cross sectional view of a simplified typical fountain plater 10 incorporating contact pins.
[0022] [0022]FIG. 2 is a perspective view of an electroplating system platform 200 of the invention.
[0023] [0023]FIG. 3 is a schematic view of an electroplating system platform 200 of the invention.
[0024] [0024]FIG. 4 is a schematic perspective view of a spin-rinse-dry (SRD) module of the present invention, incorporating rinsing and dissolving fluid inlets.
[0025] [0025]FIG. 5 is a side cross sectional view of the spin-rinse-dry (SRD) module of FIG. 4 and shows a substrate in a processing position vertically disposed between fluid inlets.
[0026] [0026]FIG. 6 is a cross sectional view of an electroplating process cell 400 according to the invention.
[0027] [0027]FIG. 7 is a partial cross sectional perspective view of a cathode contact ring.
[0028] [0028]FIG. 8 is a cross sectional perspective view of the cathode contact ring showing an alternative embodiment of contact pads.
[0029] [0029]FIG. 9 is a cross sectional perspective view of the cathode contact ring showing an alternative embodiment of the contact pads and an isolation gasket.
[0030] [0030]FIG. 10 is a cross sectional perspective view of the cathode contact ring showing the isolation gasket.
[0031] [0031]FIG. 11 is a simplified schematic diagram of the electrical circuit representing the electroplating system through each contact pin.
[0032] [0032]FIG. 12 is a cross sectional view of a wafer assembly 450 of the invention.
[0033] [0033]FIG. 12A is an enlarged cross sectional view of the bladder area of FIG. 12.
[0034] [0034]FIG. 13 is a partial cross sectional view of a wafer holder plate.
[0035] [0035]FIG. 14 is a partial cross sectional view of a manifold.
[0036] [0036]FIG. 15 is a partial cross sectional view of a bladder.
[0037] [0037]FIG. 16 is a schematic diagram of an electrolyte replenishing system 600 .
[0038] [0038]FIG. 17 is a cross sectional view of a rapid thermal anneal chamber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] [0039]FIG. 2 is a perspective view of an electroplating system platform 200 of the invention. FIG. 3 is a schematic view of an electroplating system platform 200 of the invention. Referring to both FIGS. 2 and 3, the electroplating system platform 200 generally comprises a loading station 210 , a thermal anneal chamber 211 , a spin-rinse-dry (SRD) station 212 and a mainframe 214 . Preferably, the electroplating system platform 200 is enclosed in a clean environment using panels such as plexiglass panels. The mainframe 214 generally comprises a mainframe transfer station 216 and a plurality of processing stations 218 . Each processing station 218 includes one or more processing cells 240 . An electrolyte replenishing system 220 is positioned adjacent the electroplating system platform 200 and connected to the process cells 240 individually to circulate electrolyte used for the electroplating process. The electroplating system platform 200 also includes a control system 222 , typically comprising a programmable microprocessor.
[0040] The loading station 210 preferably includes one or more wafer cassette receiving areas 224 , one or more loading station transfer robots 228 and at least one wafer orientor 230 . The number of wafer cassette receiving areas, loading station transfer robots 228 and wafer orientor included in the loading station 210 can be configured according to the desired throughput of the system. As shown for one embodiment in FIGS. 2 and 3, the loading station 210 includes two wafer cassette receiving areas 224 , two loading station transfer robots 228 and one wafer orientor 230 . A wafer cassette 232 containing wafers 234 is loaded onto the wafer cassette receiving area 224 to introduce wafers 234 into the electroplating system platform. The loading station transfer robot 228 transfers wafers 234 between the wafer cassette 232 and the wafer orientor 230 . The loading station transfer robot 228 comprises a typical transfer robot commonly known in the art. The wafer orientor 230 positions each wafer 234 in a desired orientation to ensure that the wafer is properly processed. The loading station transfer robot 228 also transfers wafers 234 between the loading station 210 and the SRD station 212 and between the loading station 210 and the thermal anneal chamber 211 .
[0041] [0041]FIG. 4 is a schematic perspective view of a spin-rinse-dry (SRD) module of the present invention, incorporating rinsing and dissolving fluid inlets. FIG. 5 is a side cross sectional view of the spin-rinse-dry (SRD) module of FIG. 4 and shows a substrate in a processing position vertically disposed between fluid inlets. Preferably, the SRD station 212 includes one or more SRD modules 236 and one or more wafer pass-through cassettes 238 . Preferably, the SRD station 212 includes two SRD modules 236 corresponding to the number of loading station transfer robots 228 , and a wafer pass-through cassette 238 is positioned above each SRD module 236 . The wafer pass-through cassette 238 facilitates wafer transfer between the loading station 210 and the mainframe 214 . The wafer pass-through cassette 238 provides access to and from both the loading station transfer robot 228 and a robot in the mainframe transfer station 216 .
[0042] Referring to FIGS. 4 and 5, the SRD module 238 comprises a bottom 330 a and a sidewall 330 b , and an upper shield 330 c which collectively define a SRD module bowl 330 d , where the shield attaches to the sidewall and assists in retaining the fluids within the SRD module. Alternatively, a removable cover could also be used. A pedestal 336 , located in the SRD module, includes a pedestal support 332 and a pedestal actuator 334 . The pedestal 336 supports the substrate 338 (shown in FIG. 5) on the pedestal upper surface during processing. The pedestal actuator 334 rotates the pedestal to spin the substrate and raises and lowers the pedestal as described below. The substrate may be held in place on the pedestal by a plurality of clamps 337 . The clamps pivot with centrifugal force and engage the substrate preferably in the edge exclusion zone of the substrate. In a preferred embodiment, the clamps engage the substrate only when the substrate lifts off the pedestal during the processing. Vacuum passages (not shown) may also be used as well as other holding elements. The pedestal has a plurality of pedestal arms 336 a and 336 b , so that the fluid through the second nozzle may impact as much surface area on the lower surface of the substrate as is practical. An outlet 339 allows fluid to be removed from the SRD module. The terms “below”, “above”, “bottom”, “top”, “up”, “down”, “upper”, and “lower” and other positional terms used herein are shown with respect to the embodiments in the figures and may be varied depending on the relative orientation of the processing apparatus.
[0043] A first conduit 346 , through which a first fluid 347 flows, is connected to a valve 347 a . The conduit may be hose, pipe, tube, or other fluid containing conduits. The valve 347 a controls the flow of the first fluid 347 and may be selected from a variety of valves including a needle, globe, butterfly, or other valve types and may include a valve actuator, such as a solenoid, that can be controlled with a controller 362 . The conduit 346 connects to a first fluid inlet 340 that is located above the substrate and includes a mounting portion 342 to attach to the SRD module and a connecting portion 344 to attach to the conduit 346 . The first fluid inlet is shown with a single first nozzle 348 to deliver a first fluid 347 under pressure onto the substrate upper surface. However, multiple nozzles could be used and multiple fluid inlets could be positioned about the inner perimeter of the SRD module. Preferably, nozzles placed above the substrate should be outside the diameter of the substrate to lessen the risk of the nozzles dripping on the substrate. The first fluid inlet could be mounted in a variety of locations, including through a cover positioned above the substrate. Additionally, the nozzle may articulate to a variety of positions using an articulating member 343 , such as a ball and socket joint.
[0044] Similar to the first conduit and related elements described above, a second conduit 352 is connected to a control valve 349 a and a second fluid inlet 350 with a second nozzle 351 . The second fluid inlet 350 is shown below the substrate and angled upward to direct a second fluid under the substrate through the second nozzle 351 . Similar to the first fluid inlet, the second fluid inlet may include a plurality of nozzles, a plurality of fluid inlets and mounting locations, and a plurality of orientations including using the articulating member 353 . Each fluid inlet could be extended into the SRD module at a variety of positions. For instance, if the flow is desired to be a certain angle that is directed back toward the SRD module periphery along the edge of the substrate, the nozzles could be extended radially inward and the discharge from the nozzles be directed back toward the SRD module periphery.
[0045] The controller 362 could individually control the two fluids and their respective flow rates, pressure, and timing, and any associated valving, as well as the spin cycle(s). The controller could be remotely located, for instance, in a control panel or control room and the plumbing controlled with remote actuators. An alternative embodiment, shown in dashed lines, provides an auxiliary fluid inlet 346 a connected to the first conduit 346 with a conduit 346 b and having a control valve 346 c , which may be used to flow a rinsing fluid on the backside of the substrate after the dissolving fluid is flown without having to reorient the substrate or switch the flow through the second fluid inlet to a rinsing fluid.
[0046] In one embodiment, the substrate is mounted with the deposition surface of the disposed face up in the SRD module bowl. As will be explained below, for such an arrangement, the first fluid inlet would generally flow a rinsing fluid, typically deionized water or alcohol. Consequently, the backside of the substrate would be mounted facing down and a fluid flowing through the second fluid inlet would be a dissolving fluid, such as an acid, including hydrochloric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, or other dissolving liquids or fluids, depending on the material to be dissolved. Alternatively, the first fluid and the second fluid are both rinsing fluids, such as deionized water or alcohol, when the desired process is to rinse the processed substrate.
[0047] In operation, the pedestal is in a raised position, shown in FIG. 4, and a robot (not shown) places the substrate, front side up, onto the pedestal. The pedestal lowers the substrate to a processing position where the substrate is vertically disposed between the first and the second fluid inlets. Generally, the pedestal actuator rotates the pedestal between about 5 to about 5000 rpm, with a typical range between about 20 to about 2000 rpm for a 200 mm substrate. The rotation causes the lower end 337 a of the clamps to rotate outward about pivot 337 b , toward the periphery of the SRD module sidewall, due to centrifugal force. The clamp rotation forces the upper end 337 c of the clamp inward and downward to center and hold the substrate 338 in position on the pedestal 336 , preferably along the substrate edge. The clamps may rotate into position without touching the substrate and hold the substrate in position on the pedestal only if the substrate significantly lifts off the pedestal during processing. With the pedestal rotating the substrate, a rinsing fluid is delivered onto the substrate front side through the first fluid inlet 340 . The second fluid, such as an acid, is delivered to the backside surface through the second fluid inlet to remove any unwanted deposits. The dissolving fluid chemically reacts with the deposited material and dissolves and then flushes the material away from the substrate backside and other areas where any unwanted deposits are located. In a preferred embodiment, the rinsing fluid is adjusted to flow at a greater rate than the dissolving fluid to help protect the front side of the substrate from the dissolving fluid. The first and second fluid inlets are located for optimal performance depending on the size of the substrate, the respective flow rates, spray patterns, and amount and type of deposits to be removed, among other factors. In some instances, the rinsing fluid could be routed to the second fluid inlet after a dissolving fluid has dissolved the unwanted deposits to rinse the backside of the substrate. In other instances, an auxiliary fluid inlet connected to flow rinsing fluid on the backside of the substrate could be used to rinse any dissolving fluid residue from the backside. After rinsing the front side and/or backside of the substrate, the fluid(s) flow is stopped and the pedestal continues to rotate, spinning the substrate, and thereby effectively drying the surface.
[0048] The fluid(s) is generally delivered in a spray pattern, which may be varied depending on the particular nozzle spray pattern desired and may include a fan, jet, conical, and other patterns. One spray pattern for the first and second fluids through the respective fluid inlets, when the first fluid is a rinsing fluid, is fan pattern with a pressure of about 10 to about 15 pounds per square inch (psi) and a flow rate of about 1 to about 3 gallons per minute (gpm) for a 200 mm wafer.
[0049] The invention could also be used to remove the unwanted deposits along the edge of the substrate to create an edge exclusion zone. By adjustment of the orientation and placement of the nozzles, the flow rates of the fluids, the rotational speed of the substrate, and the chemical composition of the fluids, the unwanted deposits could be removed from the edge and/or edge exclusion zone of the substrate as well. Thus, substantially preventing dissolution of the deposited material on the front side surface may not necessarily include the edge or edge exclusion zone of the substrate. Also, preventing dissolution of the deposited material on the front side surface is intended to include at least preventing the dissolution so that the front side with the deposited material is not impaired beyond a commercial value.
[0050] One method of accomplishing the edge exclusion zone dissolution process is to rotate the disk at a slower speed, such as about 100 to about 1000 rpm, while dispensing the dissolving fluid on the backside of the substrate. The centrifugal force moves the dissolving fluid to the edge of the substrate and forms a layer of fluid around the edge due to surface tension of the fluid, so that the dissolving fluid overlaps from the backside to the front side in the edge area of the substrate. The rotational speed of the substrate and the flow rate of the dissolving fluid may be used to determine the extent of the overlap onto the front side. For instance, a decrease in rotational speed or an increase in flow results in a less overlap of fluid to the opposing side, e.g., the front side. Additionally, the flow rate and flow angle of the rinsing fluid delivered to the front side can be adjusted to offset the layer of dissolving fluid onto the edge and/or frontside of the substrate. In some instances, the dissolving fluid may be used initially without the rinsing fluid to obtain the edge and/or edge exclusion zone removal, followed by the rinsing/dissolving process of the present invention described above.
[0051] The SRD module 238 is connected between the loading station 210 and the mainframe 214 . The mainframe 214 generally comprises a mainframe transfer station 216 and a plurality of processing stations 218 . Referring to FIGS. 2 and 3, the mainframe 214 , as shown, includes two processing stations 218 , each processing station 218 having two processing cells 240 . The mainframe transfer station 216 includes a mainframe transfer robot 242 . Preferably, the mainframe transfer robot 242 comprises a plurality of individual robot arms 244 that provides independent access of wafers in the processing stations 218 and the SRD stations 212 . As shown in FIG. 3, the mainframe transfer robot 242 comprises two robot arms 244 , corresponding to the number of processing cells 240 per processing station 218 . Each robot arm 244 includes a robot blade 246 for holding a wafer during a wafer transfer. Preferably, each robot arm 244 is operable independently of the other arm to facilitate independent transfers of wafers in the system. Alternatively, the robot arms 244 operate in a linked fashion such that one robot extends as the other robot arm retracts.
[0052] Preferably, the mainframe transfer station 216 includes a flipper robot 248 that facilitates transfer of a wafer from a face-up position on the robot blade 246 of the mainframe transfer robot 242 to a face down position for a process cell 240 that requires face-down processing of wafers. The flipper robot 248 includes a main body 250 that provides both vertical and rotational movements with respect to a vertical axis of the main body 250 and a flipper robot arm 252 that provides rotational movement along a horizontal axis along the flipper robot arm 252 . Preferably, a vacuum suction gripper 254 , disposed at the distal end of the flipper robot arm 252 , holds the wafer as the wafer is flipped and transferred by the flipper robot 248 . The flipper robot 248 positions a wafer 234 into the processing cell 240 for face-down processing. The details of the electroplating processing cell according to the invention will be discussed below.
[0053] [0053]FIG. 6 is a cross sectional view of an electroplating process cell 400 according to the invention. The electroplating process cell 400 as shown in FIG. 6 is the same as the electroplating process cell 240 as shown in FIGS. 2 and 3. The processing cell 400 generally comprises a head assembly 410 , a process kit 420 and an electrolyte collector 440 . Preferably, the electrolyte collector 440 is secured onto the body 442 of the mainframe 214 over an opening 443 that defines the location for placement of the process kit 420 . The electrolyte collector 440 includes an inner wall 446 , an outer wall 448 and a bottom 447 connecting the walls. An electrolyte outlet 449 is disposed through the bottom 447 of the electrolyte collector 440 and connected to the electrolyte replenishing system 220 (shown in FIG. 2) through tubes, hoses, pipes or other fluid transfer connectors.
[0054] The head assembly 410 is mounted onto a head assembly frame 452 . The head assembly frame 452 includes a mounting post 454 and a cantilever arm 456 . The mounting post 454 is mounted onto the body 442 of the mainframe 214 , and the cantilever arm 456 extends laterally from an upper portion of the mounting post 454 . Preferably, the mounting post 454 provides rotational movement with respect to a vertical axis along the mounting post to allow rotation of the head assembly 410 . The head assembly 410 is attached to a mounting plate 460 disposed at the distal end of the cantilever arm 456 . The lower end of the cantilever arm 456 is connected to a cantilever arm actuator 457 , such as a pneumatic cylinder, mounted on the mounting post 454 . The cantilever arm actuator 457 provides pivotal movement of the cantilever arm 456 with respect to the joint between the cantilever arm 456 and the mounting post 454 . When the cantilever arm actuator 457 is retracted, the cantilever arm 456 moves the head assembly 410 away from the process kit 420 to provide the spacing required to remove and/or replace the process kit 420 from the electroplating process cell 400 . When the cantilever arm actuator 457 is extended, the cantilever arm 456 moves the head assembly 410 toward the process kit 420 to position the wafer in the head assembly 410 in a processing position.
[0055] The head assembly 410 generally comprises a wafer holder assembly 450 and a wafer assembly actuator 458 . The wafer assembly actuator 458 is mounted onto the mounting plate 460 , and includes a head assembly shaft 462 extending downwardly through the mounting plate 460 . The lower end of the head assembly shaft 462 is connected to the wafer holder assembly 450 to position the wafer holder assembly 450 in a processing position and in a wafer loading position.
[0056] The wafer holder assembly 450 generally comprises a wafer holder 464 and a cathode contact ring 466 . FIG. 7 is a cross sectional view of one embodiment of a cathode contact ring 466 of the present invention. In general, the contact ring 466 comprises an annular body having a plurality of conducting members disposed thereon. The annular body is constructed of an insulating material to electrically isolate the plurality of conducting members. Together the body and conducting members form a diametrically interior substrate seating surface which, during processing, supports a substrate and provides a current thereto.
[0057] Referring now to FIG. 7 in detail, the contact ring 466 generally comprises a plurality of conducting members 765 at least partially disposed within an annular insulative body 770 . The insulative body 770 is shown having a flange 762 and a downward sloping shoulder portion 764 leading to a substrate seating surface 768 located below the flange 762 such that the flange 762 and the substrate seating surface 768 lie in offset and substantially parallel planes. Thus, the flange 762 may be understood to define a first plane while the substrate seating surface 768 defines a second plane parallel to the first plane wherein the shoulder 764 is disposed between the two planes. However, contact ring design shown in FIG. 7 is intended to be merely illustrative. In another embodiment, the shoulder portion 764 may be of a steeper angle including a substantially vertical angle so as to be substantially normal to both the flange 762 and the substrate seating surface 768 . Alternatively, the contact ring 466 may be substantially planar thereby eliminating the shoulder portion 764 . However, for reasons described below, a preferred embodiment comprises the shoulder portion 764 shown in FIG. 6 or some variation thereof.
[0058] The conducting members 765 are defined by a plurality of outer electrical contact pads 780 annularly disposed on the flange 762 , a plurality of inner electrical contact pads 772 disposed on a portion of the substrate seating surface 768 , and a plurality of embedded conducting connectors 776 which link the pads 772 , 780 to one another. The conducting members 765 are isolated from one another by the insulative body 770 which may be made of a plastic such as polyvinylidenefluoride (PVDF), perfluoroalkoxy resin (PFA), Teflon™, and Tefzel™, or any other insulating material such as Alumina (Al 2 O 3 ) or other ceramics. The outer contact pads 780 are coupled to a power supply (not shown) to deliver current and voltage to the inner contact pads 772 via the connectors 776 during processing. In turn, the inner contact pads 772 supply the current and voltage to a substrate by maintaining contact around a peripheral portion of the substrate. Thus, in operation the conducting members 765 act as discrete current paths electrically connected to a substrate.
[0059] Low resistivity, and conversely high conductivity, are directly related to good plating. To ensure low resistivity, the conducting members 765 are preferably made of copper (Cu), platinum (Pt), tantalum (Ta), titanium (Ti), gold (Au), silver (Ag), stainless steel or other conducting materials. Low resistivity and low contact resistance may also be achieved by coating the conducting members 765 with a conducting material. Thus, the conducting members 765 may, for example, be made of copper (resistivity for copper is approximately 2×10 −8 Ω.m) and be coated with platinum (resistivity for platinum is approximately 10.6×10 −8 Ω.m). Coatings such as tantalum nitride (TaN), titanium nitride (TiN), rhodium (Rh), Au, Cu, or Ag on a conductive base materials such as stainless steel, molybdenum (Mo), Cu, and Ti are also possible. Further, since the contact pads 772 , 780 are typically separate units bonded to the conducting connectors 776 , the contact pads 772 , 780 may comprise one material, such as Cu, and the conducting members 765 another, such as stainless steel. Either or both of the pads 772 , 180 and conducting connectors 776 may be coated with a conducting material. Additionally, because plating repeatability may be adversely affected by oxidation which acts as an insulator, the inner contact pads 772 preferably comprise a material resistant to oxidation such as Pt, Ag, or Au.
[0060] In addition to being a function of the contact material, the total resistance of each circuit is dependent on the geometry, or shape, of the inner contact inner contact pads 772 and the force supplied by the contact ring 466 . These factors define a constriction resistance, R CR , at the interface of the inner contact pads 772 and the substrate seating surface 768 due to asperities between the two surfaces. Generally, as the applied force is increased the apparent area is also increased. The apparent area is, in turn, inversely related to R CR so that an increase in the apparent area results in a decreased R CR . Thus, to minimize overall resistance it is preferable to maximize force. The maximum force applied in operation is limited by the yield strength of a substrate which may be damaged under excessive force and resulting pressure. However, because pressure is related to both force and area, the maximum sustainable force is also dependent on the geometry of the inner contact pads 772 . Thus, while the contact pads 772 may have a flat upper surface as in FIG. 7, other shapes may be used to advantage. For example, two preferred shapes are shown in FIGS. 8 and 9. FIG. 8 shows a knife-edge contact pad and FIG. 9 shows a hemispherical contact pad. A person skilled in the art will readily recognize other shapes which may be used to advantage. A more complete discussion of the relation between contact geometry, force, and resistance is given in Ney Contact Manual, by Kenneth E. Pitney, The J. M. Ney Company, 1973, which is hereby incorporated by reference in its entirety.
[0061] The number of connectors 776 may be varied depending on the particular number of contact pads 772 (shown in FIG. 7) desired. For a 200 mm substrate, preferably at least twenty-four connectors 776 are spaced equally over 360°. However, as the number of connectors reaches a critical level, the compliance of the substrate relative to the contact ring 466 is adversely affected. Therefore, while more than twenty-four connectors 776 may be used, contact uniformity may eventually diminish depending on the topography of the contact pads 772 and the substrate stiffness. Similarly, while less than twenty-four connectors 776 may be used, current flow is increasingly restricted and localized, leading to poor plating results. Since the dimensions of the present invention are readily altered to suit a particular application (for example, a 300 mm substrate), the optimal number may easily be determined for varying scales and embodiments.
[0062] As shown in FIG. 10, the substrate seating surface 768 comprises an isolation gasket 782 disposed on the insulative body 770 and extending diametrically interior to the inner contact pads 772 to define the inner diameter of the contact ring 466 . The isolation gasket 782 preferably extends slightly above the inner contact pads 772 (e.g., a few mils) and preferably comprises an elastomer such as Viton™, Teflon™, buna rubber and the like. Where the insulative body 770 also comprises an elastomer the isolation gasket 782 may be of the same material. In the latter embodiment, the isolation gasket 782 and the insulative body 770 may be monolithic, i.e., formed as a single piece. However, the isolation gasket 782 is preferably separate from the insulative body 770 so that it may be easily removed for replacement or cleaning.
[0063] While FIG. 10 shows a preferred embodiment of the isolation gasket 782 wherein the isolation gasket is seated entirely on the insulative body 770 , FIGS. 8 and 9 show an alternative embodiment. In the latter embodiment, the insulative body 770 is partially machined away to expose the upper surface of the connecting member 776 and the isolation gasket 782 is disposed thereon. Thus, the isolation gasket 782 contacts a portion of the connecting member 776 . This design requires less material to be used for the inner contact pads 772 which may be advantageous where material costs are significant such as when the inner contact pads 772 comprise gold. Persons skilled in the art will recognize other embodiments which do not depart from the scope of the present invention.
[0064] During processing, the isolation gasket 782 maintains contact with a peripheral portion of the substrate plating surface and is compressed to provide a seal between the remaining cathode contact ring 466 and the substrate. The seal prevents the electrolyte from contacting the edge and backside of the substrate. As noted above, maintaining a clean contact surface is necessary to achieving high plating repeatability. Previous contact ring designs did not provide consist plating results because contact surface topography varied over time. The contact ring of the present invention eliminates, or least minimizes, deposits which would otherwise accumulate on the inner contact pads 772 and change their characteristics thereby producing highly repeatable, consistent, and uniform plating across the substrate plating surface.
[0065] [0065]FIG. 11 is a simplified schematic diagram representing a possible configuration of the electrical circuit for the contact ring 466 . To provide a uniform current distribution between the conducting members 765 , an external resistor 700 is connected in series with each of the conducting members 765 . Preferably, the resistance value of the external resistor 700 (represented as R EXT ) is much greater than the resistance of any other component of the circuit. As shown in FIG. 11, the electrical circuit through each conducting member 765 is represented by the resistance of each of the components connected in series with the power supply 702 . R E represents the resistance of the electrolyte, which is typically dependent on the distance between the anode and the cathode contact ring and the composition of the electrolyte chemistry. Thus, R A represents the resistance of the electrolyte adjacent the substrate plating surface 754 . R S represents the resistance of the substrate plating surface 754 , and R C represents the resistance of the cathode conducting members 765 plus the constriction resistance resulting at the interface between the inner contact pads 772 and the substrate plating layer 754 . Generally, the resistance value of the external resistor (R EXT ) is at least as much as ΣR (where ΣR equals the sum of R E , R A , R S R C ). Preferably, the resistance value of the external resistor (R EXT ) is much greater than ΣR such that ΣR is negligible and the resistance of each series circuit approximates R EXT .
[0066] Typically, one power supply is connected to all of the outer contact pads 780 of the cathode contact ring 466 , resulting in parallel circuits through the inner contact pads 772 . However, as the inner contact pad-to-substrate interface resistance varies with each inner contact pad 772 , more current will flow, and thus more plating will occur, at the site of lowest resistance. However, by placing an external resistor in series with each conducting member 765 , the value or quantity of electrical current passed through each conducting member 765 becomes controlled mainly by the value of the external resistor. As a result, the variations in the electrical properties between each of the inner contact pads 772 do not affect the current distribution on the substrate, and a uniform current density results across the plating surface which contributes to a uniform plating thickness. The external resistors also provide a uniform current distribution between different substrates of a process-sequence.
[0067] Although the contact ring 466 of the present invention is designed to resist deposit buildup on the inner contact pads 772 , over multiple substrate plating cycles the substrate-pad interface resistance may increase, eventually reaching an unacceptable value. An electronic sensor/alarm 704 can be connected across the external resistor 700 to monitor the voltage/current across the external resistor to address this problem. If the voltage/current across the external resistor 700 falls outside of a preset operating range that is indicative of a high substrate-pad resistance, the sensor/alarm 704 triggers corrective measures such as shutting down the plating process until the problems are corrected by an operator. Alternatively, a separate power supply can be connected to each conducting member 765 and can be separately controlled and monitored to provide a uniform current distribution across the substrate. A very smart system (VSS) may also be used to modulate the current flow. The VSS typically comprises a processing unit and any combination of devices known in the industry used to supply and/or control current such as variable resistors, separate power supplies, etc. As the physiochemical, and hence electrical, properties of the inner contact pads 772 change over time, the VSS processes and analyzes data feedback. The data is compared to pre-established setpoints and the VSS then makes appropriate current and voltage alterations to ensure uniform deposition.
[0068] Referring to FIG. 6 and FIG. 12, preferably, the wafer holder 464 is positioned above the cathode contact ring 466 and comprises a bladder assembly 470 that provides pressure to the backside of a wafer and ensures electrical contact between the wafer plating surface and the cathode contact ring 466 . The inflatable bladder assembly 470 is disposed on a wafer holder plate 832 . A bladder 836 disposed on a lower surface of the wafer holder plate 832 is thus located opposite and adjacent to the contacts on the cathode contact ring 466 with the substrate 821 interposed therebetween. A fluid source 838 supplies a fluid, i.e., a gas or liquid, to the bladder 836 allowing the bladder 836 to be inflated to varying degrees.
[0069] Referring now to FIGS. 12, 12A, and 13 , the details of the bladder assembly 470 will be discussed. The wafer holder plate 832 is shown as substantially disc-shaped having an annular recess 840 formed on a lower surface and a centrally disposed vacuum port 841 . One or more inlets 842 are formed in the wafer holder plate 832 and lead into the relatively enlarged annular mounting channel 843 and the annular recess 840 . Quick-disconnect hoses 844 couple the fluid source 838 to the inlets 842 to provide a fluid thereto. The vacuum port 841 is preferably attached to a vacuum/pressure pumping system 859 adapted to selectively supply a pressure or create a vacuum at a backside of the substrate 821 . The pumping system 859 , shown in FIG. 12, comprises a pump 845 , a cross-over valve 847 , and a vacuum ejector 849 (commonly known as a venturi). One vacuum ejector that may be used to advantage in the present invention is available from SMC Pneumatics, Inc., of Indianapolis, Ind. The pump 845 may be a commercially available compressed gas source and is coupled to one end of a hose 851 , the other end of the hose 851 being coupled to the vacuum port 841 . The hose 851 is split into a pressure line 853 and a vacuum line 855 having the vacuum ejector 849 disposed therein. Fluid flow is controlled by the cross-over valve 847 which selectively switches communication with the pump 845 between the pressure line 853 and the vacuum line 855 . Preferably, the cross-over valve has an OFF setting whereby fluid is restricted from flowing in either direction through hose 851 . A shut-off valve 861 disposed in hose 851 prevents fluid from flowing from pressure line 855 upstream through the vacuum ejector 849 . The desired direction of fluid flow is indicated by arrows.
[0070] Persons skilled in the art will readily appreciate other arrangements which do not depart from the spirit and scope of the present invention. For example, where the fluid source 838 is a gas supply it may be coupled to hose 851 thereby eliminating the need for a separate compressed gas supply, i.e., pump 845 . Further, a separate gas supply and vacuum pump may supply the backside pressure and vacuum conditions. While it is preferable to allow for both a backside pressure as well as a backside vacuum, a simplified embodiment may comprise a pump capable of supplying only a backside vacuum. However, as will be explained below, deposition uniformity may be improved where a backside pressure is provided during processing. Therefore, an arrangement such as the one described above including a vacuum ejector and a cross-over valve is preferred.
[0071] Referring now to FIGS. 12A and 14, a substantially circular ring-shaped manifold 846 is disposed in the annular recess 840 . The manifold 846 comprises a mounting rail 852 disposed between an inner shoulder 848 and an outer shoulder 850 . The mounting rail 852 is adapted to be at least partially inserted into the annular mounting channel 843 . A plurality of fluid outlets 854 formed in the manifold 846 provide communication between the inlets 842 and the bladder 836 . Seals 837 , such as O-rings, are disposed in the annular manifold channel 843 in alignment with the inlet 842 and outlet 854 and secured by the wafer holder plate 832 to ensure an airtight seal. Conventional fasteners (not shown) such as screws may be used to secure the manifold 846 to the wafer holder plate 832 via cooperating threaded bores (not shown) formed in the manifold 846 and the wafer holder plate 832 .
[0072] Referring now to FIG. 15, the bladder 836 is shown, in section, as an elongated substantially semi-tubular piece of material having annular lip seals 856 , or nodules, at each edge. In FIG. 12A, the lip seals 856 are shown disposed on the inner shoulder 848 and the outer shoulder 850 . A portion of the bladder 836 is compressed against the walls of the annular recess 840 by the manifold 846 which has a width slightly less (e.g. a few millimeters) than the annular recess 840 . Thus, the manifold 846 , the bladder 836 , and the annular recess 840 cooperate to form a fluid-tight seal. To prevent fluid loss, the bladder 836 is preferably comprised of some fluid impervious material such as silicon rubber or any comparable elastomer which is chemically inert with respect to the electrolyte and exhibits reliable elasticity. Where needed a compliant covering 857 may be disposed over the bladder 836 , as shown in FIG. 15, and secured by means of an adhesive or thermal bonding. The covering 857 preferably comprises an elastomer such as Viton™, buna rubber or the like, which may be reinforced by Kevlar™, for example. In one embodiment, the covering 857 and the bladder 836 comprise the same material. The covering 857 has particular application where the bladder 836 is liable to rupturing. Alternatively, the bladder 836 thickness may simply be increased during its manufacturing to reduce the likelihood of puncture.
[0073] The precise number of inlets 842 and outlets 854 may be varied according to the particular application without deviating from the present invention. For example, while FIG. 12 shows two inlets with corresponding outlets, an alternative embodiment could employ a single fluid inlet which supplies fluid to the bladder 836 .
[0074] In operation, the substrate 821 is introduced into the container body 802 by securing it to the lower side of the wafer holder plate 832 . This is accomplished by engaging the pumping system 159 to evacuate the space between the substrate 821 and the wafer holder plate 832 via port 841 thereby creating a vacuum condition. The bladder 836 is then inflated by supplying a fluid such as air or water from the fluid source 838 to the inlets 842 . The fluid is delivered into the bladder 836 via the manifold outlets 854 , thereby pressing the substrate 821 uniformly against the contacts of the cathode contact ring 466 . The electroplating process is then carried out. An electrolyte is then pumped into the process kit 420 toward the substrate 821 to contact the exposed substrate plating surface 820 . The power supply provides a negative bias to the substrate plating surface 820 via the cathode contact ring 466 . As the electrolyte is flowed across the substrate plating surface 820 , ions in the electrolytic solution are attracted to the surface 820 and deposit on the surface 820 to form the desired film.
[0075] Because of its flexibility, the bladder 836 deforms to accommodate the asperities of the substrate backside and contacts of the cathode contact ring 466 thereby mitigating misalignment with the conducting cathode contact ring 466 . The compliant bladder 836 prevents the electrolyte from contaminating the backside of the substrate 821 by establishing a fluid tight seal at a perimeter portion of a backside of the substrate 821 . Once inflated, a uniform pressure is delivered downward toward the cathode contact ring 466 to achieve substantially equal force at all points where the substrate 821 and cathode contact ring 466 interface. The force can be varied as a function of the pressure supplied by the fluid source 838 . Further, the effectiveness of the bladder assembly 470 is not dependent on the configuration of the cathode contact ring 466 . For example, while FIG. 12 shows a pin configuration having a plurality of discrete contact points, the cathode contact ring 466 may also be a continuous surface.
[0076] Because the force delivered to the substrate 821 by the bladder 836 is variable, adjustments can be made to the current flow supplied by the contact ring 466 . As described above, an oxide layer may form on the cathode contact ring 466 and act to restrict current flow. However, increasing the pressure of the bladder 836 may counteract the current flow restriction due to oxidation. As the pressure is increased, the malleable oxide layer is compromised and superior contact between the cathode contact ring 466 and the substrate 821 results. The effectiveness of the bladder 836 in this capacity may be further improved by altering the geometry of the cathode contact ring 466 . For example, a knife-edge geometry is likely to penetrate the oxide layer more easily than a dull rounded edge or flat edge.
[0077] Additionally, the fluid tight seal provided by the inflated bladder 836 allows the pump 845 to maintain a backside vacuum or pressure either selectively or continuously, before, during, and after processing. Generally, however, the pump 845 is run to maintain a vacuum only during the transfer of substrates to and from the electroplating process cell 400 because it has been found that the bladder 836 is capable of maintaining the backside vacuum condition during processing without continuous pumping. Thus, while inflating the bladder 836 , as described above, the backside vacuum condition is simultaneously relieved by disengaging the pumping system 859 , e.g., by selecting an OFF position on the cross-over valve 847 . Disengaging the pumping system 859 may be abrupt or comprise a gradual process whereby the vacuum condition is ramped down. Ramping allows for a controlled exchange between the inflating bladder 836 and the simultaneously decreasing backside vacuum condition. This exchange may be controlled manually or by computer.
[0078] As described above, continuous backside vacuum pumping while the bladder 836 is inflated is not needed and may actually cause the substrate 820 to buckle or warp leading to undesirable deposition results. It may, however, be desirable to provide a backside pressure to the substrate 820 in order to cause a “bowing” effect of the substrate to be processed. The inventors of the present invention have discovered that bowing results in superior deposition. Thus, pumping system 859 is capable of selectively providing a vacuum or pressure condition to the substrate backside. For a 200 mm wafer a backside pressure up to 5 psi is preferable to bow the substrate. Because substrates typically exhibit some measure of pliability, a backside pressure causes the substrate to bow or assume a convex shape relative to the upward flow of the electrolyte. The degree of bowing is variable according to the pressure supplied by pumping system 859 .
[0079] Those skilled in the art will readily recognize other embodiments which are contemplated by the present invention. For example, while FIG. 12A shows a preferred bladder 836 having a surface area sufficient to cover a relatively small perimeter portion of the substrate backside at a diameter substantially equal to the cathode contact ring 466 , the bladder assembly 470 may be geometrically varied. Thus, the bladder assembly may be constructed using more fluid impervious material to cover an increased surface area of the substrate 821 .
[0080] Referring back to FIG. 6, a cross sectional view of an electroplating process cell 400 , the wafer holder assembly 450 is positioned above the process kit 420 . The process kit 420 generally comprises a bowl 430 , a container body 472 , an anode assembly 474 and a filter 476 . Preferably, the anode assembly 474 is disposed below the container body 472 and attached to a lower portion of the container body 472 , and the filter 476 is disposed between the anode assembly 474 and the container body 472 . The container body 472 is preferably a cylindrical body comprised of an electrically insulative material, such as ceramics, plastics, plexiglass (acrylic), lexane, PVC, CPVC, and PVDF. Alternatively, the container body 472 can be made from a metal, such as stainless steel, nickel and titanium, which is coated with an insulating layer, such as teflon, PVDF, plastic, rubber and other combinations of materials that do not dissolve in the electrolyte and can be electrically insulated from the electrodes (i.e., the anode and cathode of the electroplating system). The container body 472 is preferably sized and adapted to conform to the wafer plating surface and the shape of the of a wafer being processed through the system, typically circular or rectangular in shape. One preferred embodiment of the container body 472 comprises a cylindrical ceramic tube having an inner diameter that has about the same dimension as or slightly larger than the wafer diameter. The inventors have discovered that the rotational movement typically required in typical electroplating systems is not required to achieve uniform plating results when the size of the container body conforms to about the size of the wafer plating surface.
[0081] An upper portion of the container body 472 extends radially outwardly to form an annular weir 478 . The weir 478 extends over the inner wall 446 of the electrolyte collector 440 and allows the electrolyte to flow into the electrolyte collector 440 . The upper surface of the weir 478 preferably matches the lower surface of the cathode contact ring 466 . Preferably, the upper surface of the weir 478 includes an inner annular flat portion 480 , a middle inclined portion 482 and an outer declined portion 484 . When a wafer is positioned in the processing position, the wafer plating surface is positioned above the cylindrical opening of the container body 472 , and a gap for electrolyte flow is formed between the lower surface of the cathode contact ring 466 and the upper surface of the weir 478 . The lower surface of the cathode contact ring 466 is disposed above the inner flat portion 480 and the middle inclined portion of the weir 478 . The outer declined portion 484 is sloped downwardly to facilitate flow of the electrolyte into the electrolyte collector 440 .
[0082] A lower portion of the container body 472 extends radially outwardly to form a lower annular flange 486 for securing the container body 472 to the bowl 430 . The outer dimension (i.e., circumference) of the annular flange 486 is smaller than the dimensions of the opening 444 and the inner circumference of the electrolyte collector 440 to allow removal and replacement of the process kit 420 from the electroplating process cell 400 . Preferably, a plurality of bolts 488 are fixedly disposed on the annular flange 486 and extend downwardly through matching bolt holes on the bowl 430 . A plurality of removable fastener nuts 490 secure the process kit 420 onto the bowl 430 . A seal 487 , such as an elastomer O-ring, is disposed between container body 472 and the bowl 430 radially inwardly from the bolts 488 to prevent leaks from the process kit 420 . The nuts/bolts combination facilitates fast and easy removal and replacement of the components of the process kit 420 during maintenance.
[0083] Preferably, the filter 476 is attached to and completely covers the lower opening of the container body 472 , and the anode assembly 474 is disposed below the filter 476 . A spacer 492 is disposed between the filter 476 and the anode assembly 474 . Preferably, the filter 476 , the spacer 492 , and the anode assembly 474 are fastened to a lower surface of the container body 472 using removable fasteners, such as screws and/or bolts. Alternatively, the filter 476 , the spacer 492 , and the anode assembly 474 are removably secured to the bowl 430 .
[0084] The anode assembly 474 preferably comprises a consumable anode that serves as a metal source in the electrolyte. Alternatively, the anode assembly 474 comprises a non-consumable anode, and the metal to be electroplated is supplied within the electrolyte from the electrolyte replenishing system 600 . As shown in FIG. 6, the anode assembly 474 is a self-enclosed module having a porous anode enclosure 494 preferably made of the same metal as the metal to be electroplated, such as copper. Alternatively, the anode enclosure 494 is made of porous materials, such as ceramics or polymeric membranes. A soluble metal 496 , such as high purity copper for electro-chemical deposition of copper, is disposed within the anode enclosure 494 . The soluble metal 496 preferably comprises metal particles, wires or a perforated sheet. The porous anode enclosure 494 also acts as a filter that keeps the particulates generated by the dissolving metal within the anode enclosure 494 . As compared to a non-consumable anode, the consumable (i.e., soluble) anode provides gas-generation-free electrolyte and minimizes the need to constantly replenish the metal in the electrolyte.
[0085] An anode electrode contact 498 is inserted into the anode enclosure 494 to provide electrical connection to the soluble metal 496 from a power supply. Preferably, the anode electrode contact 498 is made from a conductive material that is insoluble in the electrolyte, such as titanium, platinum and platinum-coated stainless steel. The anode electrode contact 498 extends through the bowl 430 and is connected to an electrical power supply. Preferably, the anode electrical contact 498 includes a threaded portion 497 for a fastener nut 499 to secure the anode electrical contact 498 to the bowl 430 , and a seal 495 , such as a elastomer washer, is disposed between the fastener nut 499 and the bowl 430 to prevent leaks from the process kit 420 .
[0086] The bowl 430 generally comprises a cylindrical portion 502 and a bottom portion 504 . An upper annular flange 506 extends radially outwardly from the top of the cylindrical portion 502 . The upper annular flange 506 includes a plurality of holes 508 that matches the number of bolts 488 from the lower annular flange 486 of the container body 472 . To secure the upper annular flange 506 of the bowl 430 and the lower annular flange 486 of the container body 472 , the bolts 488 are inserted through the holes 508 , and the fastener nuts 490 are fastened onto the bolts 488 . Preferably, the outer dimension (i.e., circumference) of the upper annular flange 506 is about the same as the outer dimension (i.e., circumference) of the lower annular flange 486 . Preferably, the lower surface of the upper annular flange 506 of the bowl 430 rests on a support flange of the mainframe 214 when the process kit 420 is positioned on the mainframe 214 .
[0087] The inner circumference of the cylindrical portion 502 accommodates the anode assembly 474 and the filter 476 . Preferably, the outer dimensions of the filter 476 and the anode assembly 474 are slightly smaller than the inner dimension of the cylindrical portion 502 to force a substantial portion of the electrolyte to flow through the anode assembly 474 first before flowing through the filter 476 . The bottom portion 504 of the bowl 430 includes an electrolyte inlet 510 that connects to an electrolyte supply line from the electrolyte replenishing system 220 . Preferably, the anode assembly 474 is disposed about a middle portion of the cylindrical portion 502 of the bowl 430 to provide a gap for electrolyte flow between the anode assembly 474 and the electrolyte inlet 510 on the bottom portion 504 .
[0088] The electrolyte inlet 510 and the electrolyte supply line are preferably connected by a releasable connector that facilitates easy removal and replacement of the process kit 420 . When the process kit 420 needs maintenance, the electrolyte is drained from the process kit 420 , and the electrolyte flow in the electrolyte supply line is discontinued and drained. The connector for the electrolyte supply line is released from the electrolyte inlet 510 , and the electrical connection to the anode assembly 474 is also disconnected. The head assembly 410 is raised or rotated to provide clearance for removal of the process kit 420 . The process kit 420 is then removed from the mainframe 214 , and a new or reconditioned process kit is replaced into the mainframe 214 .
[0089] Alternatively, the bowl 430 can be secured onto the support flange of the mainframe 214 , and the container body 472 along with the anode and the filter are removed for maintenance. In this case, the nuts securing the anode assembly 474 and the container body 472 to the bowl 430 are removed to facilitate removal of the anode assembly 474 and the container body 472 . New or reconditioned anode assembly 474 and container body 472 are then replaced into the mainframe 214 and secured to the bowl 430 .
[0090] [0090]FIG. 16 is a schematic diagram of an electrolyte replenishing system 600 . The electrolyte replenishing system 600 generally comprises a main electrolyte tank 602 , one or more filter tanks 604 , one or more source tanks 606 , one or more fluid pumps 608 . The electrolyte replenishing system 600 is connected to a controller 610 for controlling the composition of the electrolyte and the operation of the electrolyte replenishing system 600 . Preferably, the controller 610 is independently operable but integrated with the control system 222 of the electroplating system platform 200 .
[0091] The electrolyte replenishing system 600 provides the electrolyte to the electroplating process cells for the electroplating process. The electrolyte replenishing system 600 as shown in FIG. 16 is the same as the electrolyte replenishing system 220 as shown in FIGS. 2 and 3. The main electrolyte tank 602 includes an electrolyte supply line 612 that is connected to each of the electroplating process cells through one or more fluid pumps 608 . The electrolyte replenishing system 600 includes a plurality of source tanks that are connected to the main tank 602 to supply the chemicals needed for composing the electrolyte. The source tanks typically include a deionized water source tank and copper sulfate source tank for composing the electrolyte. The deionized water source tank preferably also provides deionized water to the system for cleaning the system during maintenance.
[0092] The electrolyte replenishing system 600 also includes a plurality of filter tanks 604 connected to the main tank 602 . Preferably, an electrolyte return line 614 is connected between each of the process cells and one or more filter tanks 604 . The filter tanks 604 remove the undesired contents in the used electrolyte before returning the electrolyte to the main tank 602 for re-use. The main tank 602 is preferably connected to one or more of the filter tanks 604 to facilitate re-circulation and filtration of the electrolyte in the main tank 602 through the filter tanks 604 . By re-circulating the electrolyte from the main tank 602 through the filter tanks 604 , the undesired contents in the electrolyte are continuously removed by the filter tanks 604 .
[0093] Preferably, the electrolyte replenishing system 600 includes a chemical analyzer 616 that provides real time chemical analysis of the chemical composition of the electrolyte. The information from the chemical analyzer 616 is inputted to the controller 610 which uses the information to provide real time adjustment of the source chemical replenishment rates to maintain constant chemical composition of the electrolyte throughout the electroplating process. Additionally, the chemical analyzer preferably provides an analysis of organic and inorganic constituents of the electrolyte.
[0094] The electrolyte replenishing system 600 preferably also includes one or more additional tanks for storage of chemicals for wafer cleaning system, such as the SRD station. The electrolyte replenishing system 600 also includes an electrolyte waste drain 620 connected to an electrolyte waste disposal system 622 for safe disposal of used electrolytes, chemicals and other fluids used in the electroplating system. Preferably, the electroplating cells include a direct line connection to the electrolyte waste drain or the electrolyte waste disposal system to drain the electroplating cell without returning the electrolyte through the electrolyte replenishing system 600 . The electrolyte replenishing system 600 preferably also includes a bleed off connection to bleed off excess electrolyte to the electrolyte waste drain. Optionally, the electrolyte replenishing system 600 includes connections to additional or external electrolyte processing system to provide additional electrolyte supplies to the electroplating system. Preferably, the electrolyte replenishing system 600 includes double-contained piping for hazardous material connections to provide safe transport of the chemicals throughout the system. The electrolyte replenishing system 600 preferably controls the temperature of the electrolyte through a heat exchanger 624 or a heater/chiller disposed in thermal connection with the main tank. The heat exchanger 624 is connected to and operated by the controller 610 .
[0095] [0095]FIG. 17 is a cross sectional view of a rapid thermal anneal chamber according to the invention. The rapid thermal anneal (RTA) chamber 211 is preferably connected to the loading station 210 , and substrates are transferred into and out of the RTA chamber 211 by the loading station transfer robot 228 . The electroplating system, as shown in FIGS. 2 and 3, preferably comprises two RTA chambers 211 disposed on opposing sides of the loading station 210 , corresponding to the symmetric design of the loading station 210 . Thermal anneal process chambers are generally well known in the art, and rapid thermal anneal chambers are typically utilized in substrate processing systems to enhance the properties of the deposited materials. The invention contemplates utilizing a variety of thermal anneal chamber designs, including hot plate designs and heat lamp designs, to enhance the electroplating results. One particular thermal anneal chamber useful for the present invention is the WxZ chamber available from Applied materials, Inc., located in Santa Clara, Calif. Although the invention is described using a hot plate rapid thermal anneal chamber, the invention contemplates application of other thermal anneal chambers as well.
[0096] The RTA chamber 211 generally comprises an enclosure 902 , a heater plate 904 , a heater 907 and a plurality of substrate support pins 906 . The enclosure 902 includes a base 908 , a sidewall 910 and a top 912 . Preferably, a cold plate 913 is disposed below the top 912 of the enclosure. Alternatively, the cold plate is integrally formed as part of the top 912 of the enclosure. Preferably, a reflector insulator dish 914 is disposed inside the enclosure 902 on the base 908 . The reflector insulator dish 914 is typically made from a material such as quartz, alumina, or other material that can withstand high temperatures (i.e., greater than about 500° C.), and act as a thermal insulator between the heater 907 and the enclosure 902 . The dish 914 may also be coated with a reflective material, such as gold, to direct heat back to the heater plate 906 .
[0097] The heater plate 904 preferably has a large mass compared to the substrate being processed in the system and is preferably fabricated from a material such as silicon carbide, quartz, or other materials that do not react with any ambient gases in the RTA chamber 211 or with the substrate material. The heater 907 typically comprises a resistive heating element or a conductive/radiant heat source and is disposed between the heated plate 906 and the reflector insulator dish 914 . The heater 907 is connected to a power source 916 which supplies the energy needed to heat the heater 907 . Preferably, a thermocouple 920 is disposed in a conduit 922 , disposed through the base 908 and dish 914 , and extends into the heater plate 904 . The thermocouple 920 is connected to a controller (i.e., the system controller described below) and supplies temperature measurements to the controller. The controller then increases or decreases the heat supplied by the heater 907 according to the temperature measurements and the desired anneal temperature.
[0098] The enclosure 902 preferably includes a cooling member 918 disposed outside of the enclosure 902 in thermal contact with the sidewall 910 to cool the enclosure 902 . Alternatively, one or more cooling channels (not shown) are formed within the sidewall 910 to control the temperature of the enclosure 902 . The cold plate 913 disposed on the inside surface of the top 912 cools a substrate that is positioned in close proximity to the cold plate 913 .
[0099] The RTA chamber 211 includes a slit valve 922 disposed on the sidewall 910 of the enclosure 902 for facilitating transfers of substrates into and out of the RTA chamber. The slit valve 922 selectively seals an opening 924 on the sidewall 910 of the enclosure that communicates with the loading station 210 . The loading station transfer robot 228 (see FIG. 2) transfers substrates into and out of the RTA chamber through the opening 924 .
[0100] The substrate support pins 906 preferably comprise distally tapered members constructed from quartz, aluminum oxide, silicon carbide, or other high temperature resistant materials. Each substrate support pin 906 is disposed within a tubular conduit 926 , preferably made of a heat and oxidation resistant material, that extends through the heater plate 904 . The substrate support pins 906 are connected to a lift plate 928 for moving the substrate support pins 906 in a uniform manner. The lift plate 928 is attached to an to an actuator 930 , such as a stepper motor, through a lift shaft 932 that moves the lift plate 928 to facilitate positioning of a substrate at various vertical positions within the RTA chamber. The lift shaft 932 extends through the base 908 of the enclosure 902 and is sealed by a sealing flange 934 disposed around the shaft.
[0101] To transfer a substrate into the RTA chamber 211 , the slit valve 922 is opened, and the loading station transfer robot 228 extends its robot blade having a substrate positioned thereon through the opening 924 into the RTA chamber. The robot blade of the loading station transfer robot 228 positions the substrate in the RTA chamber above the heater plate 904 , and the substrate support pins 906 are extended upwards to lift the substrate above the robot blade. The robot blade then retracts out of the RTA chamber, and the slit valve 922 closes the opening. The substrate support pins 906 are then retracted to lower the substrate to a desired distance from the heater plate 904 . Optionally, the substrate support pins 906 may retract fully to place the substrate in direct contact with the heater plate.
[0102] Preferably, a gas inlet 936 is disposed through the sidewall 910 of the enclosure 902 to allow selected gas flow into the RTA chamber 211 during the anneal treatment process. The gas inlet 936 is connected to a gas source 938 through a valve 940 for controlling the flow of the gas into the RTA chamber 211 . A gas outlet 942 is preferably disposed at a lower portion of the sidewall 910 of the enclosure 902 to exhaust the gases in the RTA chamber and is preferably connected to a relief/check valve 944 to prevent backstreaming of atmosphere from outside of the chamber. Optionally, the gas outlet 942 is connected to a vacuum pump (not shown) to exhaust the RTA chamber to a desired vacuum level during an anneal treatment.
[0103] According to the invention, a substrate is annealed in the RTA chamber 211 after the substrate has been electroplated in the electroplating cell and cleaned in the SRD station. Preferably, the RTA chamber 211 is maintained at about atmospheric pressure, and the oxygen content inside the RTA chamber 211 is controlled to less than about 100 ppm during the anneal treatment process. Preferably, the ambient environment inside the RTA chamber 211 comprises nitrogen (N 2 ) or a combination of nitrogen (N 2 ) and less than about 4% hydrogen (H 2 ), and the ambient gas flow into the RTA chamber 211 is maintained at greater than 20 liters/min to control the oxygen content to less than 100 ppm. The electroplated substrate is preferably annealed at a temperature between about 200° C. and about 450° C. for between about 30 seconds and 30 minutes, and more preferably, between about 250° C. and about 400° C. for between about 1 minute and 5 minutes. Rapid thermal anneal processing typically requires a temperature increase of at least 50° C. per second. To provide the required rate of temperature increase for the substrate during the anneal treatment, the heater plate is preferably maintained at between about 350° C. and about 450° C., and the substrate is preferably positioned at between about 0 mm (i.e., contacting the heater plate) and about 20 mm from the heater plate for the duration of the anneal treatment process. Preferably, a control system 222 controls the operation of the RTA chamber 211 , including maintaining the desired ambient environment in the RTA chamber and the temperature of the heater plate.
[0104] After the anneal treatment process is completed, the substrate support pins 906 lift the substrate to a position for transfer out of the RTA chamber 211 . The slit valve 922 opens, and the robot blade of the loading station transfer robot 228 is extended into the RTA chamber and positioned below the substrate. The substrate support pins 906 retract to lower the substrate onto the robot blade, and the robot blade then retracts out of the RTA chamber. The loading station transfer robot 228 then transfers the processed substrate into the cassette 232 for removal out of the electroplating processing system. (see FIGS. 2 and 3).
[0105] Referring back to FIG. 2, the electroplating system platform 200 includes a control system 222 that controls the functions of each component of the platform. Preferably, the control system 222 is mounted above the mainframe 214 and comprises a programmable microprocessor. The programmable microprocessor is typically programmed using a software designed specifically for controlling all components of the electroplating system platform 200 . The control system 222 also provides electrical power to the components of the system and includes a control panel 223 that allows an operator to monitor and operate the electroplating system platform 200 . The control panel 223 , as shown in FIG. 2, is a stand-alone module that is connected to the control system 222 through a cable and provides easy access to an operator. Generally, the control system 222 coordinates the operations of the loading station 210 , the RTA chamber 211 , the SRD station 212 , the mainframe 214 and the processing stations 218 . Additionally, the control system 222 coordinates with the controller of the electrolyte replenishing system 600 to provide the electrolyte for the electroplating process.
[0106] The following is a description of a typical wafer electroplating process sequence through the electroplating system platform 200 as shown in FIG. 2. A wafer cassette containing a plurality of wafers is loaded into the wafer cassette receiving areas 224 in the loading station 210 of the electroplating system platform 200 . A loading station transfer robot 228 picks up a wafer from a wafer slot in the wafer cassette and places the wafer in the wafer orientor 230 . The wafer orientor 230 determines and orients the wafer to a desired orientation for processing through the system. The loading station transfer robot 228 then transfers the oriented wafer from the wafer orientor 230 and positions the wafer in one of the wafer slots in the wafer pass-through cassette 238 in the SRD station 212 . The mainframe transfer robot 242 picks up the wafer from the wafer pass-through cassette 238 and positions the wafer for transfer by the flipper robot 248 . The flipper robot 248 rotates its robot blade below the wafer and picks up wafer from mainframe transfer robot blade. The vacuum suction gripper on the flipper robot blade secures the wafer on the flipper robot blade, and the flipper robot flips the wafer from a face up position to a face down position. The flipper robot 248 rotates and positions the wafer face down in the wafer holder assembly 450 . The wafer is positioned below the wafer holder 464 but above the cathode contact ring 466 . The flipper robot 248 then releases the wafer to position the wafer into the cathode contact ring 466 . The wafer holder 464 moves toward the wafer and the vacuum chuck secures the wafer on the wafer holder 464 . The bladder assembly 470 on the wafer holder assembly 450 exerts pressure against the wafer backside to ensure electrical contact between the wafer plating surface and the cathode contact ring 466 .
[0107] The head assembly 452 is lowered to a processing position above the process kit 420 . At this position the wafer is below the upper plane of the weir 478 and contacts the electrolyte contained in the process kit 420 . The power supply is activated to supply electrical power (i.e., voltage and current) to the cathode and the anode to enable the electroplating process. The electrolyte is typically continually pumped into the process kit during the electroplating process. The electrical power supplied to the cathode and the anode and the flow of the electrolyte are controlled by the control system 222 to achieve the desired electroplating results.
[0108] After the electroplating process is completed, the head assembly 410 raises the wafer holder assembly and removes the wafer from the electrolyte. The vacuum chuck and the bladder assembly of the wafer holder release the wafer from the wafer holder, and the wafer holder is raised to allow the flipper robot blade to pick up the processed wafer from the cathode contact ring. The flipper robot rotates the flipper robot blade above the backside of the processed wafer in the cathode contact ring and picks up the wafer using the vacuum suction gripper on the flipper robot blade. The flipper robot rotates the flipper robot blade with the wafer out of the wafer holder assembly, flips the wafer from a face-down position to a face-up position, and positions the wafer on the mainframe transfer robot blade. The mainframe transfer robot then transfers and positions the processed wafer above the SRD module 236 . The SRD wafer support lifts the wafer, and the mainframe transfer robot blade retracts away from the SRD module 236 . The wafer is cleaned in the SRD module using deionized water or a combination of deionized water and a cleaning fluid as described in detail above. The wafer is then positioned for transfer out of the SRD module. The loading station transfer robot 228 picks up the wafer from the SRD module 236 and transfers the processed wafer into the RTA chamber 211 for an anneal treatment process to enhance the properties of the deposited materials. The annealed wafer is then transferred out of the RTA chamber 211 by the loading station robot 228 and placed back into the wafer cassette for removal from the electroplating system. The above-described sequence can be carried out for a plurality of wafers substantially simultaneously in the electroplating system platform 200 of the present invention. Also, the electroplating system according to the invention can be adapted to provide multi-stack wafer processing.
[0109] While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims which follow.
|
The present invention generally provides an electro-chemical deposition system that is designed with a flexible architecture that is expandable to accommodate future designs rules and gap fill requirements and provides satisfactory throughput to meet the demands of other processing systems. The electro-chemical deposition system generally comprises a mainframe having a mainframe wafer transfer robot, a loading station disposed in connection with the mainframe, a rapid thermal anneal chamber disposed adjacent the loading station, one or more processing cells disposed in connection with the mainframe, and an electrolyte supply fluidly connected to the one or more electrical processing cells. One aspect of the invention provides a post electrochemical deposition treatment, such as a rapid thermal anneal treatment, for enhancing deposition results. Preferably, the electro-chemical deposition system includes a system controller adapted to control the electro-chemical deposition process and the components of the electro-chemical deposition system, including the rapid thermal anneal chamber disposed adjacent the loading station.
| 7
|
This application claims the benefit of U.S. provisional application 61/706,346 filed on Sep. 27, 2012, the complete disclosure of which is hereby incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
The present invention relates to an intravaginal tampon for feminine hygiene. In particular, it relates to methods for producing such a tampon having relatively deep, penetrating grooves in which adjacent penetrating jaws pass through the same tampon press space during manufacture and to an apparatus useful in making such a tampon as well as the tampons made therewith.
BACKGROUND OF THE INVENTION
Devices for intravaginally capturing and storing bodily fluid are commercially available and known in the literature. Intravaginal tampons for feminine hygiene are the most common example of such devices. Commercially available tampons are generally compressed cylindrical masses of absorbent fibers that may be contained by an absorbent or nonabsorbent cover layer.
The tampon is inserted into the human vagina and retained there for a time for the purpose of capturing and storing intravaginal bodily fluids, most commonly menstrual fluid. As intravaginal bodily fluid contacts the tampon, it should be absorbed and retained by the absorbent material of the tampon. After a time, the tampon and its retained fluid is removed and disposed, and if necessary, another tampon is inserted.
A drawback often encountered with commercially available tampons is the tendency toward premature failure, which may be defined as bodily fluid leakage from the vagina while the tampon is in place and before the tampon is completely saturated with the bodily fluid. The patent art typically describes a problem believed to occur that an unexpanded, compressed tampon is unable to immediately absorb fluid. Therefore, it presumes that premature leakage may occur when bodily fluid contacts a portion of the compressed tampon, and the fluid is not readily absorbed.
One way to prevent premature leakage from occurring is to provide designed pathways for fluid moving along the outer tampon surface. While this increase to the pathways may improve the fluid absorption, adding grooves during the manufacturing process can raise process issues. The prior art is replete with examples of attempts to incorporate grooves into tampons. Often new steps are added to an already complicated manufacturing process or the process is not fully described.
Friese et al., EP 0422660 B2, discloses an apparatus for producing a tampon with longitudinal grooves. The apparatus for making the tampon includes two groups of dies arranged in a plane perpendicular to the press axis. The first group of dies form press segments and the second group of dies form sliding plates. Each of the dies has press cutters projecting from the faces. The blank is pressed into a preform having a core with high compression and longitudinal ribs separated by grooves. The dies do not include a surface for forming shoulders.
Schoelling, US 2002-0151859 A1, discloses an apparatus for producing tampons having spirally shaped, pressed longitudinal grooves. The apparatus has press jaws of substantially equal dimensions which are arranged in a star formation with respect to the press axis. The jaws can be moved synchronously between open and closed positions. Each press jaw has a stepped pressing surface including a pressing blade and a pressing shoulder. The area of the pressing shoulder is great than the area of the pressing blade. The pressing blade and pressing shoulder can extend over a circumferential angle α of between 80 to 150° in the closed or pressing position. The press jaws are slightly retracted to give clearance when the preform is ejected from the press.
Van Ingelgem et al., EP 1547555 B1 purports to disclose an apparatus for manufacturing tampons with at least three press jaws, each press jaw having a penetrating segment for penetrating the absorbent material and pressing shoulder. The median of the penetrating segment diverges from the radius of that penetrating segment when in the press. The median of the penetrating segment is the straight line drawn in a cross section of the penetrating segment, through its tip and the midpoint of its base. One press jaw may comprise either a penetrating segment or a pressing shoulder, or a combination of one penetrating segment and pressing shoulders arranged at either or both sides of the penetrating segment. If the penetrating segment and pressing shoulders are fixed to separate press jaws, it is preferably that they press simultaneously. The press jaws, in particular, the penetrating segments can have a straight, sinusoidal, spiral or helical shape in the longitudinal direction to form essentially straight, sinusoidal, spiral, or helical grooves in the axial direction of the tampon. The resultant tampon has at least three ribs, in transverse cross-section, has a median at least partially diverging from the radius where the median of the rib is the line drawn through the midpoint of a series of arc lines, bound by the edges of the rib, wherein the arcs have a common center which is the midpoint of the X-X cross-section of the tampon.
Schmidt, EP 1459720 B1, purports to disclose increasing the surface area of a tampon by utilizing grooves that are formed in a wave shape. While multiple examples are shown, including wavy grooves with angled points, this publication does not disclose specifics on how to manufacture the tampons. In particular, the publication does not include specifics about compression, the press jaws or how the preform or tampon is ejected from the press.
Ruhlmann, WO 2009/129910 A1, purports to disclose a tampon having at least one first surface groove and at least one second surface groove that crosses the first surface groove along their path between a proximal end and a distal end of the tampon. However, the disclosure fails to teach how the crossing grooves are formed, especially in a commercially-feasible manufacturing process and/or with a cover.
Fung, US 2011-0092940 A1, discloses an intravaginal tampon formed of compressed material and has an outer surface with at least two segmented grooves are formed therein, and each segmented groove is separated from and spaced at a distance from an adjacent segmented groove. Each segmented groove has at least one substantially longitudinal segment and at least one accumulator segment. The arrangement of the segments provides a pooling region to impede bodily fluid flow along the outer surface of the tampon.
While the above examples describe tampons with grooves or the process for making such tampon, these tampons do not have visually distinct zones with different bodily fluid handling characteristics. In addition, the processes do not show how to make such a unique intravaginal tampon.
Further, the above examples fail to provide a tampon having intersecting longitudinal groove segments that penetrate deeply to provide fluid access into the absorbent structure and to provide column strength. Such penetrating grooves also provide a place into which to tuck or fold excess liquid permeable cover material resulting from tampon blank compression with a generally (non-stretchy) coverstock.
SUMMARY OF THE INVENTION
It has been discovered that intersecting groove segments can form deeply penetrating grooves in substantially cylindrical tampons to provide the benefits of deep grooves to transfer fluid into the tampon core and the benefits of intersecting grooves on the surface of the tampon.
In one aspect of the invention, a process of forming a compressed tampon pledget having substantially longitudinal grooves and a predetermined finished diameter includes inserting a tampon blank substantially enclosed in a liquid permeable cover into a press cavity, performing an initial compression step by moving into the press cavity toward the central press axis a plurality of longitudinal penetrating dies having pressing faces, backing the penetrating dies away from the central press axis, performing a second compression step, transferring the compressed tampon pledget to a cylindrical carrier having an internal diameter less than the predetermined finished diameter, and enclosing the compressed tampon pledget in a primary package having an internal diameter substantially equal to predetermined finished diameter thereby allowing the compressed tampon pledget to expand to the predetermined finished diameter. The press cavity has a central press axis and a plurality of elongate press dies disposed about the central press axis, wherein the tampon blank has a longitudinal axis that is disposed substantially along the central press axis. The pressing faces of the penetrating dies correspond to a plurality of longitudinal groove segments in the desired compressed tampon pledget, and at least one first penetrating die has a pressing face corresponding to a desired first groove segment shape and at least one second penetrating die has a pressing face corresponding to a second groove segment shape. The initial compression step produces a preform that has a plurality of substantially longitudinal grooves interspaced with a plurality of substantially longitudinal ribs. The first and second groove segment shapes combine to provide a groove form on the outer surface of the compressed tampon pledget, wherein the groove form has an intersection proximate to one end of the compressed tampon pledget. The pressing faces of the first and second penetrating dies are positioned at a closed position having a clear distance from the central press axis that is less than the predetermined finished diameter in the initial compression step. The pressing face of the first penetrating die extends longitudinally beyond the pressing face of the second penetrating die toward the end of the compressed tampon pledget whereby the first and second penetrating die pass through the same space within the press to form the groove form. The second compression step includes applying to the substantially longitudinal ribs of the preform a radial pressure directed toward the central press axis to provide a compressed tampon pledget of reduced diameter relative to the preform.
In another aspect, the present invention relates to an intravaginal tampon for feminine hygiene including a generally cylindrical absorbent pledget and a withdrawal element operatively connected to the generally cylindrical pledget proximate to the withdrawal end thereof. The absorbent pledget has a length, a longitudinal axis, an insertion end, and a withdrawal end. It includes a mass of fibers compressed into a self sustaining shape and a sheet-like fluid-permeable cover substantially enclosing the mass of fibers. The absorbent pledget has at least one groove form on the outer surface of the compressed tampon pledget, wherein the groove form has a turn comprising an intersection of at least two groove segments having a depth of at least about 0.7 mm proximate to one end of the compressed tampon pledget.
In yet another aspect, the present invention relates to an apparatus for manufacturing an intravaginal tampon for feminine hygiene. The apparatus includes a tampon press, a cylindrical carrier, and means to enclose the compressed tampon pledget in a primary package having an internal diameter substantially equal to a predetermined finished diameter. The press has a central press axis and it includes a plurality of elongate press dies disposed about central press axis to form a press cavity. The elongate press dies include a plurality of longitudinal penetrating dies having pressing faces corresponding to a plurality of longitudinal groove segments in a desired compressed tampon pledget. At least one of the press dies is a first penetrating die having a pressing shape corresponding to a desired first groove segment shape and at least one other of the press dies is a second penetrating die having a pressing face corresponding to a second groove segment shape. The first groove segment shape and the second groove segment shape combine to form a groove form on a tampon formed in the press. In addition, the pressing face of the first penetrating die extends longitudinally beyond the pressing face of the second penetrating die toward an end of the of the press cavity. Thus, the first and second penetrating dies are capable of passing through the same space within the press to form the groove form. The press also includes a control mechanism to control movement of the elongate press dies into and out of the press cavity.
Other aspects and features of the present invention will become apparent in those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view of one embodiment of a tampon according to the present invention.
FIG. 2 is a side view of another embodiment of a tampon according to the present invention.
FIG. 3 is a side view of a third embodiment of a tampon according to the present invention.
FIG. 4 is a side view of a fourth embodiment of a tampon according to the present invention.
FIG. 5 is a side view of a fifth embodiment of a tampon according to the present invention.
FIG. 6 is a side view of a sixth embodiment of a tampon according to the present invention.
FIG. 7 is a perspective view of a press having a single cam useful in forming tampons of the present invention; the cam is partially broken away, and some of the press elements have been removed for increased clarity of the illustrated press elements.
FIG. 7A is a side view of the central portion of the press of FIG. 7 including the press dies and central cavity; outer portions of the cam and other press elements are broken away for increased clarity of the central press portion.
FIG. 8 is perspective view of four of the press dies of the press of FIG. 7 .
FIG. 9 is cross-section of the central portion of the press of FIG. 7A along line (D-D) in an open position; outer portions of the press elements are broken away for increased clarity of the central press portion.
FIG. 10 is a cross-section of the central portion of the press of FIG. 7 proximate the notch during an initial compression step; outer portions of the press elements are broken away for increased clarity of the central press portion.
FIG. 11 is an enlarged cross-section view of the press of FIG. 10 clearly showing the penetrating die tips crossing during an initial compression step; the remaining press elements are broken away.
FIG. 12 is an enlarged perspective view of the press of FIG. 11 ; the remaining press elements are broken away.
FIG. 13 is cross-section view of the central portion of the press of FIG. 7A along line (D-D) during an ejection step; outer portions of the press elements are broken away for increased clarity of the central press portion.
FIG. 14 is an end view of the press of FIG. 13 in the ejection position.
FIG. 15 is a longitudinal cross-section of the press of FIG. 13 , during an ejection step.
FIG. 16 is a side elevation of a compressed tampon pledget prior to finishing the insertion end and packaging.
FIG. 17 is cross-section view of the central portion of an alternative press during an initial compression step.
FIG. 18 is cross-section view of the press of FIG. 17 during an ejection step showing penetrating dies capable of guiding the compressed tampon pledget from the press cavity.
FIG. 19 is a line view of the pressing faces of three penetrating dies useful to form the tampon of FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As used herein the specification and the claims, the term “groove” and variants thereof relate to an indention into the surface of the tampon. For clarification, grooves may be “penetrating grooves”, extending at least 0.7 mm (or 10% of the radius, whichever is greater) into the tampon or they may be “shallow grooves”, primarily surface indentations without significant penetration (of not more than 0.7 mm, not more than 10% of the radius) into the tampon body. Regions between grooves may take the form of ribs.
As used herein the specification and the claims, the term “groove form” and variants thereof relates to a groove or combination of groove segments that are connected in a visibly identifiable manner to provide a unique detached feature at least on the surface of the tampon pledget.
As used herein the specification and the claims, the term “turn” and variants thereof relates to a portion of the groove form in which the groove and/or groove elements reverse(s) upon itself/themselves in a substantially U-shaped or a substantially V-shaped configuration. A “turn” can also have a generally linear extension from the intersection, such as a substantially Y-shaped configuration.
As used herein the specification and the claims, the term “major axis” and variants thereof relating to the groove form is defined by the shortest line connecting the most distant points of the groove form. Generally, this major axis will pass through at least one turn proximate to one end of the pledget.
As used herein the specification and the claims, the term “longitudinal axis” and variants thereof relate to an axis that runs from the insertion end to the withdrawal end substantially through the center of the tampon.
As used in the specification and the claims, the term “self sustaining shape” and variants thereof relate to a tampon pledget that is compressed and/or shaped to assume a general shape and size that is dimensionally stable. For example, a digital tampon that has a self-sustaining shape will generally maintain its shape after a primary package or overwrap is removed and will generally maintain such shape for vaginal insertion. It will be recognized that the tampon is intended to absorb bodily fluids, and may substantially change shape during use as it absorbs such fluids.
As used in the specification and the claims, the term “pledget” and variants thereof relate to a pad or a compress of absorbent material such as fibers designed to absorb bodily fluids.
As used in the specification and the claims, the term “oriented substantially longitudinally” and variants thereof relate to a groove or a groove segment or a groove form that has a helix angle of greater than 45°.
As used in the specification and the claims, the term “fiber density” and variants thereof relate to the relative proportion of fibers to void space in a given volume of the fibrous structure.
The present invention relates to a tampon with reduced opportunity for bodily fluid to flow along the surface without being absorbed into the tampon pledget. This is accomplished by providing at least two detached groove forms each having a generally longitudinal orientation, a length (measured along the groove) that is at least 150% of the length of the pledget, and a turn proximate to at least one of an insertion end and a withdrawal end. The detached groove forms provide visually distinct zones with different bodily fluid handling characteristics. In addition, the turn proximate to at least one end of the tampon provides at least two groove paths for the fluid to follow to be distributed to different portions of the tampon pledget. Thus, not only does the present invention provide tampons with a plurality of grooves, recognized by the prior art as providing improved fluid handling characteristics, but it also provides either fully or partially closed absorption zones that visually communicate functional benefits to the user, including absorbent reservoirs to better contain bodily fluids in the tampon.
Referring to FIG. 1 , an intravaginal tampon 10 for feminine hygiene includes a generally cylindrical absorbent pledget 20 and a withdrawal element 30 extending therefrom. The pledget 20 has a longitudinal axis 21 , an insertion end 22 (which may terminate in a dome 23 ), and a withdrawal end 24 . The pledget includes a mass of fibers compressed into a self sustaining shape and a sheet-like fluid-permeable cover 25 (such as an apertured film cover) substantially enclosing the mass of fibers. The withdrawal element 30 , such as a string, is operatively connected to and extends from the pledget 20 proximate to the withdrawal end 24 thereof.
The pledget 20 includes a plurality of detached groove forms 40 arranged about the outer surface of the pledget 20 . In embodiment of FIG. 1 , the detached groove forms 40 each comprise a pair of wavy groove segments 41 , 42 that intersect to create a turn 43 proximate to the insertion end 22 of the pledget 20 and are separate proximate to the withdrawal end 24 .
In the embodiment of FIG. 2 , additional longitudinal grooves 44 are disposed between detached groove forms 40 .
The embodiment of FIG. 3 is similar to the embodiment of FIG. 1 . However, in the embodiment of FIG. 3 , the turn 43 is proximate to the withdrawal end 24 .
The embodiment of FIG. 4 is similar to the embodiment of FIG. 1 . However, in the embodiment of FIG. 4 , an additional longitudinal groove segment 45 intersects with groove segment 42 to form a second turn 43 proximate to the withdrawal end 24 . This forms a substantially inverted “N-shaped” detached groove form.
In the embodiment of FIG. 5 , the detached groove forms 40 ′ each comprise a pair of groove segments 41 ′, 42 ′ that intersect to create a turn 43 ′ proximate to both the insertion end 22 and the withdrawal end 24 of the pledget 20 to provide discrete surface zones 46 bounded by the encircling groove forms 40 ′.
In the embodiment of FIG. 6 , additional longitudinal grooves 44 are disposed between detached groove forms 40 ′.
Again the groove forms may comprise a plurality of groove segments. These groove segments may have a configuration that is a straight line, a plurality of linked angled segments (such as a saw tooth waveform or a square waveform), a plurality of curved segments (such as a sinusoidal waveform), and combinations thereof.
The configuration of the groove segments may differ between groove forms, or they may be the same. The configuration of groove segments within each groove form may also be the same or different. Additional grooves, including longitudinal grooves 44 , may be configured similarly to or distinct from each other and the configuration of the groove segments making up the groove forms 40 .
The absorbent pledget includes a mass of fibers compressed into a self sustaining shape. The pledget may also include additional absorbent materials such as foam, superabsorbent, hydrogels, and the like. Preferred absorbent material for the present invention includes foam and fiber. Absorbent foams may include hydrophilic foams, foams which are readily wetted by aqueous fluids as well as foams in which the cell walls that form the foam themselves absorb fluid.
Preferably, the fibers employed in the formation of the absorbent body include regenerated cellulosic fiber, natural fibers and synthetic fibers. Preferably, the materials employed in the formation of a tampon according to the present invention include fiber, foam, hydrogels, wood pulp, superabsorbents, and the like. A useful, non-limiting list of useful absorbent body fibers includes natural fibers such as cotton, wood pulp, jute, and the like; and processed fibers such as regenerated cellulose, cellulose nitrate, cellulose acetate, rayon, polyester, polyvinyl alcohol, polyolefin, polyamine, polyamide, polyacrylonitrile, and the like. Other fibers in addition to the above fibers may be included to add desirable characteristics to the absorbent body. Preferably, tampon fibers are rayon, cotton, or blends thereof, and more preferably, the fibers are rayon. The fibers may have any useful cross-section.
Fiber cross-sections include multi-limbed and non-limbed. Multilimbed, regenerated cellulosic fibers have been commercially available for a number of years. These fibers are known to possess increased specific absorbency over non-limbed fibers. A commercial example of these fibers is the Galaxy® multilimbed viscose rayon fibers available from Kelheim Fibres GmbH, Kelheim, Germany. These fibers are described in detail in Wilkes et al., U.S. Pat. No. 5,458,835, the disclosure of which is hereby incorporated by reference. Preferably, the fibers include hydrophilic fibers, and more preferably, the fibers include absorbent fibers, i.e., the individual fibers, themselves, absorb fluid. A useful, non-limiting list of useful tampon fibers includes natural fibers such as cotton, wood pulp, jute, hemp, and the like; and processed fibers such as regenerated cellulose, cellulose nitrate, cellulose acetate, rayon, polyester, polyvinyl alcohol, polyolefin, polyamine, polyamide, polyacrylonitrile, and the like. Other fibers in addition to the above fibers may be included to add desirable characteristics to the absorbent body. For example, hydrophobic fibers may be used in outer surfaces of the tampon to reduce surface wetness and hydrophilic fibers may be used to increase the rate of fluid transport into and throughout the body. Preferably, the tampon fibers are rayon or cotton, and more preferably, the fibers are rayon. The fibers may have any useful cross-section.
The pledget includes a mass of fibers substantially enclosed by a sheet-like cover material fluid-permeable cover. Thus, the cover encloses a majority of the outer surface of the tampon. This may be achieved as disclosed in Friese, U.S. Pat. No. 4,816,100, the disclosure of which is herein incorporated by reference. In addition, either or both ends of the tampon may be enclosed by the cover. Of course, for processing or other reasons, some portions of the surface of the tampon may be free of the cover. For example, the insertion end of the tampon and a portion of the cylindrical surface adjacent this end may be exposed, without the cover to allow the tampon to more readily accept fluids.
The cover can ease the insertion of the tampon into the body cavity and can reduce the possibility of fibers being separated from the tampon. Useful covers are known to those of ordinary skill in the art, and they are generally dimensionally stable with low elongation in both the machine and cross-direction. They may be selected from an outer layer of fibers which are fused together (such as by thermobonding), a nonwoven fabric, an apertured film, or the like. Preferably, the cover has a hydrophobic finish.
While liquid permeable covers are beneficial additions to radially-compressed tampons, their dimensional stability can produce some processing challenges. For example, radially compressing a cylindrical tampon blank having a dimensionally stable cover disposed about the cylindrical outer surface can result in cover wrinkles or loose cover extending from the outer surface of the compressed tampon pledget. Therefore, many processes involving radial compression of a tampon blank account for this by folding or tucking the cover material into grooves or folds that penetrate relatively deeply into the absorbent structure.
A process useful in the formation of an intravaginal tampon for feminine hygiene of the present invention with grooved zones begins with an open fibrous structure. The open structure may be a nonwoven fibrous web, a mass of randomly or substantially uniformly oriented fibers and optional materials, such as foams, or particles, and the like. This mass is then manipulated to form a tampon blank.
A nonwoven web useful in the present invention can be formed in any manner desired by the person of ordinary skill in the art. For example, fibers can be opened and/or blended by continuously metering them into a saw-tooth opener. The blended fibers can be transported, e.g., by air through a conduit to a carding station to form a fibrous web. Alternatively, a mass of substantially randomly oriented fibers can be formed by opening and/or blending them, transporting them, as above, to a station to form, e.g., a teabag-type tampon blank. Further processes may employ oriented fibers in a fibrous tow.
The tampon blank can be further processed to form a tampon. In a tampon forming process, a web can be formed into a narrow, fibrous sliver and convolutedly wound to form a tampon blank. In addition, a liquid-permeable cover material can be wrapped around the tampon blank to substantially contain the fibrous absorbent portion of the tampon. It may be desired to process the fibrous sliver with selective needle-punching of the sliver as disclosed in U.S. Pat. No. 7,845,055 to Kimball et al., the disclosure of which is herein incorporated by reference.
As shown in FIGS. 7-16 , the intravaginal tampon for feminine hygiene of FIG. 1 having a predetermined finished diameter can be formed in a press 100 having (1) a generally cylindrical press cavity 102 having a central press axis 104 and a substantially cylindrical circumference and (2) a plurality of elongate press dies. A partially broken-away perspective view of the press 100 is shown in FIG. 7 . This figure includes only seven of sixteen press dies and a portion of the press cam removed for clarity. The press dies may include penetrating dies 106 having pressing faces for defining a set of penetrating grooves that extend into the finished tampon pledget and shaping dies 108 for forming surface features, including shallow grooves on the outer surface of a resulting compressed tampon pledget, or smoothing the outer surface of a resulting compressed tampon pledget, or forming a continuous diameter for guiding resulting compressed tampon pledget out of the press during the ejection step. The penetrating dies 106 and shaping dies 108 alternate about the circumference of the cylindrical press cavity.
More detail of the press dies can be seen in FIG. 8 , an enlarged view of the bottom right four press dies of FIG. 7 . In this view, a first penetrating die 106 a has a pressing face 107 and shape corresponding to groove segment 41 and a second penetrating die 106 b has a shape corresponding to groove segment 42 (of FIG. 1 ). As can be seen in FIG. 8 , one end 150 a of the first penetrating die 106 a extends beyond the corresponding end 150 b of the second penetrating die 106 b . Indeed, the end 150 b of the second penetrating die 106 b is curved toward the first penetrating die 106 a in order to form the turn 43 in the surface of the tampon pledget 20 (as shown in FIG. 1 ) proximate to the insertion end 22 . In this embodiment, the end 150 a of the first penetrating die 106 a corresponds to the insertion end 22 of the tampon pledget 20 of FIG. 1 .
Turn 43 of the detached groove form 40 is formed by the intersection between groove segments 41 and 42 (see FIG. 1 ). To form a groove form 40 , the penetrating dies 106 a , 106 b travel on a path that crosses during the compression of the tampon blank 200 (see FIG. 9 ) to form the pledget 20 . Therefore, the longer penetrating die 106 a has a notch 152 formed (see FIG. 8 ) proximate to, although spaced from, the end 150 a to permit the end 150 b of penetrating die 106 b to pass across the path of travel of penetrating die 106 a.
The shaping dies 108 are shaped to accommodate the shape of the penetrating dies 106 disposed therebetween. Thus, shaping die 108 a corresponds to the surface of the pledget 20 contained by the groove segments 41 and 42 and the turn 43 . This shaping die 108 a is shorter than shaping die 108 b corresponds to the surface of the pledget 20 that is open to the insertion end 22 .
In the foregoing description, the grouping of the four press pieces may be repeated four times to provide four “petals” around the circumference of the tampon pledget. Alternatively, there could be three sets of the four press dies to form three “petals” around the circumference of the tampon pledget.
In this process, a substantially cylindrical tampon blank 200 is inserted into the press cavity 102 in an open position shown in FIG. 9 (a cross-section of the press of FIG. 7A and tampon proximate to the notch 152 in the first penetrating die 106 a , looking from the interior of the press toward the end of the press corresponding to the insertion end of the tampon in FIG. 1 ), after which an initial compression step is performed. In this initial compression step, at least the penetrating dies 106 are moved into the press cavity 102 to a penetrating die closed position having a clear distance “r” (see FIG. 11 ) from the press axis 104 that is less than the predetermined finished diameter as shown in FIG. 10 and in detail in FIGS. 11 and 12 . This causes portions of adjacent penetrating dies that form the turn to pass through the same space within the press. As shown in FIG. 12 , this can be accomplished by forming a notch 152 in the first penetrating dies 106 a to permit the second penetrating dies 106 b to cross therethrough in the penetrating die closed position. This initial compression step forms the compressed fibrous core of the tampon and provides column strength for easy insertion without need for a tampon applicator, known in the art as digital insertion.
In one embodiment, a second compression step that applies to the substantially longitudinal ribs of the preform a radial pressure directed toward the central press axis to provide a compressed tampon pledget of reduced diameter relative to the preform is represented in FIG. 13 (a cross-section of the press, proximate to the center of the press cavity) and 14 (an end view of the press). In this step, the penetrating dies 106 are retracted to assume a clear distance from the press axis that is sufficient to permit the shaping dies 108 to advance toward the press axis beyond the penetrating dies. Then the set of shaping dies is moved to a shaping die closed position. The compressed tampon pledget may be ejected from the press cavity 102 using the shaping dies 108 to provide a substantially smooth guide for the compressed tampon pledget to permit removal of the compressed tampon pledget from the press and pushing on one end of the compressed tampon pledget with a push rod 110 (shown in FIG. 15 ).
The tampon can be further shaped and packaged. For example, the insertion end can be formed into a hemispherical or elliptical dome shape, and the tampon can be enclosed in a primary packaging material that can also support the final shape of the tampon.
In somewhat greater detail, the tampon press 100 of FIGS. 7 and 8 includes a cam 120 , penetrating die assemblies 130 , and shaping die assemblies 140 . The cam 120 is generally circular and includes slots 122 to urge the die assemblies 130 , 140 into and out of the press cavity 102 as the cam is pivoted about the press axis 104 . Each penetrating die assembly 130 includes a pair of slides (an exemplary slide 132 is shown on one side of the cam 120 ; another, not shown, would be on the opposite side of the cam 120 ) and the penetrating die 106 . Each shaping die assembly 140 includes a pair of slides (an exemplary slide 142 is shown on one side of the cam 120 ; another, not shown, would be on the opposite side of the cam 120 ) and the shaping die 108 . Alternatively, multiple cams 120 a , 120 b may be used to permit more variability to the control of the movement of the dies, e.g., one cam could operate penetrating dies 106 and another could operate shaping dies.
Upon ejection from the press 100 , compressed pledget 20 is generally cylindrical as shown in FIG. 16 . The pressed groove segments generally extend from the insertion end 22 to the withdrawal end 24 . Those pressed groove segments 50 that extend from the turn 43 to the insertion end 22 of the pledget will essentially be restructured in the doming process mentioned above to substantially eliminate them, both aesthetically and functionally. This is enhanced by the absence of the cover 25 in the region of the dome 23 .
In an alternative embodiment, especially enabled by a multiple cam controlled process, the penetrating jaws 106 a , 106 b may be controlled to advance them separately. For example, penetrating jaw 106 b may be advanced to the closed position, withdrawn sufficiently to permit penetrating jaw 106 a to fully advance toward the press axis 104 in the closed position. This eliminates the need for notch 152 in penetrating jaw 106 a , as the two penetrating jaws do not need to occupy the same space at the same time. In addition, as described in the embodiment, below, this could permit penetrating jaws 106 a to remain in contact with the compressed tampon pledget 20 during ejection from the press.
In an alternative process, shown in FIGS. 17-18 , the shaping dies 108 may be eliminated. Again, a substantially cylindrical tampon blank 200 is inserted into the press cavity 102 in an open position (similar to that shown in FIG. 9 ), after which an initial compression step is performed. In this initial compression step, at least the one set of penetrating dies 106 b are moved into the press cavity 102 to a penetrating die closed position having a clear distance from the press axis 104 of less than a final compressed radius of the compressed tampon pledget as shown in FIG. 17 . The first set of penetrating dies 106 b are withdrawn sufficiently to permit penetrating jaw 106 a to fully advance toward the press axis 104 in the closed position. The penetrating jaws 106 a may remain in contact with the compressed tampon pledget 20 during ejection from the press. This compression forms the densified fibrous core of the tampon and provides column strength for easy insertion without need for a tampon applicator, known in the art as digital insertion. The compressed tampon pledget is ejected from the press cavity 102 into a reducing bushing to transfer the compressed pledget into a hollow mandrel by pushing on one end of the compressed tampon pledget with a push rod 110 (similar to that shown in FIG. 15 ).
While the foregoing detailed embodiments describe tampons having four groove forms resulting from eight intersecting groove segments, it will be recognized that the number of groove forms and/or groove segments can be varied, as desired. There may be an even or odd number of groove forms and/or groove segments—for example, embodiments similar to that shown in FIG. 6 could have three or four groove forms separated by an equal number of additional grooves. Thus, a three groove form structure with three additional grooves could be formed with a combination of six intersecting groove segments (forming the three groove forms) and three additional grooves; a total of nine groove segments and/or grooves. A corresponding number of penetrating dies would be required in contrast with the sixteen penetrating dies described in reference to FIGS. 7-16 , above. A line drawing of the pressing faces 107 of a set of three adjacent penetrating dies for such an embodiment is shown in FIG. 19 . In this drawing, penetrating dies 106 a ′, 106 b ′ create the groove form, while independent penetrating die 106 c forms the additional groove 44 between groove forms 40 ′ of FIG. 6 .
The specification and embodiments above are presented to aid in the complete and non-limiting understanding of the invention disclosed herein. Since many variations and embodiments of the invention can be made without departing from its spirit and scope, the invention resides in the claims hereinafter appended.
|
The present invention relates to an intravaginal tampon for feminine hygiene. In particular, it relates to methods for producing such a tampon having relatively deep, penetrating grooves in which adjacent penetrating jaws pass through the same tampon press space during manufacture and to an apparatus useful in making such a tampon as well as the tampons made therewith.
| 0
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.